Human anatomy and physiology - Secondary Sciences - home - MOAM.INFO (2023)

Human Anatomy and Physiology, 8th edition, by Elaine N. Marieb and Katja Hoehn. Each chapter has been designed in a way that we hope you will find in your...

Guide for text and media teachers

Human Anatomy and Physiology Eighth Edition

Theresa Bissell Community College Ivy Tech

Laura Steele Ivy Tech Community College

Benjamin Cummings San Francisco Boston New York Cape Town Hong Kong London Madrid Mexico City Montreal Munich Paris Singapore Sydney Tokyo Toronto

Editor-in-Chief: Serina Beauparlant Assistant Editor: Nicole Graziano Editor-in-Chief: Wendy Earl Production Editor: Leslie Austin Proofreader: Anna Reynolds Trabucco Composer: Cecelia G. Morales Interior Designer: Cecelia G. Morales Cover Design: Riezebos Holzbaur Design Group Senior Manufacturing Buyer: Stacey Weinberger Marketing Manager: Derek Perrigo Cover Photo Credit: © Walter Iooss/Stockton Martel

Copyright © 2010 by Pearson Education, Inc., published as Pearson Benjamin Cummings, 1301 Sansome St., San Francisco, CA 94111. All rights reserved. This publication is copyrighted and the permission of the publisher must be sought before any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording or the like. To obtain permission(s) to use material from this work, submit a written request to Pearson Education, Inc., Permissions Department, 1900 E. Lake Ave., Glenview, IL 60025. For permissions information, go to (847 ) 486-2635 . Many of the terms used by manufacturers and sellers to distinguish their products are considered trademarks. Where such designations appear in this book and the publisher was aware of a trademark claim, the designations were printed in full or in capital letters. Benjamin Cummings is a registered trademark of Pearson Education, Inc. or its affiliates in the US and/or other countries.

ISBN 10:0-321-55876-6; ISBN 13: 978-0-321-55876-3 1 2 3 4 5 6 7 8 9 10–B&B–13 12 11 10 09 Made in USA. UU.

CONTENTS Foreword

Suggested Lesson Structure

ix

What's New: Chapter-by-Chapter Changes in Human Anatomy and Physiology, Eighth Edition XI

cross references

1

activities/demonstrations

cross references

34

reading tips

1

Library research topics

35

35

Material to improve the conference

1

suggested reading

5

6

activities/demonstrations

38

Library research topics

7

Material to improve the conference

7

9

Answers to questions at the end of the chapter

41

Stuff: The living stuff

7

Multimedia in the classroom and laboratory

10

11

Goals

Suggested cross-references for the lesson plan

43

46

Work correlation

47

47

activities/demonstrations

2

43

43

reading tips

48

Critical thinking/topics for discussion

Chemistry comes alive

Library research topics

12

Suggested cross-references for the lesson plan

49

Material to improve the conference

13

suggested reading

19 19

Critical Thinking/Discussion Topics Library Research Topics

20

20

Material to improve laboratory and multimedia teaching in the classroom.

21

23

Answers to the questions at the end of the Recommended Reading chapter

49

51

Answers to questions at the end of the chapter

18

activities/demonstrations

25

24

53

The purposes of the integumentary system

Suggested cross-references for the lesson plan

54

57 58

58

activities/demonstrations

Cells: the living units

26

54

54

Work correlation

3

51

5

reading tips

26

49

Multimedia in the classroom and laboratory

12

reading tips

39

4

6

Critical thinking/topics for discussion

suggested reading

36

Answers to questions at the end of the chapter

5

Work correlation

Goals

33

Multimedia in the classroom and laboratory

1

Suggested Lesson Structure

Goals

33

Critical thinking/topics for discussion

The human body: an orientation goals

33

Proposed classes of laboratory correlations

27

58

Critical Thinking/Discussion Topics Library Research Topics

59

60

iii

4

Text and media guide to human anatomy and physiology

Material to improve laboratory and multimedia teaching in the classroom.

60

95

Work correlation

62

Answers to the questions at the end of the Recommended Reading chapter

cross references

62

reading tips

95

95

activities/demonstrations

63

96

Critical thinking/topics for discussion

6

Library research topics

96

Multimedia in the classroom and laboratory

Bone and skeletal tissue targets

96

Sixty-five

Material to improve the conference

Sixty-five

cross references

Sixty-five

suggested reading

100

9

69

69

activities/demonstrations

muscles and muscle tissue

70

Critical Thinking/Discussion Topics Library Research Topics

70

71

Goals

Material to improve the conference

71

72

Answers to questions at the end of the chapter

cross references

74

reading tips

103

107

Work correlation 73

102

102

Suggested Lesson Structure

Multimedia in the classroom and laboratory

suggested reading

107

107

activities/demonstrations

108

Critical thinking/topics for discussion

7

Library research topics

Goals

76

Material to improve the conference

76

cross references

suggested reading

114

10

83

83

activities/demonstrations

the muscular system

83

Critical Thinking/Discussion Topics Library Research Topics

84

84

Goals

Material to improve the conference

87

Answers to questions at the end of Chapter 89

85

Cross Reference Lesson Tips

116

120

Labor correlation 88

116

116

Suggested Lesson Structure

Multimedia in the classroom and laboratory

suggested reading

120

120

activities/demonstrations

121

Critical thinking/topics for discussion

8 common goals

113

82

Proposed classes of laboratory correlations

77

110

112

Answers to questions at the end of the chapter

Suggested Lesson Structure

109

109

Multimedia in the classroom and laboratory

the skeleton

99

69

Proposed classes of laboratory correlations

98

Answers to questions at the end of the chapter

Suggested Lesson Structure

97

Library research topics

121

Multimedia in the classroom and laboratory

91

Material to improve the conference

91

Suggested Lesson Structure

suggested reading

127

122

124

Answers to questions at the end of Chapter 91

121

125

v

contents

11

Critical thinking/topics for discussion

Fundamentals of the Nervous System and Nervous Tissue 128

Multimedia in the classroom and laboratory

Goals

Answers to questions at the end of the chapter

Library research topics

128

Suggested cross-references for the lesson plan

163

Recommended reading for classroom improvement material

165

133

167

The autonomic nervous system

134

Critical Thinking/Discussion Topics Library Research Topics

135

Material to improve the conference

135 138

Cross Reference Lesson Tips

168

171 171

171

activities/demonstrations

140

172

Critical thinking/topics for discussion

12

Library research topics

141

141 142

suggested reading

174

148

176

special senses

148

Critical Thinking/Discussion Topics Library Research Topics

148

Material to improve the conference

149

177

cross references

153

reading tips

177

181

Work correlation

152

Answers to the questions at the end of the Recommended Reading chapter

Goals

177

Suggested Lesson Structure

149

Multimedia in the classroom and laboratory

182

182

activities/demonstrations

156

182

Critical thinking/topics for discussion

13

Library research topics

The peripheral nervous system and reflex activity 158

Material to improve the conference

Work correlation

162

162

activities/demonstrations

187

159

161

16 The endocrine system

162

Goals

189

184

185

Answers to the questions at the end of the Recommended Reading chapter

Suggested Lesson Structure

reading tips

158

183

183

Multimedia in the classroom and laboratory

cross references

175

fifteen

147

activities/demonstrations

Goals

173

147

Proposed classes of laboratory correlations

Material to improve the conference

Answers to questions at the end of the chapter

Suggested Lesson Structure

172

172

Multimedia in the classroom and laboratory

the central nervous system

168

168

Work correlation

137

Answers to the questions at the end of the Recommended Reading chapter

Goals

Suggested Lesson Structure

135

Multimedia in the classroom and laboratory

cross references

166

14

133

activities/demonstrations

Goals

163

133

Proposed classes of laboratory correlations

129

163

189

186

vi

Text and media guide to human anatomy and physiology

Suggested cross-references for the lesson plan

suggested reading

193

Proposed classes of laboratory correlations

Answers to questions at the end of the chapter

189

activities/demonstrations

19

195

Critical thinking/topics for discussion

195

195

Material to improve laboratory and multimedia teaching in the classroom.

195

The Cardiovascular System: Blood Vessels 223 targets

223

Suggested Lesson Structure

198

Answers to the questions at the end of the Recommended Reading chapter

198

cross references

Goals

230 231

Critical Thinking/Discussion Topics Library Research Topics

201

cross references

suggested reading

205

205

activities/demonstrations

206

Critical Thinking/Discussion Topics Library Research Topics

207

Material to improve laboratory and multimedia teaching in the classroom.

207

208

Answers to the questions at the end of the Recommended Reading chapter

206

209

211

237

THE LYMPHATIC SYSTEM AND THE LYMPHOID ORGANS AND TISSUES 239 targets

239

Suggested cross-references for the lesson plan

239

241

241

activities/demonstrations

241

Critical Thinking/Discussion Topics Library Research Topics

The cardiovascular system: the heart 212

Material to improve the conference

Suggested cross-references for the lesson plan

suggested reading

215

Proposed classes of laboratory correlations

216 217

Critical Thinking/Discussion Topics Library Research Topics

217

217

Material to improve laboratory and multimedia teaching in the classroom.

243

245

21

216

activities/demonstrations

242

243

Answers to questions at the end of the chapter

212

241

242

Multimedia in the classroom and laboratory

212

235

20

reading tips

18

232

234

Answers to questions at the end of the chapter

205

Proposed classes of laboratory correlations

Material to improve the conference

201

231

231

Multimedia in the classroom and laboratory

201

Suggested Lesson Structure

Goals

230

activities/demonstrations

17

224

229

Work correlation

200

reading tips

Sangre

222

194

194

Library research topics

220

220

218

The immune system: purposes of innate and adaptive body defenses

246

Suggested Lesson Structure

247

246

Index cross-references

Proposed classes of laboratory correlations

24

251 251

251

activities/demonstrations

Nutrition, metabolism and regulation of body temperature

252

Critical Thinking/Discussion Topics Library Research Topics

Goals

293

Suggested Lesson Structure

253

Material to improve laboratory and multimedia teaching in the classroom.

253

Cross Reference Lesson Tips

255

Answers to the questions at the end of the Recommended Reading chapter

252

256

299

299

Activities/demonstrations Library research topics

22 260

suggested reading

Cross Reference Lesson Tips

the urinary system

activities/demonstrations

Goals

268

Critical thinking/topics for discussion

269

Material to improve the conference

270

Suggested Lesson Structure

Answers to questions at the end of the chapter

273

308

313

Proposed classes of laboratory correlations

272

308

308

cross references

269

Multimedia in the classroom and laboratory

suggested reading

306

25

267

268

Library research topics

313

313

activities/demonstrations

314

Critical thinking/topics for discussion

274

Library research topics

23

Material to improve the conference

The digestive system

276

suggested reading

Cross Reference Lesson Tips

26

282

Work correlation

283

Fluid, Electrolyte and Acid-Base Balance 322

283

activities/demonstrations

284

Critical Thinking/Discussion Topics Library Research Topics

Material to improve the conference

Goals

322

Proposed lesson plan 285

cross references

289

reading tips

323

327

Work correlation

288

Answers to questions at the end of Chapter 292

285

285

Multimedia in the classroom and laboratory

suggested reading

320

277

327

327

activities/demonstrations

328

315

317

Answers to questions at the end of the chapter

276

314

315

Multimedia in the classroom and laboratory

Suggested Lesson Structure

304

261

267

Work correlation

301

303

Answers to questions at the end of the chapter

260

301

301

Material to improve the conference

Suggested Lesson Structure

Goals

300

Multimedia in the classroom and laboratory

The purposes of the respiratory system

294

Critical thinking/topics for discussion

258

293

318

VIII

VIII

Text and media guide to human anatomy and physiology

Critical Thinking/Discussion Topics Library Research Topics

328

328

Material to improve laboratory and multimedia teaching in the classroom.

329

330 331

333

361 361

Suggested Lesson Outlines Cross References Teaching Tips

364

364

activities/demonstrations

reproductive system

334

cross references

Library Research Topics 335

Suggested Reading 341

342

Material to improve laboratory and multimedia teaching in the classroom.

369

Attachments

342

Appendix A: Guide to Audiovisual Resources

345

Appendix B: Visual Resource Guide

344

Answers to questions at the end of chapter 346.

musculature

473

nervous system i

484

Pregnancy and human development 348

Nervous system II Respiratory system

Suggested Lesson Structure

348

urinary system

353 353

Hormonal system

353

activities/demonstrations

354

Critical thinking/topics for discussion

Material to improve the conference

355

357

Answers to the questions at the end of Chapter 360

354

355

Multimedia in the classroom and laboratory

suggested reading

500

519

529

Fluid, electrolyte and acid-base balance

Work correlation

Library research topics

375

492

System cardiovascular

348

reading tips

371

Appendix C: Interactive Physiology Worksheets 472

28 cross references

367

341

Critical thinking/topics for discussion

suggested reading

365

367

Answers to questions at the end of the chapter

340

Library research topics

364

Reading Improvement Material 340

activities/demonstrations

364

Multimedia in the classroom and laboratory

339

Proposed classes of laboratory correlations

364

Critical thinking/topics for discussion

334

Suggested Lesson Structure

Goals

361

364

Work correlation

27 Tore

inheritance goals

Answers to the questions at the end of the Recommended Reading chapter

29

358

538

547

digestive tract

559

immune system

579

Appendix D: Answers to Interactive Physiology Worksheet 601 Appendix E: Correlation Guide for A.D.A.M. ® Interactive Anatomy (AIA) 618

FOREWORD

This text and media teacher guide has been updated and revised to accompany Human Anatomy and Physiology, 8th Edition, by Elaine N. Marieb and Katja Hoehn. Each chapter has been designed in a way that we hope will benefit you in using the text and teaching its lessons. At the beginning of each chapter is a list of chapter goals that correspond to those listed in each chapter section. A detailed suggested lesson plan is provided for each chapter to help you develop your own course plan. In addition, there are cross-references that point to concepts in other chapters of the text to facilitate the integration of further information. Each chapter contains teaching tips and activities/demonstrations that may be helpful in presenting the material in a way that is more meaningful to the students. There are also critical thinking/discussion topics and library research topics for use in class discussions or as external assignments that can enhance students' understanding of the material being taught. The chapters in this Instructor Guide list various resources that may be helpful in making your presentations more engaging or effective. Lab, classroom and lab plans (including descriptive lists of videos and software, and online resources for students) and materials to enhance teaching (overheads and images on the teacher resource DVD) are available to coordinate with your presentation. A recommended reading list contains articles relevant to the system discussed in the chapter. In addition, the answers to the questions on the short essay at the end of the chapter and the questions on critical thinking and clinical application are provided with page references that point to the main text. A list of online student resources shows the organization of the chapter guide page in myA&P™ (www.myaandp.com) and CourseCompass™ (www.coursecompass.com). Each chapter guide organizes all online media resources in one convenient location, with links to eBooks for each section of Human Anatomy & Physiology, Eighth Edition. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx 8.0™ and other online learning tools. See the Media Preview section at the front of your book for more information. Appendix A is a guide to audiovisual distributors and their contact information. Appendix B contains thumbnails of all textbook images, including illustrations, photos, and tables, organized by chapter. Appendix C contains Dr. Shirley Whitescarver and Brian Witz created Interactive Physiology® worksheets for use with the Interactive Physiology® 10 system suite. Answers to these worksheet questions can be found in Appendix D. Finally, Appendix E contains a correlation guide between selected Knowledge Review questions from the main text and the A.D.A.M. Interactive Anatomy (AIA) CD-ROM.®, Version 4.0. This helps students find the most relevant view to answer questions that require critical thinking. An electronic version of this guide and other faculty supplements are available for download from the Pearson Higher Education-Benjamin Cummings catalog page. Visit www.pearsonhighered.com and select Instructor Resources in Human Anatomy and Physiology, Eighth Edition, by Elaine Marieb and Katja Hoehn.

ix Copyright © 2010 Pearson Education, Inc.

X

Text and Media Human Anatomy and Physiology Teacher's Guide The Internet is an excellent resource for you and your students to find additional information on A&P topics. For a general list of A&P websites, search "anatomy" or "physiology" on search engines such as Google or Yahoo. Here are some websites that you may find useful, but please note that we cannot guarantee that these links will remain active. www.medtropolis.com The Virtual Body includes interactive presentations on various body systems, including animations, narration and quizzes. www.nlm.nih.gov The US National Library of Medicine contains general health information and the Visible Human Project, which produces anatomical images of the male and female human body. www.nlm.nih.gov/medlineplus Medline is a healthcare database maintained by the National Library of Medicine of the National Institutes of Health. www.nih.gov The National Institutes of Health is an excellent resource for general health information; A good source for research topics. www.npac.syr.edu Syracuse University's Center for Parallel Architectures of the Northeast developed the Visible Human Viewer (based on the Visible Human Project) that lets you examine a cadaver layer by layer from different angles. Anatomy and physiology are fascinating subjects that students continue to enrich. We hope that you will find this guide a valuable partner in your teaching endeavors and that the resources it provides will enable you to provide an effective and enjoyable learning experience for your students. Comments and suggestions are always welcome. They may be mailed to Benjamin Cummings, 1301 Sansome Street, San Francisco, CA, 94111.

THERESA BISSELL und LAURA STEELE Ivy Tech Community College, Ft. Wayne, IN

Copyright © 2010 Pearson Education, Inc.

WHAT'S NEW: CHAPTER-BY-CHAPTER CHANGES IN HUMAN ANATOMY AND PHYSIOLOGY, EIGHTH EDITION

Chapter 1 The human body: an orientation ●

New separate section for each different survival need

A new style for homeostatic imbalance figures has been introduced and is featured throughout the book.

New PET scan for a closer look at medical imaging

Chapter 2 Chemistry comes alive ●

A new tabbed header format has been added to select molecular figures in this chapter, allowing comparison of different types of molecules and reactions. Comparative examples include: • New figure comparing three basic types of mixtures, with pictures (Figure 2.4) • New figure comparing dehydration and hydrolysis synthesis (Figure 2.14)

Updated information on molecular chaperones1

Chapter 3 cells: the housing units ●

Images have been reimagined and text added to provide steps that guide students through challenging cellular processes: • New step art for exocytosis (Figure 3.14) • Updated discussion of types of endocytosis accompanied by new step art for endocytosis (Figure 3.14 ) 3.12) • New Figure shows a comparison of three types of endocytosis (Figure 3.13) • A new and easy to understand explanation of how G proteins regulate cellular activities and their mechanisms of action, accompanied by a new step-by-step art (Figure 3.16) • New figure on the signaling mechanism to target new proteins to the ER (Figure 3.20)

The new focus images in this chapter guide students through the key concepts that are most difficult to grasp: • Focus on primary active transport: the Na+-K+ pump (Figure 3.10) • Focus on G proteins (Figure 3.10) 3.16) • Focus on mitosis (Fig. 3.33)

New figures and photographs: • New diagrams accompany the photographs in the figure, showing the effects of different tonicities on bright red blood cells (Figure 3.9) • New photomicrographs accompany illustrations of cell organelles

New information on the origin of peroxisomes based on recent research:2 • New image in microvilli shows photomicrograph (Figure 3.28). New section on microvilli in cell smears section. • New overview of the three stages of transcription, structuring of the text description according to Figure 3.35; Restructured and revised text discussion and Figure 3.37 for translation for clarity Copyright © 2010 Pearson Education, Inc.

XI

xi

Text and media guide to human anatomy and physiology

Chapter 4 Cloth: The Living Cloth ●

The new Figure 4.1, Overview of the four tissue types, gives an overview before going into detail.

New photomicrographs of pseudostratified ciliated epithelium (Figure 4.3d), goblet cells (Figure 4.4), and elastic connective tissue (Figure 4.8f)

The new Table 4.1 compares four major classes of connective tissue

A closer look at cancer updated

Chapter 5 The Skin System ●

New Figure 5.3, Two regions of the dermis, with three new photomicrographs

New Figure 5.4, Dermal changes resulting in characteristic skin markings, with a new photomicrograph

The new paragraph covers how changes in nail color help diagnose certain medical conditions

New photos show partial and full thickness burns (Figure 5.10)

Added eczema and rosacea to related clinical terms

Chapter 6 Bones and Skeletal Tissues ●

The new figure 6.4 shows the comparative morphology of bone cells, comparing osteogenic cells, osteoblasts, osteocytes and osteoclasts.

The new Figure 6.14 explains how vigorous exercise can lead to large increases in bone strength.

Updated information on homocysteine ​​as a marker for low bone mass density and bone fragility

Additional details on age-related bone changes and treatments

Chapter 7 The Skeleton ●

This chapter contains all-new bone art with realistic colors and textures, incorporating many new photos of bones to compare side-by-side with the illustrations: • New photos for the top and bottom views of the skull (Figures 7.6b, 7.7 b ) • New photograph of the mid-sagittal section of the skull (Figure 7.5c) • New photograph of the sphenoid bone, superior and posterior view (Figure 7.9) • New photograph of the right lateral view of the maxilla in the detailed anatomy map of the mandible and maxilla (Fig. 7.11) • New MRI of the lumbar region in the sagittal section with disc herniation (Fig. 7.17) • New photo of the mid-sagittal section of the thorax (Fig. 7.34) • New illustration and photo of the C-shaped spine of a newborn (Fig. 7.37) • New homeostatic imbalance: posterior xiphoid process • Added guidance for palpation of jugular notch • Added two new illustrations/views to depict Added radius and ulna: proximal section of ulna, lateral view w and distal ends of radius and ulna at wrist (Figure 7.27) • Bones of left hand: added rear view illustration (Figure 7.28)

Copyright © 2010 Pearson Education, Inc.

what's new

Chapter 8 Together ●

Figure 8.1 enlarged to show a comparison of different types of fiber joints; Added Gomhose

Added sixth distinguishing feature of synovial joints: nerves and blood vessels.

Added a new part to depict the knee joint relationships: Representation of the plan view of the right tibia in the knee joint (Figure 8.8b)

Added two new parts of the figure at the shoulder joint: illustration of the front section through the shoulder joint and the accompanying photo of the corpse (figure 8.10)

A top view of the mandible has been added to the illustration at the temporomandibular joint (Figure 8.13).

Chapter 9 Muscles and Muscle Tissue ●

Chapter 9 introduces all the physiological concepts of skeletal muscle fibers, including action potential generation, excitation-contraction coupling, and the cross-bridging cycle. The concepts have been rewritten using more explanatory language that aligns the text and figures, and breaks the text into steps and numbered lists. Accompanying the new explanations are several new focus images: • Focus on events at the neuromuscular junction (Figure 9.8) • Focus on excitation-contraction coupling (Figure 9.11) • Focus on the cross-bridge cycle (Figure 9.12)

This chapter also introduces many new and redesigned figures to illustrate key concepts: • The figures depicting the composition of thick and thin filaments (Figure 9.3) and the pathways for ATP regeneration during muscle activity (Figure 9.19), include a new tabular style for easy comparison. New photomicrographs showing transition between stages in sliding filament contraction theory; corresponding stage numbers have been added to the text (Figure 9.6) • New flowchart summarizing the phases leading to muscle fiber contraction (Figure 9.7) • For simplicity, we have removed the permeability curves from the figure showing the action potential; Added depolarization and repolarization points to the action potential curve (Figure 9.10) • New figure comparing short and long term loading (Figure 9.20) • New photomicrograph showing the cross-section of three types of fibers in the musculoskeletal (Figure 9.24) • New figure showing formation a multinucleated skeletal muscle fiber by myoblast fusion (Fig. 9.30)

Chapter 10 The Muscular System ●

In Chapter 10, the changes make it easier to navigate and understand; Highlighting in the muscle gallery tables identifies the primary action element of the muscles so that students can easily find this important information.

The chapter also presents new, high-quality photos of cadavers side by side, with illustrations for easy comparison: the anterior and lateral regions of the neck (Figure 10.9c), superficial muscles of the rib cage (Figure 10.13b), muscles affecting the shoulder and elbow joints crossing (Fig. 10.14d) and the superficial muscles of the upper gluteal region (Fig. 10.20b). Copyright © 2010 Pearson Education, Inc.

XIII

xiv

Text and media guide to human anatomy and physiology

Chapter 11 Fundamentals of the Nervous System and Nervous Tissue ●

Chapter 11 introduces three new focus pictures that guide students step-by-step through the most difficult topics essential to understanding the nervous system: • Focus on the resting membrane potential (Figure 11.8) • Focus on the action potential (Figure 11.11) • Concentrate refers to the chemical synapse (Figure 11.17)

Updated and expanded content reflects current research in this area: • Updated function of satellite cells based on newer research • Updated discussion of nitric oxide and carbon dioxide to reflect current research • Added paragraph on a class of endocannabinoid neurotransmitters recently discovered to reflect current research3 • Updated role of neurotropins in growth cone signaling during neuronal development • Updated information in A Closer Look to Overcoming Cocaine Addiction • Updated information on neurotransmitters (histamine, somatostatin, substance P, CCK) in Table 11.3 to reflect current research to reflect

New images and content: • New image dealing with the propagation and decay of a graded potential (Figure 11.10) • New figure explaining how myelin accelerates action potential propagation (Figure 11.15) • New photograph of a neuronal growth cone (Figure 11.24 ) • Completely new organization and structure to Table 11.2, with added art, comparison of the main features of action potentials and graded potentials

Chapter 12 The Central Nervous System ●

Chapter 12 contains many updated discussions in line with current research: • Updated location of the cortex receiving vestibular information based on new fMRI studies • New homeostatic imbalance in brain tumors in different brain regions: the anterior association area and the posterior parietal region • Regulation of Spinal cord breathing rhythm updated to reflect recent research • Updated appearance of theta waves in adult EEG • Updated sleeping and waking mechanisms. Updated role of orexins (hypocretins) in narcolepsy. Added a new finding that orexin antagonists promote sleep in humans. • Current information on stroke survival and treatment • Current research on the cause and treatment of Parkinson's disease • Current treatments for Alzheimer's disease • Current discussion on sensory and motor pathways; rearranged for clarity and aligned to the order in Table 12.2 • Updated information on folic acid intake and incidence of spina bifida

This chapter also introduces several new photos: • New photo of the frontal section of the brain (Figure 12.10) • New photo of the bottom view of the brain showing the brainstem regions (Figure 12.14) Copyright © 2010 Pearson Education, Inc.

What's new • New image of the cerebellum, with a new image and a new accompanying illustration (Figure 12.17) • New EEG image (Figure 12.20)

Chapter 13 The peripheral nervous system and reflex activity ●

Discussions updated according to current research: • Axon regrowth and treatment of spinal cord injury to reflect current research • Homeostatic imbalance in the cause and treatment of trigeminal neuralgia • Origin and course of accessory nerves (CN XI)4

This chapter also introduces a new focus figure, Focus on the Stretch Reflex (Figure 13.17), and new realistic nerve art for nerve boards. We also included two new cadaver photos for the brachial plexus (Figure 13.9) and the sacral plexus (Figure 13.11). The previous table from A Closer Look at Pain is now integrated into the text, and we've added a new homeostatic imbalance for hyperalgesia and phantom limb pain.

Chapter 14 The autonomic nervous system ●

New homeostatic imbalance in autonomic neuropathy

Updated hepatic parasympathetic effects in Table 14.4

Updated treatment of spinal cord injury in end-of-chapter problem

Chapter 15 The Special Senses ●

Chapter 15 presents content updates based on recent research in the following areas: • Laser methods to correct myopia • The light adaptation mechanism in rods5 • Olfactory signal processing6 • Taste cell specificity: According to current understanding, there is no overlap of taste modalities in a taste (each taste cell transmits only one modality) , but the taste buds respond to all five modalities. • The transduction mechanism for the five taste modalities7 • Treatment of age-related macular degeneration in related clinical terms

Chapter 16 The Endocrine System ●

Additional top-level headings in Chapter 16 allow for easier chapter navigation.

New figures and photos: • The new figure 16.7, regulation of thyroid hormone secretion, emphasizes the basic hierarchy of hormone regulation from the hypothalamus to the anterior pituitary to the target organ and the associated negative feedback.

Updated information: • Updated information on hormones released by the thymus and adipose tissue • Added new information on incretins and osteocalcin • A closer look at diabetes mellitus, simplified and updated to reflect current research: updated treatments, drug delivery methods, insulin, clinical Studies, studies, statistical islet transplantation and pumps for continuous glucose monitoring

Copyright © 2010 Pearson Education, Inc.

XV

XVI

Text and media guide to human anatomy and physiology

Chapter 17 Blood ●

Update: • Updated discussion of erythropoietin based on current research, with a new understanding of how hypoxia induces erythropoiesis8 • Updated discussion of treating sickle cell anemia with the new drug clotrimazole • Updated role of eosinophils based on current research9

The reorganized and clarified discussion of platelet clot formation now includes chemical messenger markers. The coagulation section has been rewritten and reinforced with additional vignettes comparing the intrinsic and extrinsic pathways in phase 1. A new step-by-step guide provides a simplified picture of the intrinsic and extrinsic pathways of clotting: • Table 17.3 has been condensed and simplified, and includes a separate column for the source of each blood clotting factor.

Chapter 18 The Cardiovascular System: The Heart ●

Several new photographs have been added to this chapter, including a new cadaver photograph of a view of the posterior surface of the heart (Figure 18.4) and a new photomicrograph of the heart muscle (Figure 18.11).

New step-by-step text with corresponding steps in the text discussion has been added to many of the figures in this chapter to facilitate understanding of these difficult subjects, including: • action potential of cardiac muscle contractile cells (Figure 18.12); Clear and simplified step-by-step text accompanying the figure • Pacemaker and action potentials of autorhythmic cells of the heart with corresponding text description (figure 18.13) • Cardiac depolarization and repolarization sequence with added color key to distinguish the two phases (figure 18.17)

Chapter 19 The Cardiovascular System: Blood Vessels ●

Updated information: • Updated role of pericytes based on new research • Updated discussion of relationship between obesity and hypertension based on new research • Updated discussion on development of arteries and veins based on new research • New research summary to indicate that systolic BP a better predictor of complications of hypertension in people over 50 • Updated section on hypertension and its treatment to mention angiotensin II receptor blockers

Chapter 20 The Lymphatic System and Lymphoid Organs and Tissues ●

Added Interactive Physiology® references to the chapter summary at the end of the chapter for the new Immune Module.

Updated information on Hassall bodies from Current Research10

Copyright © 2010 Pearson Education, Inc.

what's new

Chapter 21 The Immune System: Innate and Adaptive Defenses ●

Updated Information: • Added Dermcidin as a key antimicrobial agent in human sweat. • Updated number of human TLR types from 10 to 11 based on recent research. • Information updated to reflect new discovery that dendritic cells can obtain foreign antigens from infected cells through Gap11 junctions • Updated role of TH2-type T helper cells in immunity. • Updated statistics on HIV/AIDS. • Updated information on treatments for autoimmune diseases and multiple sclerosis

New images, photos and content: • New phagocytosis micrograph and new accompanying illustrations (Figure 21.2) • New SEM of a dendritic cell (Figure 21.10) • New flow chart comparing active and passive humoral immunity (Figure 21.13) • New computer generated Images from an antibody (Figure 21.14) • New homeostatic imbalance in parasitic worms

Added new interactive physiology references for the new Immune module to the chapter summary at the end of the chapter

Chapter 22 The respiratory system ●

New photomicrograph showing part of the tracheal wall (Fig. 22.6)

Described role of type II alveolar cells in innate immunity12

Updated discussion of the mechanism of hypercapnia after oxygen administration in patients with COPD

Updated discussion on the treatment of cystic fibrosis

Chapter 23 The Digestive System ●

New photos: • New X-ray of a child's mouth showing the permanent incisors forming deep down to the primary incisors (Figure 23.10) • New photomicrograph of the small bowel villi (Figure 23.22) • New photo of a gastric ulcer lesion and SEM of H . pylori bacteria (Fig. 23.16)

Updated information: • Updated discussion of process of HCl formation in parietal cells • Updated and expanded section on small bowel wall histology; additional function of Paneth cell secretions • Figures added to Table 23.2, Overview of the functions of the gastrointestinal organs

Chapter 24 Regulation of nutrition, metabolism and body temperature ●

Chapter 24 includes all-new vitamin and mineral tables that have been simplified to make learning easier for students. New headings and sections have been added to this chapter to facilitate navigation of the material, including: Copyright © 2010 Pearson Education, Inc.

xvii

xviii

Text and Media Human Anatomy and Physiology - Teacher's Guide • New sections and coverage of obesity and the short and long term regulation of food intake and additional regulatory factors13 • New photos, atomic force microscopy showing rotor structure of ATP synthase energy conversion rings (Figure 24.10)

Chapter 25 The urinary system ●

New photos: • New photo of frontal section of kidney (Figure 25.3) • New photomicrograph of nephron tubules sectioned into new image of renal cortical tissue and tubules (Figure 25.6) • New intravenous pyelogram (Figure 25.19)

Updated information and content, and reorganized text: • Updated structure and possible function of extraglomerular mesangial cells • Reorganized text and information on urea recycling and medullary osmotic gradients in a separate section for better understanding • Reorganized section on dilute urine formation or Clarification focused • New homeostatic imbalance in chronic kidney disease and renal insufficiency • Reconceptualized picture of voiding control simplified into a flowchart; Section on urination rewritten for clarity and to match new illustration. • Table 25.1, Reabsorption capacities of various segments of renal tubules and collecting ducts, now an illustrated table with diagrams of nephrons highlighting descriptions

Chapter 26 Fluid, Electrolyte, and Acid-Base Balance ●

Section on the movement of fluids between compartments reorganized to correspond to the new figure on the exchange of gases, nutrients, water and waste between the three fluid compartments of the body.

Additional clarification of the difference between edema and hypotonic hydration.

New paragraph on angiotensin II

Chapter 27 The reproductive system ●

Updated information: • Added new section on Erectile Dysfunction. • Added update on new HPV vaccine. • Expanded discussion of interactions along the hypothalamic-pituitary-ovarian axis with a reconceptualized map. • Updated information on transmission of herpes viruses. • Updated discussion on descending testicles. • Updated information on hormone replacement therapy for women

New photos: • New SEM of sperm (Figure 27.8) • New micrograph of the ovary showing follicles at different stages of development (Figure 27.11) • New micrograph of the endometrium and its blood supply (Figure 27.13)

Copyright © 2010 Pearson Education, Inc.

What's New • New image of the mammography procedure and new images of a normal mammography versus one showing a tumor (Figure 27.16) • Added stepping text to the illustration and text description of the follicular phases; added six new photomicrographs showing the stages of follicular development (Figure 27.18)

Chapter 28 Pregnancy and Human Development ●

Appropriate step text has been added to the figure and text description for Figure 28.2, Sperm penetration and cortical response, and for Figure 28.3, Fertilization events.

New photos and figures: • New photomicrograph of a blastocyst recently attached to the uterine endometrium (Figure 28.5) • New figure showing the detailed anatomy of the vascular relationships in the mature basal decidua (Figure 28.8) • New flow chart showing the main derivation from the Embryonic phase showing cotyledons (Fig. 28.13)

Current information on: • the start of labor • contraception (in detail)

Chapter 29 Inheritance ●

New photos and figures: • New photo of human sex chromosomes (Figure 29.5) • New discussion of genealogy with a new image (with images) of a family tree tracing the trait called widow's peak through three generations (Figure 29.7) • New image for comparison of Fetuses from amniocentesis and chorionic villus sampling (Figure 29.8)

Current information: • Current information on stem cell research based on current research • Current information on epigenetics and non-traditional methods of gene regulation14

References 1. Srivastava, PK “New Jobs for Old Escorts.” Scientific American 299 (2008): 50–55. 2. Hoepfner, D., et al. "Contribution of the endoplasmic reticulum to peroxisome formation". Cell 122 (2005): 85-95. 3. Berghuis, P., et al. "Brain Wiring: Endocannabinoids Shape Neural Connectivity". Science 316 (2007): 212–216. Harkany, T., et al. "The emerging functions of endocannabinoid signaling during CNS development". Trends in Pharmacological Science 28(2) (2007): 83-92. Woods, SC "Role of the endocannabinoid system in the regulation of cardiovascular and metabolic risk factors." American Journal of Medicine 120(3A) (2007): S19-S20. 4. Lachman, N., et al. "Anatomical evidence for the absence of a morphologically distinct cranial root of the accessory nerve in man". Clinical Anatomy 15 (2002): 4–10.

Copyright © 2010 Pearson Education, Inc.

xix

XX

Text and media guide to human anatomy and physiology

5. 6. 7.

8. 9.

10

11. 12. 13.

14

Ryan, S., et al. “Is the accessory nerve really part of the accessory nerve? Anatomy of the cranial nerves in the jugular foramen. International Anatomical Science 82 (2007): 1-7. Fu, Y. and KW Yau. "Phototransduction in mouse rods and cones". Pfluger Archive 454 (2007): 805-819. Zou, Z. and LB Buck. "Combined Effects of Olfactory Mixtures on the Olfactory Cortex". Science 311 (2006): 1477–1481. Chandrashekar, J., et al. "Receptors and cells for taste in mammals". Nature 444 (2006): 288–294. Roper, S.D. "Signal transduction and information processing in the mammalian taste buds." Pfluger Archive 454 (2007): 759-776. Huang, AL, et al. "Cells and the rationale for sour taste recognition in mammals". Nature 442 (2006): 934–938. Ishimaru, Y., et al. "Prospective members of the transient receptor family PKD1L3 and PKD2L1 constitute a candidate sour taste receptor." Proceedings of the National Academy of Sciences 103(3) (2006): 12569–12574. Haase, V. H. "Hypoxia-inducible factors in the kidney." American Journal of Physiology Renal Physiology 291 (2007): F271-F281. Rothenberg, M.E. "Eosinophils in the New Millennium." Journal of Allergy and Clinical Immunology 119(6)(2007): 1321-1322. Jacobsen, E.A., et al. "Eosinophils: Extraordinarily destructive effector cells or providers of immune regulation". Journal of Allergy and Clinical Immunology 119(6)(2007): 1313-1320. Watanabe, N., et al. "Hassall bodies direct dendritic cells to induce CD4+CD25+ regulatory T cells in the human thymus." Nature 436 (7054) (2005): 1181-1185. Li, G. and M. Herlyn. "Information sharing and collateral damage". Trends in Molecular Medicine 11(8)(2005): 350-352. Mason, R.J. "Biology of Type II Alveolar Cells." Respirology 11 (2006): S12-S15. Powell, K. "Obesity: The Two Faces of Fat." Nature 447 (7144) (2007): 525–527. Wisse, B.E., F. Kim, and M.W. black. "An integrative look at obesity". Science 318 (5852) (2007): 928–929. Couzin, J. "Drug avoidance for the treatment of diabetes." Science 320 (5875) (2008): 438–440. Flieger, JS and E. Maratos-Flier. "What nourishes the fat?" Scientific American 297(3) (2007): 72-81. Berger, S. L. "The complex language of chromatin regulation during transcription". Nature (Insight Review) 447 (7143) (2007): 407-411. Bird, A. "Perspectives on Epigenetics." Nature (Insight Review) 447 (7143) (2007): 396-398. Eteller, M. "Epigenetics in Cancer." New England Journal of Medicine 358(11) (2008): 1148-1159. Saey, TH "Epic Genetics: Chemical gene clothing may underpin the biology behind mental illness." Science News 173(16) (2008): 15-19. Zeviani, M. and E. Lamantea. "Genetic disorders of the mitochondrial OXPHOS system". Science and Medicine 10(3) (2005): 154-157.

Copyright © 2010 Pearson Education, Inc.

The human body: an orientation

Goals

1

Homeostasis

An overview of anatomy and physiology 1. Define anatomy and physiology and describe their subdivisions. 2. Explain the principle of complementarity. Levels of Structural Organization 3. List the different levels of structural organization that make up the human body and explain their relationships. 4. Name the 11 organ systems of the body, identify their components and briefly explain the main function(s) of each system. Life support 5. List the functional properties necessary to support life in humans. 6. Make a list of the body's survival needs.

7. Define homeostasis and explain its importance. 8. Describe how positive and negative feedback maintains homeostasis in the body. 9. Describe the relationship between homeostatic imbalance and disease. The Language of Anatomy 10. Describe the anatomical position. 11. Use correct anatomical terminology to describe the directions of the body, the regions of the body, and the planes or sections of the body. 12. Locate and name the major body cavities and their associated subdivisions and membranes, and list the major organs they contain. 13. Name the four quadrants or nine regions of the abdominal cavity and list the organs they contain.

Suggested Lesson Plan I. An Overview of Anatomy and Physiology (pp. 2-3) A. Anatomy is the study of the structure of body parts and their relationships to one another, and physiology is the study of the function of body parts. (p. 2). B. Topics of Anatomy (p. 2) 1. Gross (gross) anatomy is the study of structures large enough to be seen with the naked eye. a. Regional anatomy is the study of all body structures in a specific body region. B. Systemic anatomy is the study of all structures of a body system. C. Surface anatomy is the study of the internal structures of the body in relation to the overlying skin.

1 Copyright © 2010 Pearson Education, Inc.

2

Text and Media Human Anatomy and Physiology Teacher's Guide 2. Microscopic anatomy is the study of structures too small to be seen with the naked eye. a. Cytology is the study of individual cells. B. Histology is the study of tissues. 3. Developmental anatomy is the study of changes in body structures throughout life; Embryology focuses on development before birth. 4. Subjects of anatomy a. Pathology is the study of structural changes associated with disease. B. X-ray anatomy is the study of internal structures using specialized visualization techniques. C. Molecular biology is the study of biological molecules. 5. The essential tools in the study of anatomy are mastery of medical terminology and the development of keen observation skills. C. Physiological Topics (pp. 2-3) 1. Physiology has a variety of topics, most of which deal with the function of specific organ systems. 2. Physiology generally focuses on cellular and molecular processes. D. Complementarity of structure and function (p. 3) 1. The principle of complementarity of structure and function states that function depends on structure and that the form of a structure is related to its function.

II. Structural levels of organization (p. 3; Figs. 1.1, 1.3) A. The chemical level is the simplest level of organization (Fig. 1.1). 1. Atoms, the tiny building blocks of matter, combine to form molecules. 2. Molecules combine in specific ways to form organelles, which are the basic units of living cells. B. The cellular level is the smallest unit of life and varies greatly in size and shape depending on the function of the cells. C. Tissues at the level are groups of cells with a common function. D. The organ level consists of discrete structures composed of at least two groups of tissues that work together to perform a specific function in the body. E. The organ system level is a group of organs that work together to achieve a specific purpose (Fig. 1.3). F. The organism level is the totality of all structures that work together to support life.

3. Life Support (pp. 4-8; Fig. 1.2) A. Necessary Life Functions (pp. 4-8; Fig. 1.2) 1. Boundary maintenance allows an organism to maintain separate internal and external environments, or environments with separate internal chemicals . 2. Movement allows the organism to move through the environment and allows the transport of molecules within the organism. 3. Responsiveness or irritability is the ability to recognize and respond to changes in the internal or external environment.

Copyright © 2010 Pearson Education, Inc.

Chapter 1

The human body: an orientation

4. Digestion is the process of breaking down food into molecules that the body can use. 5. Metabolism includes all chemical reactions that take place in the body. 6. Elimination is the process of eliminating waste. 7. Reproduction is the process of producing more cells or organisms. 8. Growth is an increase in size of parts of the body or of the whole organism. B. Survival Needs (p. 8) 1. Nutrients are spent chemicals used for energy and cell formation. 2. Oxygen is required for chemical reactions that release energy from food. 3. Water, the most abundant chemical in the body, provides an environment for chemical reactions and a fluid medium for secretions and excretions. 4. A normal body temperature is necessary for the body's chemical reactions to proceed at the proper rate. 5. Atmospheric pressure must be within an adequate range for adequate gas exchange to take place in the lungs.

4. Homeostasis (pp. 8-11; Figs. 1.4-1.6) A. Homeostasis is the body's ability to maintain a relatively constant internal environment, independent of environmental changes (p. 8). B. Homeostatic Control Mechanisms (pp. 9 to 11; Figs. 1.4 to 1.6) 1. Components a. Variable: The regulated factor or event. B. Receiver: structure that monitors changes in the environment and sends information to the control center. C. Control Center: A structure that determines the reference point for a variable, analyzes the input, and coordinates an appropriate response. i.e. Effector: structure that carries out the response directed by the control center. 2. Negative Feedback Mechanisms a. Most homeostatic control mechanisms are negative feedback mechanisms. B. A negative feedback mechanism causes the variable to change in the opposite direction of the original change. C. Both the nervous and endocrine systems are important in maintaining homeostasis. i.e. The purpose of negative feedback mechanisms is to prevent sudden and serious changes in the body. 3. Positive Feedback Mechanisms a. A positive feedback mechanism causes the variable to change in the same direction as the original change, resulting in a larger deviation from the setpoint. B. Positive feedback mechanisms often trigger self-sustaining events. C. Most positive feedback mechanisms are not related to maintaining homeostasis. 4. Homeostatic imbalance often leads to disease.

Copyright © 2010 Pearson Education, Inc.

3

4

Text and media guide to human anatomy and physiology

V. The language of anatomy (pp. 11-20; Fig. 1.7-1.12; Tab. 1.1) A. Anatomical position and directional terms (pp. 11-13; Fig. 1.7; Tab. 1.1) 1. Anatomical position is a Position in which the body is upright, palms facing forward and thumbs pointing away from the body. a. In the anatomical position, right and left refer to the right and left sides of the person depicted. B. In anatomy, the anatomical position is always taken, regardless of the actual position of the body. 2. Directional terms are used to explain exactly where one part of the body is in relation to another. B. Regional terms (p. 14; Fig. 1.7) 1. There are two basic divisions of the body. a. The axial region includes the head, neck, and trunk. B. The cecal region consists of the upper and lower limbs. 2. Regional designations denote specific areas within the axial and appendicular divisions. C. Body Planes and Sections (p. 14; Figure 1.8) 1. Body planes are plane surfaces that are at right angles to each other. a. Sagittal plane: vertical plane dividing the body into right and left parts. ME. Median or median sagittal plane: lies exactly on the midline of the body. ii. Parasagittal plane: It is shifted from the midline. B. Frontal plane: Vertical plane dividing the body into front and rear parts. C. Transverse or Horizontal Plane: Plane that runs horizontally from right to left and divides the body into upper and lower parts. 2. Cuts are cuts along specific planes. a. A cross section or cross-section is a cut along the transverse plane. B. Bevel cuts are cuts made at angles between the horizontal and vertical planes. D. Body cavities and membranes (pp. 14-20; Figs. 1.9-1.12) 1. Body cavities are closed body spaces that contain internal organs. 2. The dorsal body cavity is the space that houses the central nervous system and has two subdivisions: the cranial cavity and the vertebral cavity. a. The cranial cavity is inside the skull and houses the brain. B. The vertebral or spinal cavity is located within the spine and houses the spinal cord. 3. The ventral body cavity is present and larger than the dorsal cavity and has two main divisions: the thoracic cavity and the abdominal and pelvic cavities. a. The thoracic cavity is an upper division of the abdominal cavity that is divided into the lateral pleural cavities that surround the lungs. B. The thoracic cavity also contains the mediastinum, which includes the pericardial cavity surrounding the heart and the space surrounding the other chest structures.

Copyright © 2010 Pearson Education, Inc.

Chapter 1

The human body: an orientation

4. The ventral body cavity houses the body's organs or viscera. 5. Membranes in the ventral body cavity a. Serous or serous membranes cover the inner walls of the abdominal cavity and the outer surfaces of the organs. B. The parietal serosa lines the walls of body cavities and is named for the specific cavities to which it is connected. C. The visceral serosa covers the outer surfaces of organs and is named for the specific organs with which it is associated. i.e. The serous membranes secrete and are separated by a thin layer of lubricating fluid called the serous fluid, which allows the organs to slide along the walls of the cavity and over each other without friction. 6. Abdominal-Pelvic Regions and Quadrants a. There are nine abdominal-pelvic regions primarily used by anatomists. B. There are four quadrants primarily used by medical personnel. 7. Other body cavities a. The oral and digestive cavities are continuous cavities that extend from the mouth through the digestive system to the anus. B. The nasal cavity is inside and behind the nose. C. The orbits house the eyes. i.e. The middle ear cavities are inside the skull, in the center of the eardrum, and house the bones that transmit sound vibrations to the inner ear. Y. Synovial cavities are joint cavities lined by a lubricating, fluid-secreting membrane that connects to all movable joints.

Cross-references For more information on the topics covered in Chapter 1, see the chapters listed below. 1st 2nd 3rd 4th 5th 6th 7th

Chapter chapter chapter chapter chapter chapter chapter

2: Chemical and physical principles 3: Cellular level of structural organization 4: Tissue level of structural organization 16: Hormonal control as an example of feedback regulation 22: Mediastinal organs 23: Serous membranes of the abdominal cavity 27: Example of positive feedback during the ovarian cycle

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 1: The language of anatomy Exercise 2: Overview of organ systems 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 1: The Language of Anatomy Exercise 2: Overview of Organ Systems

Copyright © 2010 Pearson Education, Inc.

5

6

Text and media guide to human anatomy and physiology

Teaching Tips 1. The Incredible Human Machine is an excellent videotape that provides an exciting overview of many physiological functions. With the help of sophisticated photographic techniques, the wonders of the inner world of the body are revealed. Videotape is inexpensive and available from several suppliers including the Carolina Biological Supply Company. Alternative methods of using the tape are listed below. a. Show the entire video during the class or lab (60 mins). B. Show selected segments of video during an introductory class or lab. C. Show selected sections as an introduction to each body system. i.e. Put the videotape on hold at the library or video center and let the students watch it for themselves. This may be required or optional (if optional encourage viewing by adding bonus points). 2. To illustrate the principle of complementarity between structure and function, ask students to consider the relatively similar structure of a human arm and a bird's wing. Then ask them to consider the functional limitations imposed on the limbs by their shape and the adaptive value of each shape. Manual dexterity versus flying is an excellent example of comparison and contrast. 3. Many students have a very poor understanding of the dynamics of the human body and how it functions in the environment. In this chapter I have tried to emphasize the adaptive nature of the body and the interrelationship between environmental variables and system responses. 4. The body's organ systems are actually an artificial grouping of structures working toward a common goal. Emphasize the interrelationship between organs and systems that make the body "function" as a complete unit. 5. Students can sometimes substitute cardiovascular system for the term circulatory system. Explain the difference and relationship to the lymphatic system. 6. The role of negative and positive feedback systems in maintaining or disrupting homeostasis is fundamental to understanding many of the physiological processes discussed in the text. Emphasize the importance of feedback systems throughout the course. 7. Students often equate the negative term in feedback systems with annoying. This misunderstanding is positively reinforced by the term, which is also used in feedback systems. Emphasize differences and lead by example; For example, describe how a thermostat controls the temperature in the house. 8. Ask the following questions to illustrate the different degrees of protection in the dorsal and abdominal cavities: a. Why do you think a dog instinctively curls up to protect its stomach? B. Two people have rapidly growing tumors: one in the dorsal cavity and one in the abdominal cavity. Which would develop symptoms first? 9. To increase understanding of structure-function relationships, ask students to comment on the relationship between muscle and bone, and between the respiratory and circulatory systems.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Assume the anatomical position and ask why that particular position is important when studying anatomy. Then indicate that any position would be acceptable as long as it is the standard for the anatomical description.

Copyright © 2010 Pearson Education, Inc.

Chapter 1

The human body: an orientation

3. Place a chair in the middle of the stage. Ask a student to indicate how the chair would be cut at the different cutting planes. The answer must include why the other options were not selected. 4. Have students identify the body regions on themselves or a lab partner. Emphasize the use of directional terms when describing their positions relative to each other. 5. Arrange for the class to attend an autopsy (after the material in Chapter 1 has been covered). 6. Use a globe to show the two layers of a serous membrane. 7. Use a torso model and/or dissected animal model to show body cavities, organs, and systemic relationships. 8. Use the thermostat in a classroom (or in a house) to illustrate how a negative feedback system works.

Critical Thinking/Discussion Points 1. Discuss how our intercellular environment can be described as the 'sea within us'. 2. List several embryonic features that form early in the developmental stages but are "lost" or develop into entirely new structures, such as: B. our "tail" (coccyx). 3. If an object were found on Mars that appeared to move and respond to external stimuli, what other properties would be required to classify it as "alive" and why? 4. Compare the type of image obtained with X-ray machines, CT scans, DSR scans and ultrasound. 5. What are the differences between a free-living unicellular organism such as B. a Paramecium, and a single human cell, such as. B. a hair cell in the airways?

Library Research Topics 1st 2nd 3rd 4th

Examine the historical development of anatomy and physiology. Check the current definitions of death and life. Develop a rationale for the chemical basis of stress and how it can affect homeostasis. Find out about the current research on aging and describe the effects of aging on the genetic material of the cell.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all of the chapter-specific online media resources for Chapter 1 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 1.1 General description of anatomy and physiology (pp. 2 and 3) Section 1.2 Levels of structural organization (pp. 3 and 4) Section 1.3 Life support (pp. 4 and 8)

Copyright © 2010 Pearson Education, Inc.

7

8

Text and Media Human Anatomy and Physiology Teacher's Guide Memory Game: Major Body Systems Section 1.4 Homeostasis (pp. 8–11) MP3 Tutor Session: Homeostasis Labeled Art: Interaction Between Elements of a Homeostatic Control System (Fig. 1.4, p. 9) Section 1.5 The Language of Anatomy (pp. 11-20) Art Labeling: Regional terms used to designate specific areas of the body (Fig. 1.7a, p. 13) Art Labeling: Regional terms used to designate specific areas of the body (Fig. 1.7b, p. 13 ) Artist labeling: dorsal and ventral body cavities and their subdivisions (Fig. 1.9, p. 16) Memory game: Main body cavities Chapter summary Crossword puzzle 1.1 Crossword puzzle 1.2 Web links Chapter quiz Art labeling quiz Multiple matching quiz Selection quiz True or false quiz Chapter Practice Test Study Tools Histology Atlas myeBook Flashcards Glossary O

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1. Systems Working Together (WNS; 15 min, 1993). Animations, X-rays, films and microscopic images help to explain how the human body works. Students learn that some organs belong to more than one system and that all systems must work together to support all of their activities. 2. The Incredible Human Machine (CBS; 60 min., 1992). Sophisticated photographic techniques reveal the wonders of the body's inner world. 3. The Inner Universe (PBS; 60 min., 1995). NOVA takes viewers on an incredible journey into the micro-world of the human body. Using 3-D computer animation and recordings of microscopic events, this program follows the functions of the human muscular, immune, digestive, and reproductive systems. Interviews and images showing four famous athletes in action demonstrate the connections between inner function and outer physical performance and health. Copyright © 2010 Pearson Education, Inc.

Chapter 1

The human body: an orientation

Software 1. A.D.A.M.® Interactive Anatomy® 4.0 (ADAM, BC; Win/Mac). The comprehensive, accurate, and anatomically correct database of the human body offers the student the opportunity to explore human systems and structures in the context of the entire body. 2. A.D.A.M.® MediaPro (ADAM, BC; Win/Mac). Provides clinical illustrations for resumes and classroom presentations. Contains more than 2000 images in JPEG format. 3. Practice Anatomy Lab™ 2.0 (PAL) (BC; Win/Mac). A comprehensive, interactive laboratory examination and evaluation tool that gives students 24/7 access to a variety of anatomical laboratory specimens, including human cadavers, anatomical models, histology slides, fetal sections and pig fetal sections. Each module includes a self-assessment with built-in audio pronunciation of key terms, plus graded practice tests and practice lab exams. The PAL 2.0 Instructor Resource DVD includes hundreds of editable images in PowerPoint® and JPEG formats and a customizable test database of over 1,800 questions. 4. The Ultimate Human Body, version 2.2 (AS; Win/Mac). A combination of illustrations, animations and microphotographs makes the complex systems of the human body accessible to the students. A "body scanner" provides students with an interactive, hands-on approach to lean while scanning a skeleton, view organs from multiple angles, and overlay one of 10 body systems. 5. WARD's Radiographic Anatomy: Image Gallery CD-ROM (WNS; Windows). This CD contains an extensive collection of images ideal for university level study. Includes X-rays, angiograms, CT scans, MRIs, and urograms. Each image is accompanied by descriptive text and identification tags. The CD also includes a variety of test methods.

Material to improve the lesson Thumbnails of all illustrations in Chapter 1 can be found in Appendix B.

Index Instructor Slide/Resource DVD Image Image Image Image Image Image

1,1 1,2 1,3 1,4 1,5 1,6

Figure 1.7 Figure 1.8 Figure 1.9 Figure 1.10 Figure 1.11 Figure 1.12 Table 1.1 A closer look

Structural organizational levels. Examples of connections between the organ systems of the body. The organ systems of the body and their main functions. Interaction between elements of a homeostatic control system. Regulation of body temperature through a negative feedback mechanism. Summary of the positive feedback mechanism that regulates platelet clot formation. Regional terms used to designate specific areas of the body. Body plans with associated magnetic resonance imaging (MRI). Dorsal and ventral body cavities and their subdivisions. Relationships of Serous Skins. The four abdominal and pelvic quadrants. The nine abdominal and pelvic regions. Guidelines and guiding terms Medical imaging: Illuminating the body

Copyright © 2010 Pearson Education, Inc.

9

10

Text and media guide to human anatomy and physiology

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 11. Since function (physiology) reflects structure, structure will determine and/or affect function. (p. 3) 12. See Figure 1.3 for a summary of all the organ systems of the body. 13. Nutrients: chemicals used for energy and cell formation; Oxygen: used in reactions that produce cellular energy; Water - the necessary liquid environment for all chemical reactions; Body temperature: to maintain the right temperature for chemical reactions; and atmospheric pressure – for gas exchange to take place. (p. 8) 14. It is the ability to maintain relatively stable internal conditions even in the face of constant changes in the external world. (p. 8) 15. Negative feedback mechanisms work in the opposite direction to diminish the original stimulus and/or reduce its effect, bringing the system back to normal. Examples are the regulation of body temperature and blood sugar levels. (pp. 9-10) Positive feedback mechanisms work in the same direction to reinforce the original stimulus and accelerate activity. Examples are blood clotting regulations and increased labour. (p. 10 and 11) 16. The anatomical position requires the body to be erect, arms hanging at the sides, palms facing forward, thumbs up, and feet flat on the floor. It is necessary to use this default position because most directional terms refer to the body in this position, regardless of its actual position. Using anatomical terms saves much description and is less ambiguous. (p. 13) 17. A plane refers to an imaginary line and a section refers to a section along that imaginary line. (p. 14) 18. a. Arm—Brachialis b. Thigh - femoral c. breast – breast d. Fingers/Toes - Digits e. Anterior Aspect of the Knee - Patella (p. 13) 19. The olecranon region of the elbow lies proximal (superior) and posterior (dorsal) to the palm. (pp. 12-13) 20. See Figs. 1.11 and 1.12. The figures illustrate the regions and quadrants and list several organs in each.

Critical Thinking Problems and Clinical Application 1. a. Parietal and/or visceral pleural membranes. B. The membranes allow the organs to slide easily along the walls of the cavity and over one another without friction. C. Organs and membranes stick and rub against each other, causing friction, heat, and pain. (p. 16 and 17) 2. a. anterior aspect of elbow b. took off his shirt c. Buttocks (p. 13)

Copyright © 2010 Pearson Education, Inc.

Chapter 1

The human body: an orientation

3. Of the procedures listed, MRI would be the best option as dense structures (e.g. skull) do not interfere with vision with this technique and are better suited to produce a high-resolution view of soft tissues, particularly nerve tissue. In addition, MRI can provide information about the chemical state of a tissue. So once the suspected tumor is located, magnetic resonance can perform a "metabolic biopsy" to determine if it is cancer. 🇧🇷 🇧🇷 all this without surgery. (pp. 18-19) 4. This is an example of a negative feedback mechanism. The first stimulus is the drop in calcium in the blood. This drop in blood calcium causes the release of PTH, which triggers bone breakdown, releases calcium into the blood, and increases blood calcium levels. The original downward trend in calcium has been halted and reversed. 5. The carpal region is at the wrist. (Page 13)

Suggested Reading Hazen, Robert. "What is life?" New Scientist 192 (November 2006): 46-51. Lester, David S. and Olds, James L. "Biomedical Imaging: 2001 and Beyond." The Anatomical Record 265 (2001): 35–36. Morris, D. The Naked Ape: A Zoological Study of the Human Animal. New York: Dell Publishing Co., 1999. Sivitz, Laura B. "Beyond Imaging". Science News 159 (January 2001): 12-13. Watch out Matthew. “Using nature as a design guide”. Business Week Online (February 2008): http://www.businessweek.com/innovate/content/feb2008/id20080211_074559.htm. Weiss, Pedro. "Magnetic Whisper". Science News 159 (January 2001): 42-44. Yonas, H., D.W. Johnson, and R.R. Pindzola. "Xenon-enhanced CT of cerebral blood flow". Scientific American (September/October 1995): 58-67.

Copyright © 2010 Pearson Education, Inc.

11

2

Chemistry comes alive

Goals

Chemical reaction

PART 1: CHEMISTRY FUNDAMENTALS Definition of Terms: Matter and Energy 1. Distinguish between matter and energy and between potential and kinetic energy. 2. Describe the most important forms of energy. Composition of Matter: Atoms and Elements 3. Define chemical elements and list the four elements that make up most of the matter in the body. 4. Define atom. List the subatomic particles; describe their relative masses, charges and positions in the atom. 5. Define atomic number, atomic mass, atomic weight, isotope and radioisotope. How matter is combined: molecules and mixtures 6. Define a molecule and distinguish a compound from a mixture. 7. Compare solutions, colloids and suspensions. Chemical Bonds 8. Explain the role of electrons in chemical bonds and in relation to the octet rule. 9. Distinguish between ionic, covalent and hydrogen bonds. 10. Compare and contrast polar and non-polar compounds.

11. Define the three main types of chemical reactions: synthesis, decomposition and exchange. Comment on the nature of oxidation-reduction reactions and their importance. 12. Explain why chemical reactions in the body are usually irreversible. 13. Describe the factors that affect the rate of chemical reactions. PART 2: BIOCHEMISTRY Inorganic Compounds 14. Explain the importance of water and salts in body homeostasis. 15. Define acid and base and explain the concept of pH. Organic compounds 16. Describe and compare the basic components, general structures and biological functions of carbohydrates and lipids. 17. Explain the role of synthesis and dehydration hydrolysis in the formation and degradation of organic molecules. 18. Describe the four levels of protein structure. 19. Name the function of molecular chaperones. 20. Describe the effect of the enzyme. 21. Compare and contrast DNA and RNA. 22. Explain the role of ATP in cell metabolism.

12 Copyright © 2010 Pearson Education, Inc.

Episode 2

Chemistry comes alive

Suggested Lesson Plan PART 1: CHEMISTRY FUNDAMENTALS I. Defining Terms: Matter and Energy (pp. 24-25) A. Matter is anything that occupies space and has mass (p. 24). 1. Mass is equal to the amount of matter in the object. 2. Mass remains constant regardless of gravity. B. States of Matter (p. 24) 1. Matter exists in one of three states: solid, liquid or gas. C. Energy (pp. 24-25) 1. Energy is the ability to do work and exists in two forms. a. Kinetic energy is the energy of motion. B. Potential energy is stored energy. 2. Forms of energy a. Chemical energy is the energy stored in chemical bonds. B. Electrical energy results from the motion of charged particles. C. Mechanical energy is the energy directly related to matter in motion. i.e. Radiant energy is energy that propagates in waves. 3. Energy is easily transformed from one form to another.

II. Composition of matter: atoms and elements (p. 25-28; Fig. 2.1-2.3; Tab. 2.1) A. Basic terms (p. 25; Tab. 2.1) 1. Elements are individual substances that cannot be broken down more easily into substances dismantle usual chemical means. 2. Four elements: carbon, hydrogen, oxygen and nitrogen make up about 96% of body weight. 3. Atoms are the smallest particles of an element that retain the properties of that element. 4. Elements are denoted by a one or two letter abbreviation called the atomic symbol. B. Atomic Structure (pp. 25-27; Figures 2.1-2.2) 1. Every atom has a central nucleus with packed protons and neutrons. a. Protons have a positive charge and weigh 1 atomic mass unit (one). B. Neutrons have no charge and weigh 1 amu. 2. Electrons move around the nucleus, have a negative charge and are weightless (0 amu). 3. Atoms are electrically neutral and the number of electrons equals the number of protons. 4. The planetary model is a simplified two-dimensional model of atomic structure. 5. The orbital model is a more accurate three-dimensional model that speaks of orbital regions rather than specific orbital patterns. C. Identify Elements (pp. 27-28; Figure 2.3) 1. Elements are identified by their number of protons, neutrons and electrons.

Copyright © 2010 Pearson Education, Inc.

13

14

Text and Media Human Anatomy and Physiology Teacher Guide 2. The atomic number of an element is equal to the number of protons in an element. a. Since the number of protons equals the number of electrons, the atomic number indirectly indicates the number of electrons. 3. The mass number of an element is equal to the number of protons plus the number of neutrons. a. The electron has no weight and is ignored in the calculation of the mass number. 4. Isotopes are structural variants of an atom that have the same number of protons but differ in the number of neutrons. 5. Atomic weight is an average of the relative weights of all known isotopes of an element, taking into account their relative abundance in nature. 6. Radioisotopes are heavier, more unstable isotopes of an element that spontaneously decay into more stable forms. a. The time it takes for a radioisotope to lose half of its radioactivity is called its half-life.

3. How Matter Combines: Molecules and Compounds (pp. 28-30; Fig. 2.4) A. Molecules and Compounds (pp. 28-29) 1. A combination of two or more atoms is called a molecule. 2. When two or more atoms of the same element combine, it is called a molecule of that element. 3. When two or more atoms of different elements are combined, it is called a molecule of a compound. B. Mixtures (pp. 29 and 30; Figure 2.4) 1. Mixtures are substances consisting of two or more physically mixed components. 2. Solutions are homogeneous mixtures of compounds that can be gases, liquids, or solids. a. The substance present in the largest amount is called the solvent. B. Substances that are present in smaller amounts are referred to as solutes. C. Solutions can be described by their concentrations. These can be expressed in percent or in molarity. 3. Colloids or emulsions are heterogeneous mixtures, generally milky in appearance, with larger solute particles that do not separate from solution. 4. Suspensions are heterogeneous mixtures with large, often visible, solutes that tend to settle. C. Distinguishing between mixtures and compounds (p. 30) 1. The main difference between mixtures and compounds is that there are no chemical bonds between the molecules of a mixture. 2. Mixtures can be physically separated into their chemical components; The separation of compounds takes place chemically. 3. Some mixtures are homogeneous, others heterogeneous.

4. Chemical Bonds (pp. 31-35; Figs. 2.5-2.10) A. A chemical bond is an energy relationship between the electrons of reacting atoms (p. 31; Fig. 2.5). 1. The Role of Electrons in Chemical Bonding a. Electrons occupy spatial regions, so-called electron shells, which surround the shell core. Copyright © 2010 Pearson Education, Inc.

Episode 2

Chemistry comes alive

B. Each electron shell represents a different energy level. C. Each electron shell contains a certain number of electrons, and the shells tend to fill sequentially from closest to the nucleus to farthest. i.e. The octet rule, or rule of eight, states that atoms with the exception of the first energy shell (stable with two electrons) are stable with eight electrons in their outermost (valence) shell. B. Types of Chemical Bonds (pp. 32–35; Figures 2.6–2.10) 1. Ionic bonds are chemical bonds between two atoms that transfer one or more electrons from one atom to the other. a. Ions are charged particles. B. An anion is an electron acceptor that carries a net negative charge due to the extra electron. C. A cation is an electron donor that carries a net positive charge due to the loss of an electron. i.e. Crystals are large structures of cations and anions held together by ionic bonds. 2. Covalent bonds are formed when two atoms share electrons. a. Some atoms can share two or three electrons, resulting in double or triple covalent bonds. B. Non-polar molecules share their electrons equally between two atoms. C. In polar molecules, electrons spend more time around one atom, causing that atom to become partially negatively charged while the other atom is partially positively charged. i.e. A polar molecule is often called a dipole because of the two poles of charge that the molecule contains. 3. Hydrogen bonds are weak attractive forces that form between partially charged atoms found in polar molecules. a. Surface tension is caused by hydrogen bonds between water molecules. B. Intramolecular bonds can form between partially charged atoms in a large molecule and are important in maintaining the shape of that molecule.

V. Chemical Reactions (pp. 35-38; Fig. 2.11) A. Chemical Reactions (pp. 35-36) 1. Chemical reactions occur whenever bonds are formed, rearranged, or broken. 2. Chemical Equations a. A chemical equation describes what happens in a reaction. B. Chemical reactions denote the types and numbers of reacting substances, called reactants; the chemical composition of the products; and the relative proportion of each reactant and product, if balanced. B. Patterns of chemical reactions (pp. 36-37; Fig. 2.11) 1. In a synthesis (joining) reaction, larger molecules are made from smaller molecules. 2. In a decomposition reaction, a molecule is broken down into smaller molecules. 3. Exchange (displacement) reactions include synthesis and decomposition reactions. 4. Oxidation-reduction reactions are special exchange reactions in which electrons are exchanged between reactants.

Copyright © 2010 Pearson Education, Inc.

fifteen

sixteen

Text and Media Human Anatomy and Physiology - Teacher's Guide C. Energy Flow in Chemical Reactions (p. 37) 1. Exergonic reactions release energy as a product, while endergonic reactions absorb energy. D. Reversibility of chemical reactions (p. 37) 1. All chemical reactions are theoretically reversible. 2. When the rate of the forward reaction equals the rate of the reverse reaction, the reactions have reached chemical equilibrium. E. Factors Affecting the Rate of Chemical Reactions (pp. 37-38) 1. Chemicals react when they collide with enough force to overcome the repulsion of their electrons. 2. An increase in temperature increases the rate of a chemical reaction. 3. Smaller particle size leads to faster reaction speed. 4. Higher reagent concentration leads to faster reaction speed. 5. Catalysts speed up a chemical reaction without taking part in the reaction.

PART 2: BIOCHEMISTRY VI. Inorganic Compounds (pp. 38 and 41; Figs. 2.12 and 2.13) A. Water (pp. 38 and 39) 1. Water is the most important inorganic molecule, accounting for 60 to 80% of the volume of most living cells. 2. Water has a high heat capacity, which means it absorbs and releases a lot of heat before changing temperature. 3. Water has a high heat of vaporization, which means it takes a lot of energy (heat) to break the bonds between the water molecules. 4. Water is a polar molecule and is called the universal solvent. 5. Water is an important reactant in many chemical reactions. 6. Water forms a protective cushion around the body's organs. B. Salts (p. 39; Fig. 2.12) 1. Salts are ionic compounds containing cations other than H and anions other than the hydroxyl ion (OH). 2. When salts dissolve in water, they dissociate into their ionic components. C. Acids and Bases (pp. 39-41; Fig. 2.13) 1. Acids are also known as proton donors and dissociate in water to form hydrogen ions and anions. 2. Bases are also called proton acceptors and accept hydrogen ions. 3. The relative concentration of hydrogen ions is measured in units of concentration called pH units. a. The higher the concentration of hydrogen ions in a solution, the more acidic the solution is. B. The higher the concentration of hydroxyl ions, the more basic or alkaline the solution. C. The pH scale goes from 0 to 14. A pH of 7 is neutral; a pH below 7 is acidic; a pH above 7 is basic or alkaline. 4. Neutralization occurs when an acid and a base are mixed. They react with each other in crowding reactions to form a salt and water. 5. Buffers resist large pH swings that would be harmful to living tissue.

Copyright © 2010 Pearson Education, Inc.

Episode 2

Chemistry comes alive

VIII. Organic Compounds (pp. 42-56; Figures 2.14-2.24; Tables 2.2-2.4) A. Carbohydrates, lipids, proteins, and nucleic acids are molecules unique to living systems, and all contain carbon, leading them to organic compounds (p. 42) . ). B. Carbohydrates (p. 43; Figs. 2.14 and 2.15) 1. Carbohydrates are a group of molecules that include sugars and starches. 2. Carbohydrates contain carbon, hydrogen and oxygen. 3. The main function of carbohydrates in the body is to provide cellular fuel. 4. Monosaccharides are simple sugars that are single chain or single ring structures. 5. Disaccharides are formed when two monosaccharides are joined by dehydration synthesis. 6. Polysaccharides are long chains of monosaccharides linked together by synthesis through dehydration. C. Lipids (pp. 43–47; Fig. 2.16; Table 2.2) 1. Lipids are insoluble in water but readily soluble in non-polar solvents. 2. Triglycerides (neutral fats) are commonly referred to as fats when solid and oils when liquid. 3. Phospholipids are diglycerides with a phosphorus group and two fatty acid chains. 4.Steroids are planar molecules composed of four hydrocarbon rings joined together. 5. Eicosanoids are a group of different lipids derived from arachidonic acid. D. Proteins (pp. 47-53; Fig. 2.17-2.21; Table 2.3) 1. Proteins make up 10-30% of cell mass. a. They are the basic structural material of the body. B. They also play an important role in cell function. 2. Proteins are long chains of amino acids connected by peptide bonds. 3. Proteins can be described in terms of four levels of structure. a. The linear sequence of amino acids is the primary structure. B. Proteins twist and turn on themselves to form a more complex secondary structure. C. A more complex structure is tertiary structure, which results from the folding of the protein onto itself to form a sphere-like structure. i.e. The quaternary structure results from two or more polypeptide chains grouped together to form a complex protein. 4. Fibrous and Globular Proteins a. Fibrous proteins stretch and are thread-like. They are known as structural proteins and most only have secondary structure. B. Globular proteins are compact spherical structures. They are chemically active molecules, water soluble and play an important role in the vital functions of the organism. C. Fibrous proteins are stable, but globular proteins are prone to denaturation and lose shape due to the breaking of their hydrogen bonds. 5. Protein denaturation is a loss of the specific three-dimensional structure of a protein. It can occur when globular proteins undergo a variety of chemical and physical changes in their environment. 6. Molecular chaperones or chaperonins are a type of globular protein that helps proteins achieve their three-dimensional shape.

Copyright © 2010 Pearson Education, Inc.

17

18

Text and Media Human Anatomy and Physiology Teacher's Guide 7. Enzymes and Enzyme Activity a. Enzymes are globular proteins that act as biological catalysts. B. Enzymes can be pure proteins or consist of two parts, collectively called a holoenzyme. C. Each enzyme is chemically specific. i.e. Enzymes work by lowering the activation energy of a reaction. E. Nucleic Acids (DNA and RNA) (pp. 53-55; Figure 2.22; Table 2.4) 1. Nucleic acids, composed of carbon, oxygen, hydrogen, nitrogen and phosphorus, are the largest molecules in the body. 2. Nucleotides are the structural units of nucleic acids. 3. Each nucleotide consists of three components: a pentose sugar, a phosphate group, and a nitrogenous base. 4. Five nitrogenous bases are used in nucleic acids: adenine (A), guanine (G), cytosine (C), uracil (U), and thymine (T). 5. DNA or Deoxyribonucleic Acid a. DNA is the cell's genetic material and is located in the cell's nucleus. B. DNA is replicated before cells divide and provides instructions for making all of the proteins found in the body. C. The structure of DNA is a double-stranded polymer containing the nitrogenous bases A, T, G and C and the sugar deoxyribose. i.e. The binding of nitrogenous bases in DNA is highly specific; A binds to T and G binds to C. e. Bases that always bind are called complementary bases.

F.

6. RNA or Ribonucleic Acid a. RNA resides outside of the cell nucleus and is used to make proteins according to DNA's instructions. B. The structure of RNA is a single-stranded polymer containing the nitrogenous bases A, G, C, and U and the sugar ribose. C. In RNA, G binds to C and A to U. ATP or adenosine triphosphate (pp. 55-56; Fig. 2.23-2.24) 1. ATP is the energy currency used by the cell. 2. ATP is an RNA nucleotide that contains adenine and has two additional phosphate groups attached to it. 3. The additional phosphate groups are linked by high-energy bonds. 4. Breaking high-energy bonds releases energy that the cell can use to do its work.

Cross-references For more information on the topics discussed in Chapter 2, see the chapters listed below. 1. Chapter 3: Phospholipids in the composition and structure of membranes; DNA replication and role of DNA and RNA in protein synthesis; cell ions; enzymes and proteins in cell structure and function; Hydrogen Bonds 2. Chapter 9: Role of ATP in Muscle Contraction; Role of Ions in Muscle Cell Contraction 3. Chapter 11: ATP, Ions and Enzymes in Nerve Impulse 4. Chapter 16: Steroid-Based Hormones and Amino Acids 5. Chapter 22: Acid-Base Balance Copyright © 2010 Pearson Education, Inc. .

Episode 2

Chemistry comes alive

6. Chapter 23: Function of Digestive Enzymes; acid function of the digestive system; Digestion of Proteins, Carbohydrates and Lipids 7. Chapter 24: Oxidation-Reduction Reaction; Importance of ions (minerals) in vital processes; carbohydrate, fat and protein metabolism; Examples of the Basic Chemistry of Life 8. Chapter 25: Kidney Electrolyte Control 9. Chapter 26: Acid-Base Balance, Electrolytes and Buffers; Sodium and Sodium and Potassium Pump 10. Appendix E: Periodic Table of the Elements

Teaching Tips 1. Introduction to Chemistry for Biology Students, 9th Edition, by George Sackheim, is an excellent resource for students who need a quick refresher on chemistry or for those who need a little extra help. The book is designed as an individualized learning companion. Most students should be able to complete a review of Marieb's Chapter 2 Basics in about 2-6 hours. 2. As an alternative to presenting chemistry in Chapter 2 as a separate block of material, you can cover the topics at the bare minimum at this point and expand on the topics later as areas of application are discussed. 3. Students often find the concept of isotopes confusing. A clear distinction between atomic mass and atomic weight helps clarify the problem. 4. When discussing radioisotopes, it may be helpful to refer students to the discussion of PET scans in Chapter 1 under “A Closer Look”. 5. Redox reactions involve the loss and gain of electrons. The oxidized reactant loses electrons while the reduced reactant gains electrons. An easy way to remember this is the phrase "Leo the lion going ger". Leo means "electron loss is oxidation" and ger means "electron gain is reduction". 6. In biological oxidation-reduction reactions, the donation and acceptance of electrons is often associated with the donation and acceptance of hydrogen atoms. Electrons are still transferred because the hydrogen atom contains an electron. 7. The relationship between the terms catalyst and enzyme can be illustrated by asking students if all enzymes are catalysts and if all catalysts are enzymes. 8. Table 2.4 is an excellent summary of the differences between DNA and RNA. This information is important when discussing protein synthesis. 9. The notion that ATP is the cell's "energy currency" should be emphasized. Students must realize that without ATP, molecules cannot be synthesized or broken down, cells cannot hold boundaries, and life processes cease. 10. Alternating between ATP and ADP is a simple but important concept that is often overlooked by students.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Obtain and/or create three-dimensional models of different types of biological molecules such as glucose, DNA, proteins and lipids. 3. Carry materials or items composed of common elements, e.g. B. gold chain, coal, copper pipe, cast iron. Also give examples of common compounds such as water, table salt, vinegar and baking soda. Ask for definitions of atoms, elements, and compounds, and an explanation of how an atom and a molecule of a compound differ. Copyright © 2010 Pearson Education, Inc.

19

20

Text and Media Human Anatomy and Physiology – A Guide for Teachers 4. Ask students to name any foods that contain saturated fat and any foods that contain unsaturated fat that they have eaten in the past 24 hours. 5. Obtain a two foot piece of heavy gauge rope or twine. Spin slowly to view the primary, secondary, and tertiary levels of protein organization. 6. Obtain a Thompson style vacuum tube with a frosted inner plate (to show the electrons), a DC generator (Tesla coil) and a bar magnet. Turn off the lights in the room and charge one end of the tube to start a beam of electrons. Use a magnet to move the electron beam up and down. This experiment helps visualize electrons as particles. 7. Obtain an electrolyte test system (lamp assembly with electrodes connected) and prepare a range of solutions such as salt, acid, base, glucose, etc. Place electrodes in solutions to illustrate the concept of electrolytes. 8. Prepare two true solutions (1% sodium chloride, 1% glucose) and two colloidal solutions (1% cooked starch, sol state; gelatin, gel state). Turn off the lights in the room and shine a beam of light through each light to demonstrate the Tyndall effect of colloids. 9. Get two different strands of pop-it beads. Bring the spheres together to demonstrate a synthesis reaction and separate them to demonstrate a decomposition reaction. Take a bead from each chain and join them together to illustrate an exchange reaction. 10. Use a slinky to demonstrate the denaturation of an enzyme. Tie the colored string to the slinky in two widely spaced places, then make a loop and twist the slinky on itself to bring the two pieces of string closer together. Identify the position of the cable pieces as the active position. Then remind the students that when the hydrogen bonds that hold the enzyme (or structural protein) in its specific 3D structure are broken, the active site (or structural protein) is destroyed. Unroll the slinky to illustrate this point.

Critical Thinking/Discussion Points 1. Discuss how two polysaccharides, starch and cellulose, each having the same subunit (glucose), have vastly different properties. Why can we digest starch but not cellulose? 2. How and why do virtually all organisms (plants, animals, and bacteria) use the exact same energy molecule, ATP? 3. How can a substance like alcohol be a solvent under one condition and a solute under another? Give examples of solid, liquid and gaseous solutions. 4. Describe how weak bonds can hold large macromolecules together. 5. Why can we say that most of matter, like the table you write on, is actually empty space? 6. When driving through the garage at night you will see the headlights on the garage door but not in the air between the car and the door. There? What would be observed if the night were cloudy? 7. Why are the water molecules on the surface of a water droplet closer together than those inside?

Library Research Topics 1. Investigation of the use of radioisotopes in the treatment of cancer. 2. Study the mechanisms by which DNA can repair itself. 3. Find Niels Bohr's studies on the structure of atoms and the position of electrons. Discover why your work with hydrogen gas formed the basis of our knowledge of matter. Copyright © 2010 Pearson Education, Inc.

Episode 2

Chemistry comes alive

4. How can a donut give us so much "energy"? Find out where exactly this energy comes from. 5. All members of the "cellular" world have used phospholipids to build cell membranes. What special properties do these molecules have to explain this phenomenon? 6. What problems are associated with trans fats in the diet? How has awareness of these effects changed our eating habits? 7. Virtually every time an amino acid chain made up of all 20 amino acids is formed in the cell, it twists into an alpha helix and then folds back into a ball. There? 8. What scientific advances resulted from the sequencing of the human gem (Human Genome Project)? 9. What is a DNA fingerprint? Discover the applications of this technology.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all of the chapter-specific online media resources for Chapter 2 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives PART 1: CHEMISTRY FUNDAMENTALS Section 2.1 Definition of Terms: Matter and Energy (pp. 24–25) Animation: Concepts of Energy Section 2.2 Composition of Matter: Atoms and Elements (pp. 25–28) Animation: Atomic Structure Section 2.3 How Matter Combines: Molecules and Mixtures (pp. 28–30) Section 2.4 Chemical Bonds (pp. 31–35) Section 2.5 Chemical Reactions (pp. 35–38) PART 2: BIOCHEMISTRY Section 2.6 Inorganic Compounds (pp. 38–41 ) MP3 Tutor Session: Inorganic Compounds Physiology® Interactive Systems Set of 10: Fluids and Electrolytes: Introduction to Body Fluids Section 2.7 Organic Compounds (pp. 42-56) Artist Tagged: Lipids (Fig. 2.16, p. 46 ) Artist Labeling: Mechanism of action of enzymes (Fig. 2.21, p. 53) Artist's caption: DNA structure (Fig. 2.22, p. 54) Memory game: important molecules Animation: disaccharides Animation: polysaccharides Animation: fats

Copyright © 2010 Pearson Education, Inc.

21

22

Text and Media Teacher's Guide to Human Anatomy and Physiology Animation: Protein Structure Animation: Primary and Secondary Structure Animation: Tertiary and Quaternary Structure Animation: How Enzymes Work Choice Quiz True or False Quiz Chapter Practice Test Learning Tools Histology Atlas myeBook Flashcards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1. Basic Chemistry for Biology Students (HRM; 21 min, 1993). Detailed animations of chemical models introduce students to chemical concepts important to understanding life processes. 2. Double Helix (FHS; 107 min, 1987). Excellent Hollywood-style film (starring Jeff Goldblum) that captures all the drama of the discovery of DNA. 3. Biochemistry I: Atoms, Ions and Molecules (CBS; 27 min). This DVD describes the basic structure of atoms and how ions are formed, as well as studying molecules and the covalent bonds that hold them together. The program also explains the difference between organic and inorganic molecules and polar and non-polar molecules. A look at the pH concept and the role of buffers completes the program. 4. Biochemistry II: Carbohydrates, Proteins, Lipids and Nucleic Acids (CBS; 36 min). This DVD explains how polymers are synthesized and discusses the functions of carbohydrates, lipids and proteins. The use of nucleic acids for information storage and energy transfer is also discussed.

Copyright © 2010 Pearson Education, Inc.

Episode 2

Chemistry comes alive

Software 1. Introduction to Chemistry: Interactive Student Tutorial, Fourth Edition (PH; Win/Mac). An interactive plugin that allows students to view or review key chemical concepts in a highly visual way and provides a hands-on self-assessment. It contains over a hundred animations, video clips of experimental demonstrations, simulations, 3D molecular models and much more.

Material to improve the lesson Thumbnails of all illustrations in Chapter 2 can be found in Appendix B.

Index Instructor Slide/Resource DVD Image Image Image Image Image Image Image

2,1 2,2 2,3 2,4 2,5 2,6 2,7 2,8

Figure 2.9 Figure Figure Figure Figure Figure

2,10 2,11 2,12 2,13 2,14

Figure Figure Figure Figure Figure

2,15 2,16 2,17 2,18 2,19 2,20

Figure 2.21 Figure 2.22 Figure 2.23 Figure 2.24 Table 2.1 Table 2.2 Table 2.3 Table 2.4

Two models of the structure of an atom. Atomic structure of the three smallest atoms. hydrogen isotopes. The three basic types of mixtures. Chemically inert and reactive elements. Formation of an ionic bond. Formation of covalent bonds. Carbon dioxide and water molecules have different shapes, as molecular models show. Ionic, polar, and nonpolar covalent bonds compared along a continuum. Hydrogen bonds between polar water molecules. Patterns of chemical reactions. Dissociation of salt in water. The pH scale and the pH values ​​of representative substances. Biological molecules are formed from their monomers or units by dehydration synthesis and broken down into monomers by hydrolysis reactions. Important carbohydrate molecules for the body. lipids. amino acid structures. Amino acids are linked by peptide bonds. levels of protein structure. Enzymes lower the activation energy required for a reaction to proceed quickly. enzymatic mechanism of action. Structure of DNA Structure of ATP (adenosine triphosphate). Three examples of cellular work fueled by ATP energy. Common elements that make up the human body. Representative lipids in the body. Representative types of proteins in the body. Comparison of DNA and RNA

Copyright © 2010 Pearson Education, Inc.

23

24

Text and media guide to human anatomy and physiology

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 23. Energy is defined as the ability to do work or to set matter in motion. Energy has no mass, takes up no space, and can only be measured by its effect on matter. Potential energy is the energy an object has due to its position relative to other objects. Kinetic energy is the energy associated with a moving object. (p. 24) 24. According to the first law of thermodynamics, energy can neither be created nor destroyed. The energy is not really lost, but can be released in another form, such as heat or light. In this way, the performance can become partially unusable. (p. 25) 25. a. Taxi. C, c. H, D. Speed. N, F.O, g. K, H. In (Appendix E) 26. a. All three are carbon with six protons. (p. 27) b. They all have different numbers of neutrons and therefore have different atomic masses. (p. 27) c. isotopes. (p. 27) d. See illustration. 2.5b, which provides a drawing of a planetary model. (p. 31) 27. a. Add the molecular weight of all the atoms: 9 12 (C) 8 1 (H) 4 16 (O) 180 g. B. The total molecular weight is the number of grams in a mole, in this case 180. c. Divide the number of grams in the bottle by the number of grams in one mole of aspirin. This equals the total number of moles in the bottle. i.e. Answer 2.5 Mol (p. 30) 28. a. covalent. B. covalently c. Ionic (pp. 32-33) 29. Hydrogen bonds are weak bonds formed when a hydrogen atom that is already covalently bonded to an electronegative atom is attracted to another electronegative atom. Hydrogen bonds often occur between water molecules, connecting large molecules like DNA and proteins into specific three-dimensional shapes. (p. 35) 30. a. The reversibility of the reaction can be indicated by double reaction arrows pointing in opposite directions. B. When the arrows are of equal length, the reaction is in equilibrium. C. Chemical equilibrium is reached when for every product molecule formed, one product molecule breaks down and the same reactants are released. (p. 37) 31. Primary structure - linear molecule composed of peptide bonds; second structure: winding of the primary structure into an alpha-helix or ß-folded sheet; Tertiary structure - helical coil folding. (pp. 48-50) 32. Dehydration refers to the joining of two molecules by the removal of water. Through this process, monosaccharides combine to form disaccharides and amino acids to form dipeptides (and proteins). Hydrolysis refers to the breaking down of a larger molecule, such as a disaccharide, into smaller molecules or monosaccharides by adding water to the bond that holds them together. (p. 42) 33. Enzymes lower the activation energy and reduce the randomness of reactions by reversibly binding to reactant molecules and holding them in the correct position(s) to interact. (p. 52) 34. Molecular chaperones are proteins that help fold other proteins into their functional three-dimensional structures. They also prevent misfolding. They are produced in large quantities when cells become damaged and proteins denature and need to be replaced. (pages 50 and 51)

Copyright © 2010 Pearson Education, Inc.

Episode 2

Chemistry comes alive

35. The surface tension of water causes the water molecules to assume a spherical shape, and because the glass does not completely overcome this attraction, the water can easily rise over the rim of the glass. (p. 35)

Critical Thinking Questions and Clinical Applications 1. In a freshwater lake, there are comparatively few electrolytes (salts) to direct current away from a swimmer's body. Therefore, the body would be a better conductor of electricity and the possibility of severe electrocution if lightning struck water is real. (p. 39) 2. a. Some antibiotics compete with the substrate at the enzyme's active site. This would tend to decrease the efficiency of the reaction. B. Since the bacterium would not be able to catalyze the essential chemical reactions normally caused by 'blocked' enzymes, the expected effect would be to inhibit their metabolic activities. This would allow the white blood cells to clear them out of the system. However, some human cells would also be affected and could, hopefully only temporarily, stop functioning as a result. (p. 52) 3. a. pH is defined as a measure of the concentration of hydrogen ions in a solution. The normal pH of blood is 7.4. B. Severe acidosis is critical because it can affect cell membranes, kidney function, muscle contraction, and neural activity. (pp. 40 and 41) 4. The pH of the blood rises and becomes more basic or alkaline. This is due to changes in the carbonic acid-bicarbonate buffer system in the blood. Hyperventilation leads to an increase in blood pH, which reduces the amount of carbonic acid in the blood. (p. 41) 5. Proteins in energy bars must undergo catabolic breakdown reactions, during which they are enzymatically broken down into individual amino acids. The resulting amino acids can be reassembled into structural or functional proteins via anabolic synthesis reactions. (p. 36)

Suggested Reading Ballew, et al. "Proteins folded in the act." Science 273 (July 1996): 29-30. Cech, TR "RNA as an enzyme". Scientific American 255 (November 1986): 64-75. Doolittle, RF "Proteins". Scientific American 253 (October 1985): 88-99. Dressler, DH and H. Potter. discover enzymes. New York: Scientific American Library, 1991. Gorman, Jessica. "Removing the thorn: biomaterials become more body-friendly." Science News 161(1) (January 2002): 13-14. Hartl, F.U. "Molecular Companions in Cellular Protein Folding." Nature 381 (June 1996): 571–580. Horgan, J. "In the Beginning." Scientific American 264 (February 1991): 116-125. Karplus, M. and JA McCammon. "Protein Dynamics". Scientific American 254 (April 1986): 42-51. Russo, S. and M. Plata. Introduction to chemistry: A conceptual approach. San Francisco: Benjamin Cummings, 2000. Ruvkun, Gary. "Insights into a Small RNA World". Science 294 (5543) (2001 Oct): 797-799. Welch, WJ "How cells respond to stress." Scientific American 268 (May 1993): 56.

Copyright © 2010 Pearson Education, Inc.

25

3

Cells: the living units

Objectives General description of the cellular foundations of life 1. Define cell. 2. Name the three main regions of a generalized cell and give their function. The plasma membrane: structure 3. Describe the chemical composition of the plasma membrane and relate it to the functions of the membrane. 4. Compare the structure and function of tight junctions, desmosomes, and gap junctions. The plasma membrane: membrane transport 5. Relate the structure of the plasma membrane to the mechanisms of active and passive transport. 6. Compare and contrast simple diffusion, facilitated diffusion, and osmosis in terms of substances transported, direction, and mechanism. 7. Distinguish between primary and secondary active transport. 8. Compare and contrast endocytosis and exocytosis in terms of function and direction. 9. Compare and contrast pinocytosis, phagocytosis and receptor-mediated endocytosis. 10. Define the membrane potential and explain how the resting membrane potential is established and maintained. The plasma membrane: interactions between cell and environment 11. Describe the function of the glycocalyx when cells interact with their environment.

12. Name different functions of membrane receptors and voltage-gated membrane channel proteins. The cytoplasm 13. Describe the composition of the cytosol. Define includes and list multiple types. 14. Discuss the structure and function of mitochondria. 15. Discuss the structure and function of the ribosomes, the endoplasmic reticulum and the Golgi apparatus, including the functional interrelationships between these organelles. 16. Compare the functions of lysosomes and peroxisomes. 17. Name and describe the structure and function of the elements of the cytoskeleton. 18. Describe the role of centrioles in mitosis and the formation of cilia and flagella. 19. Describe how the two main types of cell processes, cilia and microvilli, differ in structure and function. The nucleus 20. Describe the structure and function of the nuclear envelope, nucleolus and chromatin. Cell growth and reproduction 21. List the phases of the cell life cycle and describe the events in each phase. 22. Describe the process of DNA replication. 23. Define gene and genetic code and explain the function of genes. 24. Name the two phases of protein synthesis and describe the role of DNA, mRNA, tRNA and rRNA in each phase. 25. Compare triplets, codons and anticodons.

26 Copyright © 2010 Pearson Education, Inc.

Chapter 3 26. Describe the importance of ubiquitin-dependent degradation of soluble proteins. Extracellular materials 27. Name and describe the composition of extracellular materials.

Cells: the living units

Aspects of cell development 28. Discuss some theories about cell differentiation and aging. 29. Indicate the value of apoptosis for the organism.

Suggested Lesson Plan I. Overview of the cellular basis of life (pp. 62 and 63; Figs. 3.1 and 3.2) A. The four concepts of the state of cell theory (p. 62): 1. Cells They are the basic structural and functional units of the life. 2. The activity of an organism depends on the activity of its cells. 3. The biochemical activities of a cell are determined by its organelles. 4. The continuity of life has a cellular basis. B. Characteristics of Cells (p. 62; Figs. 3.1 and 3.2) 1. Cells vary greatly in size, shape and function. 2. All cells are mainly composed of carbon, hydrogen, nitrogen and oxygen. 3. All cells have the same basic parts and some common functions. 4. A generalized human cell contains the plasma membrane, cytoplasm and nucleus.

II. The plasma membrane: structure (pp. 63-67; Figs. 3.3-3.5) A. The liquid mosaic model (pp. 63-64; Figs. 3.3-3.4) 1. The plasma membrane consists of a bilayer of phospholipids, into which the minor Amounts of cholesterol and protein are included. 2. The phospholipid bilayer consists of two layers of phospholipids arranged tail to tail with their pole heads exposed to the water inside and outside the cell. 3. The inward and outward surfaces of the plasma membrane differ in the type and amount of lipids they contain. a. Glycolipids are found only in the outer membrane. B. Lipid rafts are also found only in the outer membrane and are thought to play a role in cell signaling. 4. Integral proteins are tightly embedded in the plasma membrane. a. Most integral proteins are transmembrane proteins that span the entire width of the membrane and are involved in transport as channels or transporters. 5. Peripheral proteins are not embedded in the plasma membrane but bound to integral proteins or phospholipids. a. Peripheral proteins can function as enzymes or in mechanical functions of the cell. 6. The glycocalyx is the flaky, sticky, carbohydrate-rich area that surrounds the cell. B. Membrane Contacts (pp. 66-67; Fig. 3.5) 1. Most cells in the body are held together by glycolipids, specialized cross-linking regions, or specialized membrane contacts. 2. Tight junctions are a type of membrane junction where integral proteins of neighboring cells fuse into a tight junction that prevents molecules from crossing the extracellular space between cells.

Copyright © 2010 Pearson Education, Inc.

27

28

Text and Media Human Anatomy and Physiology Teacher's Guide 3. Desmosomes are mechanical couplings scattered along the sides of neighboring cells that prevent their separation and reduce the likelihood of rupture when a tissue is stressed. 4. Gap junctions are communication links between cells that allow the passage of substances between neighboring cells.

3. The plasma membrane: membrane transport (pp. 68-77; Figs. 3.6-3.14; Tables 3.1-3.2) A. Passive processes do not use energy (ATP) to move substances down their concentration gradient (pp. 68-73; Figs. 3.6- 3.9; Table 3.1). 1. Diffusion is the movement of molecules along their concentration gradient. The diffusion rate is influenced by the molecule size and the temperature. 2. Simple diffusion is diffusion across the plasma membrane. 3. In facilitated diffusion, substances move across the plasma membrane by binding to transport proteins in the membrane or moving through channels. 4. Osmosis is the diffusion of water through a selectively permeable membrane. B. Active transport processes use energy (ATP) to move substances across a membrane (pp. 73–77; Figs. 3.10–3.14; Table 3.2). 1. Active transport uses solute pumps to move substances against a concentration gradient. The two types of active transport are primary active transport and secondary active transport. 2. Vesicular transport is the means by which large particles, macromolecules, and fluids are transported across the plasma membrane or into the cell. 3. Exocytosis is a process used to transport substances from inside the cell to the extracellular environment. 4. Endocytosis, transcytosis, and vesicle transport are vesicular transport processes that move molecules using protein-coated vesicles. 5. Clathrin-coated vesicles are the main pathway of endocytosis and transcytosis of bulk materials. 6. Non-clathrin-coated vesicles or caveolae are cavities in the cell membrane that encapsulate specific molecules in caveolin-coated, non-clathrin-coated vesicles.

4. The plasma membrane: generation of a resting membrane potential (pp. 77-79; Fig. 3.15) A. A membrane potential is a voltage across the cell membrane resulting from the separation of oppositely charged particles (ions) (p. 78). B. Resting membrane potential is a state in which the inside of the cell membrane is negatively charged relative to the outside and its potential is between 5 and 100 millivolts (p. 78; Fig. 3.15). 1. The resting membrane potential is mainly determined by the potassium (K) concentration gradient. 2. Active transport pumps ensure that passive ion movement does not result in electrochemical equilibrium across the membrane, thereby maintaining the membrane's resting potential.

Copyright © 2010 Pearson Education, Inc.

Chapter 3

Cells: the living units

V. The plasma membrane: cell-environment interactions (pp. 79-81; Fig. 3.16) A. Cells can interact directly with other cells, respond to extracellular chemicals, and interact with molecules that control migration (p. 79) . B. Functions of Cell Adhesion Molecules (pp. 79-81) 1. Cell adhesion molecules (CAMs) are glycoproteins that play a role in embryonic development, wound healing and immunity. C. Functions of Membrane Receptors (p. 81; Fig. 3.16) 1. Membrane receptors are integral proteins and glycoproteins that serve as binding sites. 2. Some membrane receptors act on contact signals, electrical signals, and chemical signals. D. Nitric oxide, composed of an oxygen atom and a nitrogen atom, is the first gas known to act as a biological messenger (p. 81).

SEEN. The cytoplasm (pp. 81-91; Figs. 3.17-3.28; Table 3.3) A. The cytoplasm is the cellular material between the cell membrane and the nucleus and is the site of greatest cellular activity (pp. 81-83). 1. There are three main elements of the cytoplasm: cytosol, cytoplasmic organelles and cytoplasmic inclusions. B. Cytoplasmic Organelles (pp. 83-89; Figs. 3.17-3.28; Table 3.3) 1. Mitochondria are sausage-shaped membranous organelles that are the cell's energy sources and produce most of its ATP. 2. Ribosomes are small coloring granules composed of protein and ribosomal RNA, which are the site of protein synthesis. 3. The endoplasmic reticulum is an extensive system of tubes and membranes enclosing fluid-filled cavities called cisternae that span the entire cytosol. a. The rough endoplasmic reticulum has ribosomes that make all of the proteins secreted by cells. B. The smooth ER is a continuation of the rough ER and consists of a circular network of tubules. Its enzymes catalyze reactions involved in various processes. 4. The Golgi apparatus is a series of flattened, stacked membrane sacs connected to clusters of membrane vesicles. a. The main function of the Golgi apparatus is to modify, concentrate and package the proteins and lipids produced in the rough ER. B. The Golgi apparatus creates vesicles that contain transmembrane lipids and proteins for incorporation into the cell membrane. C. The Golgi apparatus packages digestive enzymes into lysosomes. 5. Lysosomes are spherical membrane organelles that contain digestive enzymes. a. Lysosomes function best in acidic environments, can digest almost any type of biological molecule, and are rich in phagocytes. B. The lysosome membrane serves to allow the release of digestion products into the cytosol, but contains the acid hydrolases used to digest the molecules. 6. The endomembrane system includes the ER, the Golgi apparatus, secretory vesicles, lysosomes and the nuclear membrane.

Copyright © 2010 Pearson Education, Inc.

29

30

Text and media guide to human anatomy and physiology

7.

8.

9.

10

a. The endomembrane system works together to produce, store, and export biological molecules and to break down potentially harmful substances. Peroxisomes are membrane sacs that contain enzymes such as oxidases and catalases that serve to detoxify pollutants such as alcohol, formaldehyde, and free radicals. The cytoskeleton is a series of rods that traverse the cytosol, supporting cell structures and aiding in cell movement. a. There are three types of rods in the cytoskeleton: microtubules, microfilaments, and intermediate filaments. Centrosome and centrioles a. The centrosome is a region near the nucleus in which a group of microtubules are anchored. B. The centrosome functions as the organizing center for microtubules and forms the mitotic spindle during cell division. C. Centrioles are small, barrel-shaped organelles associated with the centrosome, which also form the bases of cilia and flagella. cell extensions a. Cilia are motile, whip-like extensions of cells on the exposed surfaces of some cells. B. Flagella are long cellular processes that move the cell through the environment. C. microvilli are finger-like extensions of the plasma membrane that increase in surface area.

VIII. The nucleus (pp. 91-95; Figs. 3.29-3.30) A. Basic characteristics (p. 91; Fig. 3.29) 1. The nucleus is the control center of the cell and contains the cellular DNA. 2. Most cells have a single nucleus, but very large cells can be multinucleated. 3. All cells in the body, except mature red blood cells, have a nucleus. 4. The nucleus is larger than the cytoplasmic organelles; It has three regions and subcompartments that contain proteins. B. Nuclear Envelope (pp. 91-93) 1. The nuclear envelope is a double membrane barrier that surrounds the nucleus. a. The outer membrane is continuous with the rough ER. B. The inner membrane is lined with a network of rigid protein filaments called nuclear laminae. 2. Nuclear pores invade areas where nuclear envelope membranes fuse at various sites. a. A protein complex, called the pore complex, lines each nuclear pore and regulates the passage of large particles in and out of the nucleus. 3. The nuclear envelope surrounds the liquid and solutes of the nucleus, the nucleoplasm. C. Nucleoli (p. 93) 1. Nucleoli are dark, spherical bodies within the nucleus. 2. There are usually one or two nucleoli per nucleus. 3. Nucleoli are the sites of assembly of ribosomal subunits and are large in actively growing cells.

Copyright © 2010 Pearson Education, Inc.

Chapter 3

Cells: the living units

D. Chromatin (pp. 93-95; Fig. 3.30) 1. Chromatin consists of about half DNA, the genetic material of the cell, and half histone proteins. 2. Nucleosomes are the basic unit of chromatin and are made up of groups of eight histone proteins linked by a DNA molecule. 3. As a cell prepares to divide, chromatin condenses into dense, rod-shaped chromosomes.

VIII. Cell growth and reproduction (pp. 95-107; Figs. 3.31-3.40) A. The cell life cycle (pp. 95-100; Figs. 3.31-3.33) 1. The cell life cycle is a series of changes that a undergoes through the Cell from the time it forms to the time it reproduces. 2. Interphase and cell division are the two main periods of the cell cycle. 3. Interphase is the period from cell formation to cell division and has three sub-phases. a. During the G1 subphase or gap 1, the cell is synthesizing proteins and actively growing. B. During the S phase, DNA is replicating. C. During G2 or interval 2, the subphase enzymes and other proteins are synthesized and distributed throughout the cell. i.e. DNA replication occurs when the DNA helix unwinds and the hydrogen bonds between its base pairs are broken. Each strand of nucleotides in DNA serves as a template for building a complementary strand of nucleotides. 4. Cell division is a necessary process for tissue growth and repair. There are three main events of cell division. a. Mitosis is the process of nuclear division in which cells contain all genes. B. Meiosis is the process of nuclear division found only in eggs and sperm, in which cells have half the genes found in other cells of the body. C. Cytokinesis is the process of division of the cytoplasm. i.e. The control of cell division depends on surface-volume relationships, chemical signaling, and contact inhibition. B. Protein Synthesis (pp. 100-107; Fig. 3.34-3.40) 1. DNA specifies the structure of protein molecules that act as structural or functional molecules. 2. Proteins are made up of polypeptide chains made up of amino acids. 3. Each gene is a segment of DNA that contains instructions for a polypeptide chain and exons that specify informative amino acid sequences and non-coding sequences called introns. 4. Each sequence of three nucleotide bases in DNA is called a triplet and specifies a specific amino acid. 5. The Role of RNA a. RNA exists in three forms that decode and execute DNA's instructions for protein synthesis: transfer RNA (tRNA), ribosomal RNA (rRNA), and messenger RNA (mRNA). B. All three types of RNA are incorporated into DNA in the nucleus and then released from the DNA to travel to the cytoplasm when the DNA returns to its original form.

Copyright © 2010 Pearson Education, Inc.

31

32

Text and Media Human Anatomy and Physiology - Teacher's Guide 6. There are two main steps in protein synthesis: transcription and translation. a. Transcription is the process of transferring base sequence information from a gene to a complementary mRNA molecule. ME. To make the mRNA complement, the transcription factor mediates the binding of RNA polymerase, an enzyme that controls mRNA synthesis. ii. The mRNA originally resulting from the transcription, the so-called primary transcript, contains introns that have to be removed. B. Translation is the process of converting the language of nucleic acids (nucleotides) into the language of proteins (amino acids). 7. Introns now appear to encode a variety of RNAs. a. Antisense RNAs made from the complementary strand of DNA can prevent translation of mRNA. B. Small RNAs called microRNAs can repress some mRNAs. C. Folded RNAs, called microswitches, can turn their own protein synthesis on or off in response to environmental changes.

IX. Extracellular Materials (p. 107) A. Extracellular materials are substances that contribute to body mass and are found outside of cells (p. 107). B. There are three classes of extracellular materials (p. 107). 1. Body fluids mainly consist of interstitial fluid, blood plasma and cerebrospinal fluid and are important for the transport and dissolution of solutes. 2. Cell secretions include substances that aid in digestion or act as a lubricant. 3. The extracellular matrix is ​​a gelatinous substance composed of proteins and polysaccharides.

X. Aspects of cell development (p. 108 and 109) A. Embryonic and fetal cell development (p. 108) 1. Embryonic cells are exposed to different chemical signals that cause them to take different pathways in their development. 2. Chemical signals influence development by turning genes on and off. 3. Cell differentiation is the process by which cells develop specific and distinctive properties. 4. Apoptosis is the programmed cell death of overgrown and stressed developing cells. B. Cellular Development in Adolescence (p. 108) 1. Most organ systems are well developed and functional before birth. 2. The body continues to make new cells throughout childhood and adolescence. 3. During early adulthood, the number of cells remains relatively constant, but local changes in the rate of cell division are common. C. Impact of Aging on Cells (pp. 108 and 109) 1. The attrition theory considers the cumulative effect of mild chemical damage and free radical production. 2. Cellular aging can also be due to autoimmune reactions and the progressive weakening of the immune response. 3. The genetic theory of cellular aging suggests that mitosis termination and cellular senescence are genetically programmed.

Copyright © 2010 Pearson Education, Inc.

Chapter 3

Cells: the living units

Cross-references For more information on the topics covered in Chapter 3, see the chapters listed below. 1. Chapter 2: Phospholipids; Kinetic energy; ions; adenosine triphosphate; Protein; enzymes; deoxyribonucleic acid; ribonucleic acid; Comparison of DNA and RNA; hydrogen bonding 2. Chapter 8: Lysosomal degradation (autolysis) and autodigestion of cells 3. Chapter 9: Role of the smooth ER in calcium ion storage and release; Microfilaments as contractile elements 4. Chapter 11: Special forms of cytoskeletal elements; membrane potentials of the nervous system 5. Chapter 14: Membrane receptors and functions in the autonomic nervous system 6. Chapter 18: Cell connections and cardiac function 7. Chapter 19: Cell connections and movement of substances through capillary walls 8. Chapter 21: Role of lysozyme in protecting the body; Role of the cilia in the body's innate defenses 9. Chapter 22: Diffusion of respiratory gases 10. Chapter 23: Microvilli and increased absorption area in epithelial cells of the small intestine; Membrane Transport Associated With Absorption Of Digested Substances 11. Chapter 24: Examples Of Membrane Transport 12. Chapter 25: Hydrostatic Pressure And Fluid Movement Across Membranes 13. Chapter 26: Membrane Transport Associated With Electrolyte Balance And Water 14. Chapter 27: Reproductive Cell Division And Production Of Gametes; tight junctions and the blood/testicle barrier; functions of flagella and cilia; Mitochondria and Energy Production in Sperm 15. Chapter 29: Cell Division in the Context of Heredity 16. Appendix C: mRNA Codons and the Amino Acids They Specify

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 3: The Microscope Exercise 4: The Cell - Anatomy and Division Exercise 5: The Cell - Cell Transport and Permeability Mechanisms PhysioEx™ 8.0 Exercise 5B: Cell Transport and Permeability Mechanisms: Computer Simulation 2. Marieb , IN. and S.J. mitchell Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 3: The Microscope Exercise 4: The Cell - Anatomy and Division Exercise 5: The Cell - Cell Transport and Permeability Mechanisms PhysioEx™ 8.0 Exercise 5B: Cell Transport and Permeability Mechanisms: Computer Simulation

Tips for Lesson 1. It is important to emphasize the distinction between passive and active processes. Copyright © 2010 Pearson Education, Inc.

33

34

Text and Media Human Anatomy and Physiology Teacher Guide 2. Students often compare bulk phase endocytosis to "drinker cells" and forget that the importance of the process is to absorb solutes in the liquid rather than the solvent itself. 3. The generation and maintenance of a resting membrane potential can be addressed now or postponed until the contraction of a skeletal muscle fiber is presented in Chapter 9. 4. Explain that the nuclear membrane is a double membrane and that each membrane is a phospholipid bilayer. Some students will equate phospholipid bilayer and double membrane. 5. As a survey method, cell organelles can be classified as membranous, microtubular, or “other”. 6. Clarify the difference between centrioles and centromeres. 7. Distinguish clearly between mitosis and cytokinesis. 8. To support the idea of ​​complementary base pairing, point out that cytosine and thymine are pyrimidines (single ring structures) and guanine and adenine are purines (double ring structures). For proper spacing, it is necessary to combine a purine with a pyrimidine for each rung of the DNA "ladder" (a rung three rings wide). Also show that adenine-thymine forms two hydrogen bonds and cytosine-guanine forms three hydrogen bonds. 9. Note the similarity of G and C so students can easily recall the complementary cytosine-guanine base pairing.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Assemble DNA and RNA models to illustrate complementary base pairing. 3. Extract DNA from a beaker of lysed bacterial cells using a glass rod to demonstrate the fibrillar nature of the molecule. 4. Use chromosome models with separable chromatids to illustrate mitotic phases. 5. Ask students to give examples of diffusion, osmosis, and filtration that are commonly encountered in everyday life. 6. Place a glass funnel with filter paper over a beaker. Illustrate how higher liquid pressure (provided by more liquid in the funnel) results in faster filtration. 7. Set up one or more of the following simple streaming demos: a. A few hours before class, place a large, histologically stained crystal in the center of an agar plate. A colored ring appears, radiating from the crystal. The whiteboard can be viewed on an overhead projector. B. Place a coloring crystal in a glass of water and display it on an overhead projector. This dramatic demonstration allows students to easily identify with the process involved. C. Use a bottle of perfume (or other substance) to illustrate distribution in the classroom. Do not promote its use until it is widely used. 8. A simple osmometer: Put a glucose solution in a dialysis bag and connect it tightly with a glass tube. Secure the tubing with a holder and clamp so that the dialysis bag is submerged in distilled water. Ask the students to observe the liquid level in the tube over time. 9. If you have a television camera/microscope system (or microprojector), set it up to show the effects of: (a) normal saline, (b) hypertonic saline, and (c) distilled water on red blood cells.

Copyright © 2010 Pearson Education, Inc.

Chapter 3

Cells: the living units

10. Use an animal cell model to demonstrate the different organelles and parts of the cell. 11. Use a set of transparencies or electron microscopy slides to visualize the subcellular organelles. 12. Use a hypothetical jelly salad to illustrate a cell. gelatin represents the cytosol; an orange represents the core; and nuts, raisins or other fruits are the various organelles. The container represents the plasma membrane.

Critical Thinking / Discussion Points 1. Cells tend to be relatively small and uniform in size. Why aren't cells bigger? Discuss your answer. 2. What are the advantages and disadvantages of asexual reproduction? Is mitosis a method of asexual reproduction? 3. What is the value of the start and end signals in the mRNA? 4. Why have certain body cells such as muscle and nerve cells "lost" their ability to divide? 5. Why must every daughter cell produced by mitosis have mitochondria? 6. Use the math equations to determine surface area and volume to show that volume increases faster than surface area. 7. Why is damage to the heart more serious than damage to the liver (or any other organ)? 8. Start with a cell containing 24 (or any hypothetical number) chromosomes and predict the number of chromosomes and chromatids present at each stage of mitosis. 9. Why is the precise division of chromosomes so important during mitosis? 10. What could be the evolutionary benefit of genetically programming cellular aging?

Library Research Topics 1. Receptor-mediated endocytosis is a highly selective mechanism of molecular uptake. How could it be used to kill cancer cells? 2. Why do we age? What seems to start the aging process? Do we have cellular mechanisms that control or facilitate this process? 3. Are all cancers caused by carcinogens? What other substances can cause cancer? 4. How can hybridomas aid investigative techniques and advance our understanding of the immune system? 5. Many genetic diseases are caused by mutations that change the sequence of nitrogen bases in DNA. How many codons are changed in sickle cell anemia? What amino acid does this mutation replace in hemoglobin? 6. In recent years, experimental fetal tissue implants have been used to treat brain disorders such as Parkinson's disease. What is the current status of such experiments? What are some of the moral, ethical, and legal concerns related to such experiments? 7. How has the advent of recombinant DNA techniques contributed to our understanding of proteins such as interferon, insulin, and interleukins? 8. Compare and differentiate prokaryotic and eukaryotic cells.

Copyright © 2010 Pearson Education, Inc.

35

36

Text and media guide to human anatomy and physiology

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all chapter-specific online media resources for Chapter 3 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 3.1 Overview of the cellular bases of life (pp. 62-63) Artist's caption: Structure of a generalized cell (Fig. 3.2, p. 63) Section 3.2 The plasma membrane: structure (pp. 63-67 ) Animation: Animation of the plasma membrane structure: Animation of Transport Proteins: Animation of Enzymes: Animation of Receptor Proteins: Animation of Structural Proteins: Animation of Tight Junctions: Animation of Desmosomes: Animation of Gap Junctions Section 3.3 The Plasma Membrane: Membrane Transport (p. 68 –77) MP3 Tutor Session: Membrane Transport Animation: Diffusion Animation: Osmosis Animation: Active Transport PhysioEx™ 8.0: Mechanisms of Cellular Transport and Permeability Section 3.4 The Plasma Membrane : Generation of a Resting Membrane Potential (pp. 77-79) Interactive Physiology ® 10-System Suite: Nervous System I: The Membrane Potential Section 3.5 The Membr Plasma Ana: Interactions between cell and environment (pp. 79–81) Animation: Signal transduction Sect itt 3.6 The cytopic mucus (p. 81-90) Animation: The endomembrane system Animation: Cilia and flagella Memory game: Cell organelles Section 3.7 The nucleus (pp. 90-92) Section 3.8 Cell growth and reproduction (pp. 92-107) Animation: DNA and RNA structure Animation: DNA -Replication Animation: Mitosis Animation: Cytokinesis Memory Game: Important Cellular Processes Section 3.9 Extracellular Materials (p. 107) Copyright © 2010 Pearson Education, Inc.

Chapter 3

Cells: the living units

Section 3.10 Aspects of Cell Development (pp. 108-109) Chapter Summary Crossword 3.1 Crossword 3.2 Crossword 3.3 Crossword 3.4 Web Links Chapter Quiz Art Labeling Quiz Matching Quiz Multiple Choice Quiz True-False Quiz Chapter Practice Quiz Learning Tools Histology Atlas myeBook Flashcards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Dias 1. Onion Mitosis (CBS) 35-mm-Dia-Set

Video 1. The Aging Process (ESF; 19 min., 1992). This show explains the effects of aging on the mind and body and explores theories about why cells wear out. 2. What is cancer? (ESF; 57 mins, 2004). Dartmouth-Hitchcock Medical Center Production provides an introduction to the development and growth of cancer. Featuring colorful animation and interviews with medical experts, the show explains the normal cellular behavior and etiology of cancer in a larger, dramatized story of a cancer patient undergoing diagnosis and treatment. 3. A journey through the cell (FHS; 25 min each, 1997). This two-volume set includes computer graphics and animation; includes presentations by scientists presenting ideas central to understanding cells. 4. Living Cells: Structure and Function (CBS; 36 min, 1996). This video introduces students to a variety of cell types and their structure and function. Real-time and time-lapse video microscopy provide a detailed view of subcellular components and key cellular activities such as mitosis and cell division. 5. Membranes and Transport (WNS; 24 min). How important is a membrane for a living cell? Answer this question by taking a deeper look at the cell's ability to regulate the movement of substances in, out, and around itself. Copyright © 2010 Pearson Education, Inc.

37

38

Text and media guide to human anatomy and physiology

Software 1. Carolina™ Basic Biology Cell Biology CD-ROM Set (CBS; Win/Mac). This 2-disc CD-ROM set provides the information needed to cover cell structure and function, as well as the concepts of mitosis and meiosis. 2. The Cell: Structure, Function and Process (HRM; Win/Mac). Introduces into the microscopic world of the cell and explores various cellular processes. 3. The Genetic Basis of Cancer (IM; Win/Mac). The CD-ROM, which focuses on breast and colon cancer, explores the genetic basis of cancer. 4. Inside the cell (CBS, CE; Win/Mac). 3D graphics illustrate cell organization and recent advances in cell biology. 5. Introduction to cells: the structure of the cell (IM; Win/Mac). Provides an introduction to the cell and describes the structure and function of the cell. 6. Osmosis Laboratory (IM; Win/Mac). He examines the control of osmosis for numerous variables and discusses hypertonic, hypotonic, and isotonic solutions. 7. The plasma membrane and cell transport (EC; Win/Mac). This CD offers a detailed study of cell membranes and motility. Introduces the liquid mosaic model. Students can explore cell biology at their own pace. 8. Practice Anatomy Lab™ 2.0: Histology (see full list on page 9 of this manual). 9. Mitosis and Meiosis CD-ROM by WARD (WNS; Win/Mac). This program contains illustrated basic information on mitosis and meiosis, detailed instructions on how to conduct examinations and a video presentation on meiosis. Laboratory activities can be performed in learn mode or test mode and include identification of mitotic stages and preparation of slides.

Materials to Improve Teaching Thumbnails of all illustrations in Chapter 3 can be found in Appendix B.

Transparency Index/Instructor Resource DVD figure figure figure figure figure figure figure figure figure figure figure figure figure figure figure figure figure

3,1 3,2 3,3 3,4 3,5 3,6 3,7 3,8 3,9 3,10 3,11 3,12 3,13 3,14 3,15 3,16 3, 17 3,18 3,19

cell diversity. Generalized cell structure. Structure of the plasma membrane according to the liquid mosaic model. Membrane proteins perform many jobs. cell junctions. Diffusion. Diffusion through the plasma membrane. Influence of membrane permeability on diffusion and osmosis. The effect of solutions of different tonicity on living red blood cells. Primary active transport: the Na pump. Secondary active transport. Endocytic events mediated by protein-coated wells. Comparison of three types of endocytosis. exocytosis. The key role of in generating the resting membrane potential. G proteins mitochondria. The endoplasmic reticulum. Golgi apparat. Copyright © 2010 Pearson Education, Inc.

Chapter 3 Figure 3.20 Figure Figure Figure Figure

3,21 3,22 3,23 3,24

Figure Figure Figure Figure Figure Figure Figure Figure Figure

3,25 3,26 3,27 3,28 3,29 3,30 3,31 3,32 3,33 3,34

figure figure figure figure

3,35 3,36 3,37 3,38

Figure 3.39

Figure 3.40 Table 3.1 Table 3.2 Table 3.3

Cells: the living units

The sequence of events from the synthesis of proteins in the coarse ER to the final distribution of those proteins. Electron micrograph of a cell with lysosomes (12,000). The endomembrane system. Elements of the cytoskeleton support the cell and contribute to movement. Microtubules and microfilaments function in cell motility by interacting with motor molecules. centrioles. Structure of a tab. ciliary function. microvilli. The nucleus. Chromatin and chromosome structure. The Cell Cycle. Replication of DNA. mitosis. Simplified scheme of the flow of gene information from DNA to mRNA and protein structure during transcription and translation. Overview of the transcription steps. The Genetic Code. The basic steps of translation. Polyribosome arrays allow a single strand of mRNA to be translated into hundreds of the same polypeptide molecules in a short time. The presence of an ER signal sequence in a newly formed protein prompts the signal recognition particle (SRP) to target the mRNA-ribosome complex to the coarse ER. Transmission of information from DNA to RNA to polypeptide. Passive membrane transport processes Active membrane transport processes Parts of the cell: structure and function

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 20. During embryonic development, the embryo loses the membrane between the fingers and toes through a process called apoptosis, or programmed cell death. This process is controlled by the DNA located in the cell nucleus. The organelle within the cell that is responsible for the actual destruction of the cell is the lysosome. (p. 108) 21. Each daughter cell produced after mitosis is genetically identical to the parent cell. Because each cell contains a portion of the original cell, a portion of the first original cell is always found in each of the child cells. In terms of immortality, a cancer cell is truly immortal because it is not constrained by normal cellular limitations and does not actually "age." (p. 97) 22. Ribosomes attached to the ER produce proteins that are exported from the cell, while ribosomes in the cytosol produce proteins that are used inside the cell. (p. 84) Copyright © 2010 Pearson Education, Inc.

39

40

Text and Media Human Anatomy and Physiology - Teacher's Guide 23. The extensions of the cells lining the trachea are cilia. Cilia are extensions of the plasma membrane formed by centriole microtubules. The cilia are used to move airborne mucus and debris up and out of the airways. (pp. 90-91) 24. The three phases of interphase are: G1, during which the cell is metabolically active and growing; S phase when DNA is being replicated; and G2, when the final preparation for cell division takes place. (pp. 95-96) 25. The sodium-potassium pump serves to maintain a polarized state of the membrane by maintaining the diffusion gradient of sodium and potassium ions. The pump couples the transport of sodium and potassium ions so that for each "revolution" of the pump, three sodium ions are expelled from the cell and two potassium ions are returned to the cell. (p. 78) 26. Primary active transport involves a change in conformation of the carrier protein that transports the bound solute directly across the membrane. Secondary active transport, on the other hand, is indirect transport in which the solute is "towed" with another ion that is actively being pumped against its concentration gradient. This pumped ion is generally transported by a primary active transport system. (p. 73) 27. The binuclear state sometimes observed in liver cells occurs when cytokinesis does not occur during cell division. (p. 97)

Critical Thinking Questions and Clinical Application 1. In each case, the living cells were immersed in a hypotonic solution, causing water to permeate the cells. In the case of celery, where the cells are also bounded by cellulose cell walls, water intrusion renders the cell "rigid" due to hydrostatic pressure. In the case of skin cells, as water is absorbed, the cells swell, causing the skin to pucker to accommodate increased cell volume. (pp. 70-72) 2. By interfering with the normal digestion and absorption of food, infectious agents make the gut cell membrane impermeable to dissolved (food) molecules in the gut and dissolved molecules inside. the cells. As a result of this situation, the difference between the osmolarity of the gut content (compartment 1) and the osmolarity of the gut content (compartment 2) not only prevents the gut cell from reabsorbing water, but also causes the water to move quickly from compartment 1 to compartment 2, leading to leads to diarrhea. (p. 71) 3. a. By damaging the mitotic spindle, vincristine inhibits the proper formation of the microtubules, which are used to push the centrioles toward opposite poles of the cell. If this is not the case, the cell cannot complete its mitotic division process and will kill it. (p. 98) b. By binding to DNA and blocking mRNA synthesis, Adriamycin effectively inhibits protein synthesis. Stopping this process prevents the cell from replacing the enzymes and other proteins necessary for the cell's survival. (p. 96) 4. "G1 to S" is actually the time between cell divisions and was formerly called the "rest period" to distinguish it from cell division. In fact, interval 1 is the time when the cell is not dividing but is very metabolically active. It remains in this phase until ready to divide, at which point it transitions to S, or the synthetic phase. In the synthetic phase, DNA is replicated in preparation for cell division. The duration of G1 varies widely from cell to cell, ranging from several minutes to hours in the cell's life in cells that are no longer dividing. Therefore, cells prevented from going from G1 to S would not divide. (pp. 95 and 96) “G2 to M” represents the time interval between interval 2 (G2), which is the time required for the synthesis of the enzymes required for division, and the visible mitosis (M1). here the cells

Copyright © 2010 Pearson Education, Inc.

Chapter 3

5.

6.

7.

8.

Cells: the living units

it would be ready to divide and would have increased DNA, but would not proceed to actual mitosis. Under the light microscope, the chromosomes would not be identified, although there would be amplification of the DNA. The cells would be in prophase. (pp. 95-96) Peroxisomes are the cell organelles that break down toxins. This organelle contains oxidases and catalases. Oxidases use molecular oxygen to detoxify many substances such as alcohol and formaldehyde. (p. 87) Both cilia and flagella are involved in the movement. The cilia propel other substances across the cell surface while the flagella propel the cell itself. A lack of dynein would render both structures dysfunctional. Thus, the normal airway "swing" provided by the cilia lining the lumen of this system would be lost, leading to increased respiratory problems. Loss of a functional flagellum would immobilize sperm and lead to sterility in males. (p. 93) One of the functions of the soft ER is detoxification from drugs such as alcohol. The specific concentration of the enzyme in the smooth ER depends on the need: the cell produces more when the cell's need is greater. The heavy alcohol consumption typical of alcoholics stimulates the production of the smooth ER, which contains enzymes involved in the elimination of alcohol, making cells more efficient at this task. All other things being equal, people who consume little or no alcohol have a much less smooth RE because their detoxification function is much less engaged. (p. 84-85) Salt water is a hypertonic liquid. The kidneys cannot make the urine salty enough to get rid of the excess salt you eat in the salty water. Instead, the kidneys produce more urine, removing needed water from the body, leaving you dehydrated. (p. 70)

Suggested Reading Anderson, Richard G.W. "The Caveolae Membrane System." Annual Review of Biochemistry 67 (1998): 199-225. Bartek, Jiri and Lukas, Jiri. "Extermination Order". Science 294 (5540) (October 2001): 66-67. Vogel, Adrian. "It speaks of methylation between histones and DNA." Science 294 (5549) (December 2001): 2113–2115. Chen, Yu A. and Scheller, Richard H. "Trap-mediated membrane fusion". Nature Reviews: Molecular Cell Biology 2 (February 2001): 98-106. Dahlberg, Albert E. "The Ribosome in Action." Science 292 (5518) (May 2001): 868-869. Dickinson, Boonri. "The Instant Lube for Decoding the Genome". Discover 29 (10) (2008 Oct): 48. Finkel, Elizabeth. "Mitochondria: Is it Essential for Apoptosis?" Science 292 (5516) (April 2001): 624–626. Geiger, B. et al. "Transmembrane Extracellular Matrix - Cytoskeletal Crosstalk". Nature Reviews: Molecular Cell Biology 2 (11) (November 2001): 793-805. Gilooly, David J. and Stenmark, Harald A. "Lipid Oils the Endocytosis Machine." Science 291 (5506) (February 2001): 993-994. Gray, John A. and Roth, Bryan L. "A Last GA SP for GPCR?" Science 297 (5581) (July 2002): 529-532. Hentze, Matthias W. "Believe it or not – Translation at its core." Science 293 (5532) (Aug 2001): 1058–1059. Hughes, Julian R. et al. "A microtubule interactome: complexes with roles in the cell cycle and mitosis". PLoS Biology 6 (April 2008): 785-795. Hunot, Stephane and Flavell, Richard A. "The Death of a Monopoly?" Science 292 (5518) (May 2001): 865–866.

Copyright © 2010 Pearson Education, Inc.

41

42

Text and media handbook of human anatomy and physiology Jesenberger, Veronika and Jentsch, Stefan. "Fatal Encounter: Ubiquitin Meets Apoptosis". Nature Reviews: Molecular Cell Biology 2 (3) (February 2002): 112-120. Keene, Jack D. "RNA Regulons: Coordination of Post-Translational Events." Nature Review: Genetics 8 (July 2007): 533-543. Keys, Andrew R. and Green, Michael R. "The Strange Coupling." Nature 413 (6856) (October 2001): 583-585. King, Ian F. and Kingston, Robert E. "Transcription Specification." Nature 414 (6866) (December 2001): 858–860. Kirchhausen, Thomas. "Three ways to make a gallbladder". Nature Reviews: Molecular Cell Biology 1 (3) (December 2000): 187-198. Lemonick, Michael D. "When Cells Stop Working." Time 168(20) (Nov 2006): 58–59. Marble Stone, Ronen. "Protein molecules that manipulate histone tails for chromatin regulation". Nature: Molecular Cell Biology 2 (6) (June 2001): 422-432. Martinou, Jean-Claude and Green, Douglas R. "Breaking the Mitochondrial Barrier." Nature Reviews: Molecular Cell Biology 2(1) (January 2001): 63–71. MARX, John. "Caveolae: A once elusive structure is gaining some respect". Science 294 (5548) (November 2001): 1862–1865. Mayer, John R. "The Meteoric Rise of Regulated Intracellular Proteolysis." Nature Reviews: Molecular Cell Biology 1(2) (November 2000): 145-148. Mistelli, Tom. "Protein Dynamics: Implications for Nuclear Architecture and Gene Expression". Science 291 (5505) (February 2001): 843-847. Murray, Andrew W. "Centrioles at the Checkpoint." Science 291 (5508) (February 2001): 1499–1502. Nasmyth, Kim. "Segregation of sister genomes: the molecular biology of chromosome segregation". Science 297 (5581) (July 2002): 559-565. Neuman, Andy. "RNA enzymes for RNA splicing". Nature 413 (6857) (October 2001): 695-696. Nigg, Erich A. "Mitotic Kinases as Regulators of Cell Division and Their Checkpoints." Nature Reviews: Molecular Cell Biology 2 (1) (January 2001): 21-32. Pennissi, Elizabeth. "Approaching the centromere". Science 294 (5540) (2001 Oct): 30-31. Pennissi, Elizabeth. "The inner workings of the ribosome become sharper." Science 291 (5513) (March 2001): 2526-2527. Razani, Babak, and Lisaanti, Michael P. "Caveolins and Caveolae: Molecular and Functional Relationships." Experimental Cell Research 271 (2001): 36-44. Regis, ed. "The Forgotten Codebreaker." Scientific American 297 (November 2007). Sheetz, Michael P. "Cellular Control by Membrane-Cytoskeletal Adhesion." Nature Reviews: Molecular Cell Biology 2 (5) (May 2001): 392-396. Shin, Jeoung-Sook and Abraham, Soman N. "Caveolae: not just craters in the cell landscape." Science 293 (5534) (Aug 2001): 1447–1448. Simons, Kai and Toomre, Derek. "Lipid Jangsas and Signal Transduction". Nature Reviews: Molecular Cell Biology 1 (1) (October 2000): 31-39. Slepnev, Vladimir I. and De Camilli, Pietro. "Accessory factors in clathrin-dependent endocytosis of synaptic vesicles". Nature Reviews: Molecular Cell Biology 1 (3) (December 2000): 187-198. Sprong, H. et al. "How proteins move lipids and lipids move proteins". Nature Reviews: Molecular Cell Biology 2 (July 2001): 504-513. VanMeer, Gerrit. "The Different Shades of Lipid Rafts". Science 296 (5569) (2002 May): 855-857.

Copyright © 2010 Pearson Education, Inc.

Stuff: The living stuff

Aims Preparation of human tissue for microscopy 1. List the steps to prepare animal tissue for microscopic observation.

4

8. Describe the types of connective tissue found in the body and give their characteristic functions. Nervous tissue 9. Give the general characteristics of nervous tissue.

Epithelial tissue 2. List several structural and functional features of epithelial tissue. 3. Name, classify and describe the different types of epithelium and indicate their main function(s) and location(s). 4. Define gland. 5. Distinguish between exocrine and endocrine glands and between multicellular and unicellular. 6. Describe how multicellular exocrine glands are structurally and functionally classified. Connective tissue 7. List the common features of connective tissue and list and describe its structural elements.

Muscle Tissue 10. Compare and contrast the body structures and locations of the three types of muscle tissue. Covering and lining membranes 11. Describe the structure and function of skin, mucous and serous membranes. Tissue Repair 12. Describe the tissue repair process involved in the normal healing of a superficial wound. Aspects of tissue development 13. Indicate the embryonic origin of each tissue class. 14. Briefly describe the age-related tissue changes.

Suggested Instructional Process I. Preparing Human Tissue for Microscopy (pp. 114-115) A. Tissue samples should be fixed (preserved) and sectioned (sectioned) so that they are translucent. B. Tissue sections should be stained with dyes that bind to different parts of the cell in slightly different ways so that the anatomical structures can be distinguished from one another.

II. Epithelial tissue (pp. 115-124; Figs. 4.1-4.6) A. Properties of the epithelium (p. 115) 1. An epithelium is a layer of cells covering the body surface or lining a cavity. Copyright © 2010 Pearson Education, Inc.

43

44

Text and Media Teacher's Manual of Human Anatomy and Physiology 2. Epithelium occurs in the body as lining epithelium and glandular epithelium. B. Special features of the epithelium (pp. 115 and 116) 1. Consisting of densely packed cells with little extracellular material between them. 2. Adjacent epithelial cells are connected by specialized contacts such as desmosomes and tight junctions. 3. Presents polarity by having an apical (free) surface and a basal (solid) surface. 4. Supported by underlying connective tissue. 5. Innervated but avascular. 6. It has high regenerative ability. C. Classification of epithelia (pp. 116 and 121; Figs. 4.1 to 4.3) 1. Each epithelial tissue is given two names. a. The first name indicates the number of layers present, simple (one) or layered (more than one). B. The second name describes the shape of the cells. 2. Simple epithelia are mainly concerned with absorption, secretion and filtration. a. Simple squamous epithelium is a single layer of cells shaped like fish scales. B. Simple cuboidal epithelium is a single layer of cuboidal cells that form the smaller ducts of the glands and many renal tubules. C. Simple columnar epithelium is a single layer of columnar cells lining the digestive tract. i.e. Pseudostratified columnar epithelium contains cells of different heights, giving the false impression of many layers. 3. The main function of the stratified epithelium is protection. a. Stratified squamous epithelium consists of several layers, with the free surface cells being squamous and the underlying cells being cuboidal or columnar. B. Stratified cuboidal epithelium is rare and is found chiefly in the ducts of some of the larger glands. C. Stratified columnar epithelium is found in a limited distribution with small amounts in the pharynx, male urethra, and lining some glandular ducts. i.e. The transitional epithelium forms the lining of the hollow organs of the urinary system, which stretch as they fill. D. Glandular Epithelium (pp. 121-124; Figs. 4.4-4.6) 1. Endocrine glands are blood glands that secrete hormones directly into the blood or lymph by exocytosis. 2. Exocrine glands have ducts and secrete their product onto a surface or into body cavities. a. Exocrine glands can be unicellular or multicellular. B. Exocrine secretions in humans can be merocrine, which are products released by exocytosis, or holocrine, which are synthesized products released when the cell ruptures.

3. Connective tissue (p. 124-134; Fig. 4.1, 4.7-4.8; Table 4.1) A. Functions of connective tissue (p. 124; Fig. 4.1) 1. The main functions of connective tissue are attachment and support, protection, insulation and transportation.

Copyright © 2010 Pearson Education, Inc.

Chapter 4

Stuff: The living stuff

B. Connective Tissue Similarities (p. 124) 1. All connective tissue arises from an embryonic tissue called mesenchyme. 2. Connective tissue varies from avascular to highly vascularized. 3. Connective tissue consists primarily of non-living extracellular matrix that separates cells from tissue. C. Structural Elements of Connective Tissue (pp. 124-126; Figs. 4.7-4.8a) 1. Ground substance is the unstructured material that fills the space between cells and contains fibers. 2. Connective tissue fibers provide support. a. Collagen fibers are extremely strong and give the connective tissue high tensile strength. B. Elastic fibers contain elastin, which allows them to stretch and contract. C. Reticular fibers are thin collagen fibers that form networks. 3. Each major class of connective tissue has a basic cell type that exists in immature and mature forms. D. Connective Tissue Types (pp. 126-134; Fig. 4.8; Table 4.1) 1. Mesenchyme forms from the mesodermal layer during the first weeks of embryonic development and eventually differentiates into all other connective tissues. 2. Loose connective tissue is one of two subclasses of connective tissue proper. a. Areolar connective tissue serves to connect body parts together, to be able to move freely over one another, encloses small blood vessels and nerves, encloses glands and forms subcutaneous tissue. B. Adipose tissue is a richly vascularized tissue that serves to store, protect, and isolate nutrients. C. Reticular connective tissue forms the internal framework of the lymph nodes, spleen, and bone marrow. 3. Dense connective tissue is one of two subclasses of connective tissue proper. a. Regular dense connective tissue contains densely packed bundles of collagen fibers that run in the same direction, forming tendons and ligaments. B. Dense irregular connective tissue containing thick bundles of irregularly arranged collagen fibers is found in the dermis. 4. Cartilage has no nerve fibers and is avascular. a. Hyaline cartilage is the most common cartilage and provides strong support with some malleability. B. Elastic cartilage is found where exceptional strength and elasticity are needed, such as in the B. the outer ear. C. Fibrocartilage is found where strong support and the ability to withstand intense pressure is required, such as in the B. in intervertebral discs. 5. Bones (bone tissue) have an exceptional ability to support and protect body structures due to their hardness, which is determined by the extra collagen fibers and calcium salts in the extracellular matrix. 6. Blood is called connective tissue because it developed from mesenchyme and consists of blood cells and plasma proteins surrounded by blood plasma.

4. Nervous Tissue (pp. 134-136; Figs. 4.1, 4.9) A. Nervous tissue is the main component of the nervous system and regulates and controls bodily functions (p. 134; Fig. 4.1).

Copyright © 2010 Pearson Education, Inc.

45

46

Text and Media Teacher's Manual of Human Anatomy and Physiology B. Nervous tissue consists of two types of cells. (p. 136; Fig. 4.9) 1. Neurons are specialized cells that generate and transmit electrical impulses. 2. Support cells are non-conductive cells that support, insulate, and protect neurons.

V. Muscle Tissues (pp. 136-137; Figs. 4.1, 4.10) A. Muscle tissues are highly cellular, well-vascularized tissues responsible for movement (p. 136; Fig. 4.1). B. There are three types of muscle tissue (p. 136; Fig. 4.10): 1. Skeletal muscle attaches to the skeleton and produces voluntary body movements. 2. The heart muscle is responsible for the involuntary movement of the heart. 3. Smooth muscle is found in the walls of hollow organs.

SEEN. Covering and Lining Membranes (p. 138; Fig. 4.11) A. The dermal membrane or skin is an organ system composed of a keratinized squamous epithelium tightly attached to a thick layer of dense, irregular connective tissue (p. 138). B. Mucous membranes line body cavities which open outward and contain simple columnar or stratified squamous epithelium (p. 138). C. Serous membranes consist of simple squamous epithelium resting on a thin layer of loose connective tissue (areoles) (p. 138).

VIII. Tissue Repair (pp. 138-141; Fig. 4.12) A. Tissue repair occurs in two ways: regeneration and fibrosis (p. 138). B. The tissue repair process involves three steps (pp. 139-140; Fig. 4.12). 1. Inflammation prepares the area for the repair process. 2. The organization restores the blood supply. 3. Permanent restoration of regeneration and fibrosis effect. C. The generative capacity of tissues varies greatly between tissue types (pp. 140-141).

VIII. Aspects of Tissue Development (pp. 141, 144; Fig. 4.13) A. Embryonic and Fetal Tissue Development (pp. 141, 144; Fig. 4.13) 1. The formation of the primary germ layer is one of the earliest events in embryonic development. a. The ectoderm is the most superficial layer. B. The mesoderm is the middle layer. C. The endoderm is the deepest layer. 2. The primary germ layers specialize to form the four primary tissues. B. With age, the epithelia thin, the number of collagen fibers in the body decreases, and bone, muscle, and nerve tissue atrophy (p. 144).

Cross-references For more information on the topics discussed in Chapter 4, see the chapters listed below. 1. Chapter 1: The Hierarchy of Structural Organization; ventral body cavity divisions

Copyright © 2010 Pearson Education, Inc.

Chapter 4

Stuff: The living stuff

2. Chapter 5: The function of keratin in the keratinized stratified squamous epithelium; dermal membrane (skin); function of the basement membrane in the skin; role of connective tissue in the integument; exocrine glands in the skin 3. Chapter 6: Bone tissue and bone structure and growth; formation of bone tissue; Chondrocytes and cartilage in bone formation 4. Chapter 8: Connective tissue in ligaments and tendons; Cartilage in Joint Formation 5. Chapter 9: Skeletal and Smooth Muscle; connective tissue covering the muscles 6. Chapter 11: Nervous Tissue 7. Chapter 13: Function of Nervous Tissue 8. Chapter 16: Endocrine (Endocrine) Glands 9. Chapter 17: Blood 10. Chapter 18: Cardiac Muscle; serous coverings of the heart, epithelium of the heart and connective tissue in the heart valves; Function of Nervous Tissue 11. Chapter 19: Epithelial and Connective Tissue Components of Blood Vessels 12. Chapter 20: Interstitial Fluid (Generation and Elimination); reticular connective tissue supporting lymphoid tissue 13. Chapter 21: Inflammatory and immune responses 14. Chapter 22: Cartilaginous support of respiratory structures; pseudostratified epithelium lining the trachea 15. Chapter 23: Epithelial and secretory cells of the gastrointestinal tract 16. Chapter 25: Properties of filtering, secreting and resorbing epithelial cells

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 6A: Tissue Classification 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 6A: Tissue Classification

Teaching Tips 1. The relationship between structure and function is important and can be easily illustrated using examples of epithelial tissue. Emphasize that the multilayered structure of stratified squamous epithelium is much better suited to surfaces subject to wear, while simple squamous epithelium is better suited to filtration. 2. Stratified squamous epithelium is usually the first of the stratified epithelial tissues to appear. Emphasize that only the surface cells are flattened. The student's first idea is often that tissue is made up of multiple layers of thin, flat cells. 3. Emphasize the uniqueness of the matrix when explaining the classification of connective tissue. This is helpful because this group of tissues will appear very different to the students. Students can often lose sight of how and why such a diverse group is categorized together. Also relate the type of matrix to the specific function of the tissue. 4. To illustrate the structure-function relationship presented in Chapter 3, compare the amount of extracellular matrix in connective tissue to

Copyright © 2010 Pearson Education, Inc.

47

48

Text and media guide to human anatomy and physiology

5.

6. 7. 8.

9. 10. 11.

12

than in epithelial tissue. Note that connective tissue is made up of at least 50% extracellular matrix, which is what gives these tissues their strength and structure. Note that epithelial tissue is totally unable to perform the structural functions of connective tissue due to its relative lack of matrix. Students are sometimes confused as to why collagen and elastic fibers are labeled as white and yellow fibers respectively, when viewed microscopically they appear pink and black respectively. This is because the prepared samples are colored and not natural. Point out that hyaline cartilage contains large numbers of collagen fibers, although these are not visible on laboratory slides. Emphasize that cartilage is avascular and this results in a slow rate of repair or healing. When presenting information about bones (bone tissue), emphasize that it is a living tissue that has a direct blood supply. Often students have the idea that bone is an inanimate material (based on laboratory observations). Mention that the "fibers" in blood are unique in that they are made of a soluble protein that only becomes insoluble during the clotting process. Epithelial membranes consist of epithelial and connective tissue. The best example of this is the skin (skin membrane). To give students some insight into tissue specialization, remember that there are specific structural and functional adaptations that make each type of muscle tissue uniquely suited for use in the body. Point out some fundamental aspects of each tissue that would make it unsuitable for use with other muscle types. Emphasize that regeneration is not the same as repair.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Ask students to list all the things the body could not do if connective tissue was missing. 3. Using moderate pressure, scrape a fingernail across the front surface of the forearm to demonstrate the onset of the inflammatory response (redness, swelling). 4. Cut through a flatworm in the lab and watch the missing body region regenerate over the next few weeks. 5. Use three-dimensional models such as a cube (for cuboids), a fried egg (for squamous cells), or a cup (for columns) to illustrate the different types of epithelial tissue. 6. Obtain or prepare 22 slides of all tissues used during the histology lesson presentation. 7. Illustrate how fabrics are cut to show how thin sections are made. Remind students that slides contain only a small, thin piece of tissue and that there can be more than one type of tissue on a slide. 8. Use models of epithelial tissue, connective tissue, muscle cells and a neuron to illustrate how cells from different tissue types are similar and different. 9. Cover your wrist with a collapsed balloon to demonstrate the relationship between the parietal and visceral layers of a serous membrane. 10. Use a human torso model to show the location of the mucous membranes and serous membranes. 11. Use skeletal, cardiac, and smooth muscle models to compare and contrast these tissue types.

Copyright © 2010 Pearson Education, Inc.

Chapter 4

Stuff: The living stuff

Critical Thinking/Points for Discussion 1. How are tissues prepared and sectioned to create the various tissue sections in this book? 2. How are tissues used in the body to form specific body compartments and why is this necessary? 3. What is the medical significance of the penetration of a microorganism into the tissues of the body that can break down collagen? Give an example and describe the disease that causes it. 4. If all cells in the body arise from the same embryonic cell (zygote), how can each cell assume specific functions? Could any of these differentiated cells revert to a different cell type? 5. Bone, hair and even teeth can be found in some cysts and tumors. How can this happen? 6. Since cartilage is avascular, how is it supplied with the necessities of life? 7. Besides reducing bleeding and preventing microbial invasion, why are wounds stitched? 8. There appears to be an inverse relationship between regenerative potential and degree of tissue specialization. Why can that be?

Research Topics of the Library 1. Basement membranes form the interface between epithelium and connective tissue. What is the chemical composition of this layer and why is this zone of great interest to cell biologists? 2. What is the current status of cloning? Is it viable for human cells? 3. What is a suction lipectomy? Who can perform this procedure? 4. Why are some cells able to regenerate and others not? What are the pros and cons in both cases? 5. Compare the advantages and disadvantages of using embryonic stem cells versus stem cells derived from tissues such as bone marrow or skin. 6. Describe the different types of tissues that can be removed from an area of ​​a patient to augment or reshape other parts of the body during plastic surgery and describe how these tissues are used.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all chapter-specific online media resources for Chapter 4 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 4.1 Preparation of human tissue for microscopy (pp. 114 and 115) Section 4.2 Epithelial tissue (pp. 115 and 124)

Copyright © 2010 Pearson Education, Inc.

49

50

Text and media Teacher's guide to human anatomy and physiology Art lettering: Types of multicellular exocrine glands (Fig. 4.5, p. 123) Memory game: Organization of body tissue Section 4.3 Connective tissue (pp. 124-136) Art lettering: Areolar connective tissue Tissue (Fig. 4.7, p. 125) Memory game: connective tissue Appropriate section 4.4 Nervous tissue (pp. 134-136) Game of ten Interactive Systems Physiology®: Anatomy of the nervous system Review Section 4.5 Muscle tissue (pp. 136-137 ) Interactive Physiology® 10-System Suite: Overview of the anatomy of skeletal muscle tissue Section 4.6 Coating and lining membranes (p. 138) Section 4.7 Tissue repair (pp. 138-141) Case study: cirrhosis of the liver Section 4.8 Aspects of tissue development (pp. 141-144) Case study: birth defects Chapter summary Crossword 4.1 Crossword 4.2 Crossword 4.3 Web links Chapter quiz o Labeling quiz Art combination test Multiple choice test Dir pass-or-false test practical chapter test learning tools histology atlas myeBook flashcards glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Slides 1. Basic Set of Epithelial Types (CBS) 2. Basic Set of Medical Histology (CBS). Set of 50 slides covering a wide range of histology. 3. Connective Tissue Basic Set (CBS) 4. Connective Tissue Type Set (CBS)

Copyright © 2010 Pearson Education, Inc.

Chapter 4

Stuff: The living stuff

5. Human Connective Tissue Structure (CBS) 6. Human Muscle Tissue Structure (CBS)

Video 1. Cooperation of organ systems (WNS; 14 min). This program introduces students to the functions of the organ systems of the human body. It's an excellent overview of all systems, with a special animated sequence showing how each organ system in the human body developed from a single cell from a fertilized egg.

Software 1. Transverse Anatomy Tutor on CD-ROM (FHS; Windows). The interactive tutorial correlates normal transverse anatomy with X-ray images of CT and MR images. 2. Interactive CD-ROM with histological resources (WNS; Win/Mac). The slides cover the cytology of most major systems. Contains verbose text describing structures, shapes, and functions. Printable quizzes included on CD. 3. Practice Anatomy Lab™ 2.0: Histology (see full list on page 9 of this manual). 4. Atlas of Pathology (FHS; Win/Mac). Extensive database of pathological images with associated medical information. 5. WARD Histology Collection CD-ROM (WNS; Win/Mac). A collection of slides to help students explore the microanatomy of organ systems. The CD can be used for presentation or one-to-one discussion. Contains 384 images and a full text file.

Material to improve the lesson Thumbnails of all illustrations in Chapter 4 can be found in Appendix B.

Figure 4.1 Figure 4.2 Figure 4.3 Figure 4.4 Figure 4.5 Figure 4.6 Figure 4.7 Figure 4.8 Figure 4.9 Figure 4.10 Figure 4.11 Figure 4.12 Figure 4.13 Table 4.1 A closer look

Summary of four tissue types: epithelial, connective, muscular and neural. Classification of epithelia. epithelial tissue. Goblet cell (unicellular exocrine gland). Types of multicellular exocrine glands. Main types of secretion in human exocrine glands. Areolar connective tissue: a prototype (model) of connective tissue. Connective tissue. nerve tissue. muscle tissue. membrane classes. Tissue repair of an unextended skin wound: regeneration and fibrosis. Embryonic cotyledons and the types of primary tissues they produce. Comparison of connective tissue cancer classes: the intimate enemy

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Copyright © 2010 Pearson Education, Inc.

51

52

Text and media guide to human anatomy and physiology

Short Answer Essay Questions 7. Tissues are tightly-knit groups of cells that are structurally similar and share a common function. (p. 114) 8th shield: squamous epithelium stratified; Absorption - single columnar; filtration - simple squamous epithelium; Secretion - simple cuboid. (p. 117) 9. Lining and lining epithelia are classified based on the shape of the cells and the number of cell layers present. The three most common shapes are scaly, cuboid, and columnar. The classes in terms of the number of cells are: simple (single-layer) or stratified (multi-layer). In some cases, such as the endothelium, it is important to indicate its specific location in the body. (p. 116) 10. Merocrine glands (sweat glands) excrete their products by exocytosis; holocrine glands (sebaceous glands) release their products by lysing the entire cell; Apocrine cells (not thought to be present in humans) release their products by removing portions of the cell's contents. (p. 122) 11. Appendix: areolar; support - cartilage; protection - bones; Isolation - greasy; and transport - blood. (pp. 124, 126-133) 12. Fibroblast; chondroblast; Osteoblast (p. 125) 13. Ground substance: interstitial fluid, proteoglycans and glycosaminoglycans; collagenous, elastic, reticular fibers. (pp. 124 and 125) 14. The matrix achieves its position due to the secretion of its components by undifferentiated (blastic) cells located throughout the matrix. (p. 125) 15. a. Areolar (p. 126) b. elastic cartilage (p. 133) c. elastic connective tissue (p. 131)

16. 17.

18. 19.

20. 21.

i.e. mesenchyme (p. 126) e. fibrous cartilage (p. 133) f. hyaline cartilage (p. 131) g. areolar connective tissue (p. 126) The macrophage system is involved in the entire defense of the body. Its cells are phagocytic and participate in the immune response. (p. 126) Neurons are highly specialized cells that generate and transmit nerve impulses, while supporting cells (glial cells) are nonconductive cells that support, insulate, and protect neurons. (p. 134) See Figure 4.10, which illustrates the location, function, and description of the three muscle types. (p. 137) Tissue repair begins during the organized inflammatory response, during which the blood clot is replaced by granulation tissue. If the wound is small and the damaged tissue is actively mitotic, the tissue regenerates and covers the fibrous tissue that is forced to fill the space. When a wound is extensive or the damaged tissue is amitotic, it is repaired only with fibrous connective tissue (scar tissue). (pp. 138 to 140) Ectoderm: epithelial and nervous; mesoderm: connective tissue, muscle and epithelium; endoderm - epithelium. (p. 141) Adipose and bone tissues are similar in that both tissues are connective tissues with ample blood supply and are used for nutrient storage. They differ in their relative amounts of extracellular matrix and location of nutrient storage. Bones have an extensive extracellular matrix and this is where nutrients are stored. Adipose tissue has little extracellular matrix and stores nutrients inside the cells. (pages 127, 133)

Copyright © 2010 Pearson Education, Inc.

Chapter 4

Stuff: The living stuff

Critical Thinking Questions and Clinical Application 1. No. Cartilage heals slowly because it lacks the blood supply necessary for the healing process. (p. 131) 2. The skin is subjected to almost constant friction, which wears down the superficial cells and is responsible for preventing the penetration of harmful substances and the loss of water from the body. A stratified squamous epithelium, with its many layers, is much better able to resist abrasion than a simple epithelium (cells with a single layer); in addition, stratified epithelia regenerate more efficiently than simple epithelia. Finally, keratin is a resilient water-repellent protein that plays a role in preventing dehydration and acts as a physical barrier against harmful agents. Because the mucosa is a moist membrane, it would be ineffective in preventing water loss from the deeper tissues of the body. (pp. 119-138) 3. If the ligaments had more elastic fibers, they would be more elastic; So the joints would be more flexible. However, the function of the ligaments is to hold the bones securely together for proper and controlled movement of the joints. More elastic ligaments would result in flexible joints where the bones involved in the joint would be prone to misalignment and displacement. (p. 129) 4. Epithelium, because epithelia remain mitotic throughout life. This is not the case with nerve and muscle tissue and some forms of connective tissue. (pp. 116, 138) 5. While "white" fat stores nutrients, "brown" fat uses its stores of nutrients to generate heat and actually weighs less than white fat. Brown fat only occurs in limited areas of the body, while white fat is found subcutaneously all over the body. Remember that brown fat is only found in babies and cannot be converted to white fat. (p. 127) 6. Filet mignon is a skeletal muscle. Cow intestine is digestive smooth muscle. (p. 136)

Suggested Reading Cormack, DH Essential Histology. 2nd ed. New York: J.B. Lippincott Company, 2000. Jones, Peter A. "Cancer: Death and Methylation." Nature 409 (6817) (January 2001): 142–144. McCormick, Frank. "New Age Drug Meets Resistance." Nature 412 (6844) (July 2001): 281-282. Pet, Julian. "Cancer Epidemiology in the Past Century and Next Decade". Nature 411 (6835) (2001 May): 390-395. street, Dennis. A color atlas of histology. San Francisco: Benjamin Cummings, 1995. Travis, J. "Aging cells may promote nearby tumors." Science News 160(14) (October 2001): 214. Van De Water, Livingston. "Tissue Engineering: Regulation of the Wound Healing Response". Science and Medicine 7(2) (March–April 2000): 6–7. Vogelstein, Bert and Kinzler, Kenneth W. "The Achilles' Heel of Cancer?" Nature 412 (6850) (Aug 2001): 865–866.

Copyright © 2010 Pearson Education, Inc.

53

5

The integumentary system

Objectives The skin 1. Name the types of tissues that make up the epidermis and dermis. List the main layers of each and describe the functions of each layer. 2. Describe the factors that commonly contribute to skin color. Briefly describe how changes in skin color can be used as clinical signs of certain disease states. Skin appendages 3. Compare the structure and location of the sweat and sebaceous glands. Also compare the composition and functions of their secretions. 4. Compare and distinguish eccrine and apocrine glands. 5. List the parts of a hair follicle and explain the function of each part. Also describe the functional relationship of the arrector pili muscle to the hair follicles.

6. Name the regions of a hair and explain the basics of hair color. Describe the distribution, growth, replacement and change in nature of hair throughout life. 7. Describe the structure of the nails. Functions of the skin system 8. Describe how the skin performs at least five different functions. Skin Homeostatic Imbalance 9. Explain why severe burns are life threatening. Describe how you determine the extent of a burn and distinguish between first, second, and third degree burns. 10. Summarize the characteristics of the three main types of skin cancer. Aspects of the development of the skin system 11. Describe and explain the causes of skin changes from birth to old age.

Suggested Lesson Plan I. The Skin (pp. 149-155; Figs. 5.1-5.4) A. The hypodermis, also known as the superficial fascia, is a subcutaneous tissue under the skin composed primarily of fatty tissue that holds together the skin of the underlying muscle, allows the skin to slide over the muscle and acts as a shock absorber and insulator (p. 149; Fig. 5.1). B. Epidermis (pp. 150-152; Fig. 5.2) 1. The epidermis is a keratinized stratified squamous epithelium. 2. Epidermal Cells a. Most epidermal cells are keratinocytes, which produce a protective fibrous protein called keratin. B. Melanocytes are epithelial cells that synthesize the pigment melanin.

54 Copyright © 2010 Pearson Education, Inc.

Chapter 5

The integumentary system

C. Epidermal dendritic cells or Langerhans cells are macrophages that help activate the immune system. i.e. Tactile cells are associated with sensory nerve endings. 3. Layers of the Epidermis a. The stratum basalis (stratum basalis) is the deepest epidermal layer and is the site of mitosis. B. The stratum spinosum (stratum spinosum) has several layers of thick cells and contains keratinocytes, melanin granules and the highest concentration of epidermal dendritic cells. C. The stratum granulosum (granular layer) contains keratinocytes, which undergo many physical changes, transforming them into the tough outer cells of the epidermis. i.e. The stratum lucidum (light layer) is found only in thick skin and consists of dead keratinocytes. Y. The stratum corneum is the outermost protective layer of the epidermis, made up of a thick layer of dead keratinocytes. C. Dermis (pp. 152 and 153; Figs. 5.3 and 5.4) 1. The dermis is composed of strong, flexible connective tissue. 2. The dermis consists of two layers: the thin superficial papillary layer is a highly vascular areolar connective tissue containing a woven mat of collagen and elastin fibers; and the reticular layer, which accounts for 80% of the thickness of the dermis, consists of dense and irregular connective tissue. D. Skin color is determined by three pigments: melanin, hemoglobin, and carotene (pp. 154-155).

II. Skin appendages (pp. 155-160; Figs. 5.5-5.7) A. Sweat glands (pp. 155-156; Fig. 5.5) 1. Eccrine sweat glands or merocrine sweat glands produce real sweat. numerous from the sweat glands, and are especially abundant on the palms, soles, and forehead. 2. Apocrine sweat glands are limited to the axillae and anogenital area and produce real sweat with the addition of fatty substances and proteins. 3. Cerumenous glands are modified sweat glands located in the lining of the ear canal that secrete wax or cerumen. 4. Mammary glands are modified sweat glands in the breasts that secrete milk. B. Sebaceous Glands (pp. 156-157; Fig. 5.5) 1. Sebaceous glands are simple alveolar glands found throughout the body except for the palms and soles, which secrete sebum, an oily secretion. 2. Sebaceous glands function as holocrine glands that secrete their product into a hair follicle or pore on the skin's surface. 3. Hormones stimulate the secretion of the sebaceous glands. C. Hair and Hair Follicles (pp. 157-159; Fig. 5.6) 1. Hairs or pili are flexible strands produced by hair follicles composed of dead cornified cells. a. The main regions of a hair are the shaft and the root. B. A hair has three layers of keratinized cells: the inner core is the medulla, the middle layer is the cortex, and the outer layer is the cuticle.

Copyright © 2010 Pearson Education, Inc.

55

56

Text and media manual for instructors in human anatomy and physiology c. Hair pigments (melanin of different colors) are produced by melanocytes at the base of the hair follicle. 2. Structure of a hair follicle a. Hair follicles fold from the epidermis to the dermis and occasionally to the hypodermis. B. The deep end of a hair follicle expands to form a hair bulb surrounded by a knot of sensory nerve endings called the hair follicle receptor or radicular hair plexus. C. The wall of a hair follicle consists of an outer connective tissue root sheath, a thickened basement membrane called the glossy membrane, and an epithelial inner root sheath. i.e. Associated with each hair follicle is a bundle of smooth muscle cells called the arector pili muscle. 3. Hair Types and Growth a. Hair comes in many sizes and shapes, but can be classified as downy or terminal. B. Hair growth and density are influenced by many factors, including diet and hormones. C. The rate of hair growth varies from one body region to another and with gender and age. 4. Hair Loss and Balding a. After the age of 40, hair does not replace as quickly as it is lost, leading to thinning hair and some degree of balding or alopecia in both sexes. B. Male pattern baldness, which is a true or overt type of baldness, is a genetic and sex-linked condition. D. Nails (p. 160; Fig. 5.7) 1. A nail is a scaly modification of the epidermis that forms a transparent protective covering. 2. Nails are made of hard keratin and have a free edge, a free body and a proximal root.

3. Functions of the skin system (pp. 160-162) A. Protection (pp. 160-161) 1. Chemical barriers include skin secretions and melanin. 2. The physical or mechanical barriers are provided by the continuity of the skin and the hardness of the keratinized cells. 3. Biological barriers include epidermal dendritic cells, dermal macrophages, and DNA itself. B. The skin plays an important role in regulating body temperature, using sweat glands in the skin to cool the body and contracting skin capillaries, to prevent heat loss (p. 161). C. Skin sensation is enabled by the placement of cutaneous sensory receptors, which are part of the nervous system, in the layers of the skin (p. 161). D. The skin performs the metabolic function of producing vitamin D when exposed to sunlight (p. 161). E. The skin can act as a blood reservoir, containing up to 5% of the body's blood supply, which can be diverted to other areas of the body when needed (pp. 161-162). F. Limited amounts of nitrogenous waste are excreted through the skin (p. 162). Copyright © 2010 Pearson Education, Inc.

Chapter 5

The integumentary system

4. Skin homeostatic imbalance (pp. 162-165; Fig. 5.8-5.10) A. Skin cancer (pp. 162-163; Fig. 5.8) 1. Basal cell carcinoma is the least malignant skin cancer and is the most common. 2. Squamous cell carcinomas tend to grow rapidly and metastasize if not removed. 3. Melanoma is the most dangerous skin cancer because it metastasizes extensively and is resistant to chemotherapy. B. Burns (pp. 163-165; Figs. 5.9-5.10) 1. A burn is tissue damage caused by intense heat, electricity, radiation or certain chemicals that denature all cell proteins and in the infected areas the cause cell death. 2. The most immediate threat to a burn patient is dehydration and an electrolyte imbalance due to fluid loss. 3. After the first 24 hours, the threat to a burn patient becomes infection at the wound site. 4. Burns are classified according to their severity. a. In first-degree burns, only the epidermis is damaged. B. Second degree burns damage the epidermis and upper dermis. C. Third degree burns involving the full thickness of the skin.

V. Developmental Aspects of the Integumentary System (p. 165) A. The epidermis develops from the embryonic ectoderm, and the dermis and hypodermis develop from the mesoderm (p. 165). B. At the end of the fourth month of development the skin is fairly well developed (p. 165). C. During childhood, the skin thickens and more subcutaneous fat is deposited (p. 165). D. During puberty, skin and hair become oilier as the sebaceous glands are activated (p. 165). E. Skin reaches its ideal appearance in your 20's and 30's; After this time, the skin shows the effects of cumulative environmental exposure (p. 165). Q. With age, the rate of renewal of epidermal cells decreases and the skin thins, making it more susceptible to bruising and other types of injury (p. 165).

Cross-references For more information on the topics covered in Chapter 5, see the chapters listed below. 1. Chapter 3: Desmosomes 2. Chapter 4: Stratified squamous epithelium, keratinized; basement membrane; loose connective tissue (areolar); irregular dense connective tissue; fibers in the connective tissue matrix; simple convoluted tubular glands; simple branched alveolar glands; merocrine glands; holocrine glands 3. Chapter 13: Skin sensation and reflex action 4. Chapter 15: Sebaceous and sweat glands of the auditory canal

Copyright © 2010 Pearson Education, Inc.

57

58

Text and Media Teacher's Guide to Human Anatomy and Physiology 5. Chapter 21: Organ and Tissue Transplantation and Rejection Prevention; Non-specific mechanical and chemical defense mechanisms 6. Chapter 23: Jaundice and bilirubin accumulation 7. Chapter 24: Regulation of body temperature 8. Chapter 28: Action of androgens

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 7: The integumentary system Exercise 8: Classification of covering and lining membranes 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 7: The skin system Exercise 8: Classification of cover and lining membranes

Tips for Lesson 1. The basal and spine layers are often referred to collectively as the growth (germ) layers. Some authors are of the opinion that the germ layer is only the basal layer. Students are easily confused when the terminology is not consistent between the lesson, the text, and the lab test. 2. Emphasize that the hypodermis is not a layer of skin, but the superficial fascia beneath the skin. Point out that deep beneath the skin is fascia, which will be discussed later in Chapter 9. 3. The hypodermis (superficial fascia) is an important storage location for fat that insulates the body. This layer is more pronounced in women than in men, resulting in a softer feel to the touch. This smoother skin is considered a secondary sexual characteristic of women. 4. Analyze the activity of melanocytes, the production of melanin and the level of ultraviolet radiation. Point out the genetic basis of melanocyte activity and the geographic distribution of human ancestors as an explanation for racial differences. Explain the effect of UV exposure levels and tanning on humans. 5. During the lab, students generally attempt to locate and identify the stratum lucidum on all skin sections. Point out that this layer of epidermis is only present in thick skin. 6. Explain that the skin plays a role in regulating body temperature by evaporating sweat and controlling blood flow through the dermal blood vessels. 7. Some sebaceous glands are not connected to hair follicles and open directly on the skin's surface. Examples are the oil glands of the skin, lips and eyelids (tarsal glands). 8. The actual contact with the environment is through a layer of dead (instead of living) cells. This specialization was essential to the evolution of life forms that could survive in a terrestrial environment.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory.

Copyright © 2010 Pearson Education, Inc.

Chapter 5

The integumentary system

2. Show the students a picture of a very wrinkled person. Ask them to list any factors that contributed to the observed skin deterioration. 3. Prepare small glass bowls and have students observe the change in their skin color while pressing their palms firmly against the glass. Ask them to explain the color change and what would happen to the skin if the pressure was longer. 4. Run a small fan. When students enter the classroom, spray water on their arm or hand. Ask them to describe the sensation when water evaporates from the skin and why evaporation of water (or sweat) is important for temperature homeostasis. Repeat the demonstration with alcohol and ask why the cooling effect is greater. 5. Use 3D skin models to illustrate layers and layers. 6. Use a microprojector and microscope slides of the skin to visualize the layers. Use skin incisions from the scalp and palm to contrast differences in layers.

Critical Thinking / Discussion Points 1. What is the role of the skin in regulating body temperature? 2. Why exactly do thick-coated animals like Alaskan huskies withstand extremely cold temperatures? 3. Humans are often referred to as "naked monkeys". Although we have numerous hair follicles all over our bodies, why do you think we don't have body hair? 4. If skin acts as a barrier to most substances, how can it trigger an allergic reaction to things like poison ivy? 5. Many organisms, such as snakes, insects, and grasshoppers, shed their "skin" on a regular basis. How does this compare to the process that occurs in humans? 6. The air is 80˚F and the temperature of the lake is 70˚F. Why do you freeze the first time when you go into the water? Why do you freeze when you get out of the water? 7. Why doesn't armpit hair grow as long as head hair? How long would the hair on the scalp grow if not cut? 8. Discuss the pros and cons of using the drug minoxidil to stimulate hair growth in bald men. 9. Which structures in the dermis are of epidermal origin? 10. When fair-skinned people go outside on a cold and windy day, their skin turns "white" and then "red" after a while. to explain. 11. Nancy has dry skin and prefers to shower at night. Would it be more effective for her to apply a skin care lotion like Keri Lotion in the morning or evening after showering? There? 12. Why is it more difficult to get a tan during the winter months, even though the sun is closer to the earth at this time of year? 13. People who live in Ohio can be in the sun for three hours without getting burned, but if they go to Florida for spring break, they can get burned after just two hours. There? 14. Describe the difference between type A and type B UV rays in terms of skin damage. 15. Why does a tan eventually fade? 16. Why are wounds stitched apart from reducing bleeding?

Copyright © 2010 Pearson Education, Inc.

59

60

Text and media guide to human anatomy and physiology

Library Research Topics 1. Search the literature on the latest techniques and materials, such as B. test tube skin, synthetic skin and xenograft skin used in skin grafts. 2. Long-term effects of sunburn appear to be severe skin wrinkling and skin cancer. What are the latest stats on this issue and what has been done to fix it? 3. What are the latest therapies for balding? 4. Although our skin provides a "barrier" to microbes, make a list of microbes such as bacteria, yeast, fungi, protozoa, and arthropods that can live on or in our skin. 5. Accutane (isotretinoin) is a prescription drug that was approved in the early 1980's for the treatment of severe cystic acne. Is this medicine safe to use during pregnancy? Student Activity 6: Find signs and symptoms of basal cell carcinoma, squamous cell carcinoma, and malignant melanoma to discuss in class.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all chapter-specific online media resources for Chapter 5 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Learning Outcomes Section 5.1 The Skin (pp. 149-155) MP3 Tutor Session: Layers and Associated Structures of the Integument Labeled Art: Structure of the Skin (Fig. 5.1, p. 149) Memory Game: Components of the Skin Membrane Memory Game: Constituents of the Skin System Section 5.2 Skin Appendages (pp. 155–160) Artist's label: Structure of a hair follicle (Fig. 5.6, p. 158) Artist's label: Structure of a fingernail (Fig. 5.7, p. 160) Section 5.3 Functions of the integumentary system (pp. 160–162) Chapter 5.4 Homeostatic imbalance of the skin (p. 162-165) Case study: burns Case study: athlete's foot Case study: skin cancer Chapter 5.5 Aspects of development of the integumentary system ( p. 162-165) 165) Chapter summary Crossword puzzle 5.1 Crossword puzzle 5.2 Crossword puzzle 5.3 Web links

Copyright © 2010 Pearson Education, Inc.

Chapter 5

The integumentary system

Chapter test Art identification test Combined test Multiple choice test (Level I) Multiple choice test (Level II) True/False quiz Chapter Practice test Learning tools Histology atlas myeBook Flashcards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Slides 1. Human body systems: the skin and its functions (CBS) 2. Skin types (CBS) 3. Types of integuments (CBS)

Video 1. The dangers of melanoma (FHS; 29 min, 2003). This Dartmouth-Hitchcock Medical Center production promotes sun exposure precautions and self-examination as a means of reducing the risk of melanoma. Commentary from an epidemiologist, dermatologist, oncologist and patient who has lived with melanoma. 2. The Integumentary System (IM; 43 min., 2003). This program examines the composition of the skin system, explores the sensory organs and looks at the functions and processes of each component. 3. Skin (FHS; 20 min, 1995). Contains live-action video using the latest imaging technology. Provides insights into the inner workings of the human body. It provides an interesting and informative presentation for the whole class. 4. Plastic and Reconstructive Surgery (ESF; 19 min.). This video explains some of the most common cosmetic surgical procedures and the use of computer generated models to aid in the design. 5. The Senses: Skin Deep (FHS; 26 mins, 1984). It analyzes sensory receptors, taste buds, tactile sensors and olfactory cells. Written by a team of internationally recognized medical experts. The complex world beneath the skin is recreated.

Software 1. Practice Anatomy Lab™ 2.0: Anatomical Models, Histology (see full list on page 9 of this manual).

Copyright © 2010 Pearson Education, Inc.

61

62

Text and media guide to human anatomy and physiology

Materials to Improve Teaching Thumbnails of all figures in Chapter 5 can be found in Appendix B.

Index Instructor Slide/Resource DVD Image Image Image Image Image Image Image

5,1 5,2 5,3 5,4 5,5 5,6 5,7 5,8 5,9

Figure 5.10 Making Connections

skin texture. The main structural features of the skin epidermis. The two regions of the dermis. Dermal modifications lead to characteristic skin tags. skin glands. Structure of a hair and hair follicle. structure of a nail. Photographs of skin cancer. Estimate the extent and severity of burns using the rule of nine. Partial and full fire. Homeostatic interrelationships between the integumentary system and other body systems

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 13. The cells of the stratum spinosum are called spinous cells because of their pointed shape in fixed tissues; Keratohyalin granules and laminated granules occur in the cells of the stratum granulosum. (p. 150) 14. Usually not. Most "bald" men have fine hair that looks like peach fuzz in the "bald" areas. (p. 159) 15. On an extremely hot and sunny summer day, your skin system will work in several ways to maintain homeostasis. First, your skin will sweat. Sweating is a form of thermoregulation that prevents overheating by increasing blood flow to the skin and allowing it to release heat to the environment. Second, your melanocytes will start producing more melanin. The melanin granules are then delivered to the keratinocytes, where they protect the keratinocyte nucleus from the sun's harmful UV rays. (pp. 150, 161) 16. First degree burns affect only the epidermis; Second-degree burns reach the dermis; and third-degree burns affect the subcutaneous tissue and muscles. (pp. 163-165) 17. Hair formation begins with an active growth phase, followed by a resting phase. After the resting period, new hairs are formed to replace the old ones. Factors affecting growth cycles include diet, hormones, local skin perfusion, body region, gender, age, genetic factors, physical or emotional trauma, excessive radiation, and certain medications. Factors that affect hair texture include hormones, body region, genetic factors, and age. (p. 164) 18. Cyanosis is a condition in which the skin of Caucasians turns blue due to insufficiently oxygenated hemoglobin. (p. 155) 19. Wrinkles result from loss of skin elasticity along with loss of subcutaneous tissue and are accelerated by prolonged exposure to wind and sun. (p. 165)

Copyright © 2010 Pearson Education, Inc.

Chapter 5

The integumentary system

20. a. A whitehead is formed by blocking the duct of a sebaceous gland with sebum. When this sebum oxidizes, a blackhead is formed. When a blocked sebaceous gland becomes infected, a pimple develops. (p. 157) b. Non-infectious dandruff is the normal desquamation of the horny layer of the scalp. (p. 152) c. Oily hair and a shiny nose are the result of sebum secretion on the skin. (p. 156) d. Stretch marks represent small tears in the dermis when the skin is stretched due to obesity or pregnancy. (p. 153) d. A freckle is a small patch of pigment on the epidermis caused by a build-up of melanin. (p. 154) 21. (a) Porphyria. Porphyria victims lack the ability to produce Hb-heme. The accumulation of intermediate products (porphyrins) in the blood causes damage to sun-exposed skin. Dracula is said to have drunk blood and avoided daylight. (p. 168) 22. The cells of the stratum corneum are dead. By definition, cancer cells are rapidly dividing cells. (p. 152) 23. Nail shaft: The visible fixed part of the nail. Nail root: the embedded part of the nail. Nail bed: the epidermis that stretches under the nail. Nail Matrix: The thick proximal portion of the nail bed responsible for nail growth. Eponychium: the cuticle. If the matrix is ​​damaged, the nail may not grow back or may become distorted. In this case, the nail may not grow back because everything has been lost, including the matrix. (p. 160; Fig. 5.7) 24. See Fig. 5.9. (p. 163) (a) 18% rear trunk 4.5% (right buttock*) 4.5% (left buttock) 27%. *Buttocks are only approximately (b) Complete lower extremity 36% (c) Complete left front (anterior) upper extremity 4.5% 25. Hair consists of keratinized dead cells. Growth takes place in the hair follicle and is influenced by diet and hormones. Trimming dead hair does not affect follicle growth. (pp. 157, 159)

Critical Thinking Issues and Clinical Applications 1. Prolonged overexposure to ultraviolet radiation from sunlight is considered a risk factor for the development of skin cancer. In addition, birthmarks or pigmented spots that show asymmetry (A), marginal irregularity (B), color variation (C), and greater than 6 mm in diameter (D) are indicators of possible malignant melanoma. You should see a doctor immediately. If it is a malignant melanoma, the chance of survival is not high, but early detection increases the survival rate. (p. 163) 2. The two most important problems that arise clinically in a third degree burn victim are the loss of body fluids, leading to dehydration and electrolyte imbalance, and the risk of infection. Intact skin not only effectively blocks the diffusion of water and water-soluble substances from the body, but also acts as a barrier limiting the penetration of various microorganisms. (pp. 163-164) 3. Chronic physical irritation or inflammation can cause excessive hair growth in the affected region due to increased blood flow to the area. (p. 159) 4. The appendectomy incision ran parallel to the less dense "cleavage lines" that separate the collagen fiber bundles in the dermis. The gallbladder cut went right through her. (p. 153)

Reading recommendation Christensen, Damaris. "Hair today, will it be gone tomorrow?" Science News 160(16) (October 2001): 254–255.

Copyright © 2010 Pearson Education, Inc.

63

64

Text and Media Instructor's Guide to Human Anatomy and Physiology Garnick, Marc "Sunshine's D-lemma." Harvard Health Letter 3 (2008 August): 6-7. Glausiusz, Josie. "A Sunscreen for Our Sensitive Genes." Discover 22(3) (March 2001): 13. Gregoriou, Stamatis, et al. "Nail Disease and Systemic Illness: What Nails Tell Us". Journal of Family Practice 57 (August 2008): 509–514. Kara, Julia. "Skin so neat." Scientific American 284(3) (March 2001): 21. Kirchweger, Gina. "In black and white." Discover 22(2) (February 2001): 32–33. Krueger, James G. "Treatment of Psoriasis with Biologic Agents." Science and Medicine 8(3) (May/June 2002): 150–161. Nizet, V., et al. "The innate antimicrobial peptide protects the skin from invasive bacterial infections." Nature 414 (November 2001): 454–457. Pins, George D. "An analogue of the basal lamina." Science and Medicine 7(3) (2000): 6–7. Oxidation, Ricki L. "Hair: Why it grows, why it stops." Scientific American 284(6) (October 2001): 70–79. Travis, J. "Human sweat packs a germicidal punch." Science News 160(19) (November 2001): 292. Wright, Karen. Skeeter Scouts. Discover 22(8) (Aug 2001): 20–21.

Copyright © 2010 Pearson Education, Inc.

bone and skeletal tissue

Objectives Skeletal Cartilage 1. Describe the functional properties of the three types of cartilage. 2. Locate the major cartilages of the adult skeleton. 3. Explain how cartilage grows. Bone classification 4. Name the main regions of the skeleton and describe their respective functions. 5. Compare and contrast the structure of the four types of bones and give examples of each type. Bone Functions 6. List and describe five important bone functions. bone structure

6

9. Describe the histology of compact and cancellous bone. 10. Discuss the chemical composition of bones and the advantages of organic and inorganic components. Bone development 11. Compare and contrast intramembranous ossification and endochondral ossification. 12. Describe the growth process of long tubular bones at the epiphyseal plates. Bone Homeostasis: Remodeling and Repair 13. Compare the sites of remodeling and the functions of osteoblasts, osteocytes and osteoclasts. 14. Explain how hormones and physical stress regulate bone turnover. 15. Describe the steps involved in fracture repair. Bone homeostatic imbalances

7. Indicate the functional importance of bone markers. 8. Describe the rough anatomy of a typical long bone and a flat bone. Indicate the location and functions of the red and yellow marrow, articular cartilage, periosteum, and endosteum.

16. Compare the disorders of bone turnover observed in osteoporosis, osteomalacia and Paget's disease. Aspects of bone development: timing of events 17. Describe the timing and cause of changes in bone architecture and mass throughout life.

Suggested Structure of Lesson I. Skeletal Cartilage (p. 173; Fig. 6.1) A. Basic Structure, Types and Location (p. 173; Fig. 6.1) 1. Skeletal cartilage consists of cartilage surrounded by a dense layer of irregular connective tissue. Tissues called perichondrium. 2. Hyaline cartilage is the most common skeletal cartilage and includes articular, costal, respiratory and nasal cartilage. Copyright © 2010 Pearson Education, Inc. All rights reserved.

Sixty-five

66

Text and media Teacher's manual of human anatomy and physiology 3. Elastic cartilage is more flexible than hyaline cartilage and is found only in the external ear and epiglottis of the larynx. 4. Fibrous cartilage is found in areas that need to endure a lot of pressure or stretching, such as the B. Knee cartilage and intervertebral discs. B. Cartilage Growth (p. 173) 1. Appositional growth results in outward expansion due to the production of cartilage matrix on the outside of the tissue. 2. Interstitial growth leads to expansion into the cartilage matrix due to division of chondrocytes attached to the gaps and secretion from the matrix.

II. Classification of Bones (pp. 173-175; Figs. 6.1-6.2) A. There are two main divisions of bones in the skeleton: the axial skeleton, consisting of the skull, vertebral column, and thorax; and the appendix skeleton, consisting of the bones of the upper and lower limbs and the ligaments connecting them to the axial skeleton (pp. 173-174; Fig. 6.1). B. Shape (pp. 174-175; Fig. 6.2) 1. The long bones are longer than wide, have a distinct shaft and two ends, and consist of all the bones of the extremities except the patella, carpus, and tarsus. 2. The short bones are somewhat cubic in shape and include the carpus and tarsi. 3. Flat bones are thin, flat, and often curved bones that include most of the bones of the skull, sternum, shoulder blades, and ribs. 4. Irregular bones have complicated shapes that do not fit into any other class, such as vertebrae and femurs.

3. Functions of bones (pp. 175-176) A. Bones support the body and soft organs, protect vital organs, allow movement, store minerals such as calcium and phosphate, and house blood-forming tissue in certain bone cavities, the spinal cord (pp. 175-176 ).

4. Bone structure (pp. 176-182; Figs. 6.3-6.7; Table 6.1) A. Gross anatomy (pp. 176-178; Figs. 6.3, 6.5; Table 6.1) the surface of bones, which serve as attachment sites for muscles, Ligaments and tendons, acting as articular surfaces and as openings for the passage of blood vessels and nerves. 2. Bone structure: compact and spongy bone a. Each bone has a dense outer layer composed of compact bone that is smooth and firm to the touch. B. The bone inside the compact is cancellous bone composed of honeycombs, needles, or flat pieces called trabeculae. 3. Structure of a typical long bone a. Long bones have a tubular bone shaft consisting of a bony collar surrounding a hollow medullary cavity filled with yellow bone marrow in adults. B. The epiphyses are located at the ends of the bone and consist of inner cancellous bone covered by an outer layer of compact bone. C. The epiphyseal line lies between the epiphyses and the diaphysis and is a remnant of the epiphyseal plate.

Copyright © 2010 Pearson Education, Inc.

Chapter 6

bone and skeletal tissue

i.e. The outer surface of the bone is covered by the periosteum. Y. The inner surface of the bone is lined with a connective tissue membrane called the endosteum. 4. Structure of short, flat and irregular bones a. Short, flat, irregular bones consist of thin plates of compact bone covered with periosteum on the outside and cancellous bone covered with endosteum on the inside, enclosing the bone marrow between trabeculae. 5. Location of Hematopoietic Tissue in Bone a. The hematopoietic tissue of bone, the red bone marrow, is found in the trabecular cavities of the cancellous bone in flat bones and in the epiphyses of long bones. B. Red bone marrow is found in all flat bones, epiphyses, and medullary cavities in infants, but in adults, distribution is restricted to the flat bones and proximal epiphyses of the humerus and femur. B. Microscopic Anatomy of Bone (pp. 179-180; Figs. 6.3 to 6.7) 1. The structural unit of compact bone is the osteon or haversian system, which consists of concentric tubes of bone matrix (the lamellae) that form a havers - Bones surround. Canal that serves as a passage for blood vessels and nerves. a. The perforators or Volkmann canals lie at right angles to the long axis of the bone and connect the blood and nerve supply of the periosteum to the central canals and medullary cavity. B. Osteocytes occupy gaps at the junctions of the lamellae and are connected to each other and to the central canal by a series of hair-like canals called canaliculi. C. Circumferential lamellae lie just below the periosteum and extend around the entire circumference of the bone, while interstitial lamellae lie between intact osteons and fill in the interstices. 2. Cancellous bone has no osteons, but trabeculae that line up along the stress lines and contain irregular lamellae. C. Chemical Composition of Bone (p. 180) 1. The organic components of bone include cells (osteoblasts, osteocytes, and osteoclasts) and osteoids (ground substance and collagen fibers), which contribute to the flexibility and tensile strength of bone. 2. Inorganic components make up 65% of bone mass and consist of hydroxyapatite, a mineral salt composed mainly of calcium phosphate and responsible for the hardness and compressive strength of bones.

V. Bone development (pp. 182-185; Figs. 6.8-6.11) A. Formation of the bony skeleton (pp. 182-184; Figs. 6.8-6.9) gives rise to the bones of the skull and clavicles. 2. In endochondral ossification, bone tissue replaces hyaline cartilage and forms all bones below the skull except the clavicles. a. Initially, osteoblasts secrete osteoid and form a bony collar around the shaft of the hyaline cartilage model. B. The cartilage in the middle of the shaft calcifies and deteriorates, forming cavities.

Copyright © 2010 Pearson Education, Inc.

67

68

Text and media manual for instructors in human anatomy and physiology c. The periosteal bud penetrates the internal cavities and cancellous bone forms around the remaining fragments of hyaline cartilage. i.e. The shaft elongates as epiphyseal cartilage continues to elongate, and a medullary cavity is formed by the action of osteoclasts in the center of the shaft. Y. The epiphyses ossify soon after birth by the development of secondary centers of ossification. B. Postnatal bone growth (pp. 184 and 185; Figs. 6.10 and 6.11) 1. Long bones grow in length in the ossification zone through rapid division of the upper cells in the chondrocyte columns, calcification and bone resorption. .Cartilage at the base of the columns and subsequent replacement by bone tissue. 2. The increase in width or thickness occurs by appositional growth due to the deposition of bone matrix by osteoblasts under the periosteum. 3. Hormonal regulation of bone growth a. During childhood, the major stimulus for epiphyseal activity is growth hormone from the anterior pituitary, the action of which is modulated by thyroid hormone. B. During puberty, testosterone and estrogen promote a growth spurt but eventually induce closure of the epiphyseal plate.

SEEN. Bone homeostasis: remodeling and repair (pp. 185-190; Figs. 6.11-6.15; Table 6.2) A. Bone remodeling (pp. 185-188; Figs. 6.11-6.13) Withdrawal bone; Bone deposition occurs to a greater extent when the bone is injured; and bone resorption releases minerals from the degraded bone matrix into the blood. 2. Control of the reform a. The hormonal mechanism is mainly used to maintain calcium homeostasis in the blood and to balance the activity of parathyroid hormone and calcitonin. B. In response to mechanical stress and gravity, bone grows or remodels in a way that allows it to withstand the loads it is subjected to. B. Bone reconstruction (pp. 188-190; Fig. 6.15; Table 6.2) 1. Fractures are fractures in the bones and are classified according to: the position of the bone ends after the fracture, the integrity of the fracture, the orientation of the fracture in relation to the long axis of the bone and whether the bone ends penetrate the skin. 2. Fracture healing includes four major stages: hematoma formation, fibrocartilaginous callus formation, bone callus formation, and bone callus remodeling.

VIII. Bone Homeostatic Imbalance (pp. 189-191, 194; Fig. 6.16) A. Osteomalacia and Rickets (p. 189) 1. Osteomalacia encompasses a variety of disorders in adults in which the bone is not adequately mineralized. 2. Rickets is insufficient bone mineralization in children caused by calcium or vitamin D deficiency B. Osteoporosis refers to a group of diseases in which the rate of bone loss exceeds the rate of bone formation (pp. 189-191, Fig. 6.16). 1. Bones have normal bone matrix, but bone mass is reduced and bones become more porous and lighter, increasing the likelihood of fractures. Copyright © 2010 Pearson Education, Inc.

Chapter 6

bone and skeletal tissue

2. Older women are particularly prone to osteoporosis due to the drop in estrogen after menopause. 3. Other factors that contribute to osteoporosis are a small stature, insufficient exercise or immobility, a diet low in calcium and vitamin D, abnormal vitamin D receptors, smoking and certain hormonal disorders. C. Paget's disease is characterized by excessive bone deposition and resorption, resulting in abnormally high cancellous bone. It is a localized condition that results in deformation of the affected bone (pp. 191, 194).

VIII. Aspects of Bone Development: Timing of Events (p. 194; Fig. 6.17) A. The skeleton is derived from embryonic mesenchymal cells and ossification occurs at well-defined times. Most long bones have primary centers of ossification which are evident at 12 weeks gestation (p. 194). B. At birth most bones are well ossified except for the epiphyses which form secondary centers of ossification (p. 194). C. Bone growth exceeds bone resorption throughout childhood; in young adults these processes are in balance; in old age, absorption outweighs formation (p. 194).

Cross-references For more information on the topics covered in Chapter 6, see the chapters listed below. 1. Chapter 2: Calcium Salts 2. Chapter 4: Bones (bone tissue); chondroblasts; collagen fibers; fibroblasts; fibrocartilage; hyaline cartilage; Proteoglycans 3. Chapter 7: Individual bones that make up the skeleton; Identifying Characteristics of Individual Bones 4. Chapter 8: Articular Cartilage and Joint Structure 5. Chapter 16: Giantism and Dwarfism Associated with Bone Growth and Length; Effects of Parathyroid Hormone and Calcitonin on Bone Homeostasis 6. Chapter 17: Hematopoietic Tissue

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 9: Skeletal Overview: Bone and Cartilage Classification and Structure 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 9: Skeletal Overview: Bone and Cartilage Classification and Structure

Teaching Tips 1. Students often mistakenly distinguish between long and short bones based on size. Emphasize that the distinction is based on shape, not size. 2. Emphasize the difference between the epiphyseal plate and the epiphyseal line.

Copyright © 2010 Pearson Education, Inc.

69

70

Text and Media Human Anatomy and Physiology Teacher Guide 3. Emphasize that the perichondrium does not cover the articular cartilage. 4. Emphasize the difference between red and yellow bone marrow. 5. Point out that the osteocytes in Haversian systems are not isolated from each other but are connected by tubules. 6. Compare and contrast the position and function of osteocytes, osteoblasts and osteoclasts. 7. Point out that women (18 years) stop growing long bones earlier than men (21 years). 8. Emphasize that bones can remodel or grow through apposition even after length growth is complete. 9. Point out that greenstick fractures are more common in children because their bones contain more organic matrix and are more flexible. 10. Distinguish between simple (closed) and compound (open) fractures. 11. Emphasize that bones must be subjected to mechanical stress to remain healthy. Physical activity pulls on bones, resulting in increased structure. Inactivity causes bone atrophy.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. As an analogy, hold up a bundle of raw spaghetti to illustrate the arrangement of osteons within the compact bone. 3. Break a green rod to illustrate a green rod break. Then contrast with a dry branch. 4. Get a long bone cut, such as B. a femur to illustrate the main parts of a bone. A freshly cut bone can be used to illustrate the periosteum and the difference between red and yellow bone marrow. 5. Obtain a fetal skeleton to illustrate the early stages of bone development. 6. Illustrate the chemical nature of bone tissue by placing one chicken bone in nitric acid and another in an oven. The nitric acid will leach out the calcium salts and the furnace will break down the organic matter. 7. Take x-rays of young children, adolescents, and adults to show changes in the epiphyseal plate. 8. Take x-rays of different types of fractures. If possible, have X-rays taken to show the healing stages after the fracture. 9. Create a 3D model of a Haversian system to illustrate the microscopic features of the bone. 10. Obtain a clean porcine embryo stained to show development of bone tissue (Carolina Biological Supply Company).

Critical Thinking/Points for Discussion 1. Examine the statement, "Multiple pregnancies result in the mother losing all of the enamel from her teeth and calcium from her bones." Is this all true, all false, or only partially true? 2. Make a list of hormonal abnormalities that can affect bone growth in both children and adults. 3. Can air pollution affect bone development? There? 4. Calcium plays an important role in bone formation. What other roles does calcium play in the body? Copyright © 2010 Pearson Education, Inc.

Chapter 6

bone and skeletal tissue

5. Full contact sports appear to be part of the curriculum for primary school aged children. Does this make sense from a bone development perspective? 6. The remains of prehistoric animals consist almost entirely of bones and teeth. There? 7. If the bone tissue is so hard, how can we move the teeth from one place to another in the jaw? 8. Why is infection more common in open fractures than in simple fractures? 9. How would prolonged weightlessness affect the skeletal system? How can these effects be minimized or at least reduced?

Library Research Topics 1. Find out about the latest technology, such as B. the Ilizarov procedure, used to lengthen bones damaged by accident or disease. 2. What does a bone marrow transplant involve? Is it a risky and difficult procedure? 3. What medications or treatments are available to correct the conditions of giant stature and dwarfism and how do they work? 4. Examine the procedures used in bone tissue transplants, in which pieces of bone are removed from one part of the body and implanted in another. 5. What effect would steroid use have on bone tissue and bone marrow? 6. How are electric fields used to stimulate bone growth and repair?

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all chapter-specific online media resources for Chapter 6 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 6.1 Skeletal cartilage (p. 173) Section 6.2 Bone classification (pp. 173-175) Section 6.3 Bone functions (pp. 175-176) Section 6.4 Bone structure (pp. 176-182) Artist Tagged: Structure a long bone (Fig. 6.3, p. 176) Artist's caption: Microscopic anatomy of compact bone (Fig. 6.7, p. 181) Memory game: The architecture of bone Memory game: Cartilage and bone structure Section 6.5 Bone development (p. 181 )–185) Section 6.6 Bone Homeostasis: Remodeling and Repair (pp. 185-190) MP3 Tutor Session: Calcium Regulation MP3 Tutor Session: How Bones Respond to Stress Section 6.7 Bone Homeostatic Imbalance (pp. 189-191)

Copyright © 2010 Pearson Education, Inc.

71

72

Text and Media Teacher's Guide to Human Anatomy and Physiology Section 6.8 Aspects of Bone Development: Timing of Events (p. 194) Chapter Summary Crosswords 6.1 Crosswords 6.2 Web Links Chapter Tests Art Labeling Quiz Art Combination Quiz Quiz True-False Multiple Choice Quiz Chapter Practice Test Study Tools Histology- Atlas myeBook Flashcards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Slides 1. Common connective tissue (WNS) slide set

Video 1. Bone marrow transplants (FHS; 28 min, 1990). Provides an overview of the most advanced techniques in bone marrow transplantation. Viewers are taken to the University of Washington Medical Center, known for its work in bone marrow transplants. 2. Bones and Joints (FHS; 20 min, 1995). Part of The New Living Body series, this video covers movement, joint structure and function, bone growth, and the effects of movement on bones. 3. Osteoporosis: new treatments for bone loss (FHS; 23 min, 2000). This program describes the symptoms of osteoporosis and emphasizes the importance of good nutrition and regular exercise as preventive measures.

Software 1. Practice Anatomy Lab™ 2.0: Human Cadaver, Histology (see full list on page 9 of this manual). 2. WARD Radiographic Anatomy (WNS; Windows) (see page 9 of this manual for a complete list).

Material to improve the lesson Thumbnails of all illustrations in Chapter 6 can be found in Appendix B.

Copyright © 2010 Pearson Education, Inc.

Chapter 6

bone and skeletal tissue

Index Instructor Slide/Resource DVD Image Image Image Image Image

6,1 6,2 6,3 6,4 6,5

Figure 6.6 Figure 6.7 Figure 6.8 Figure 6.9 Figure 6.10 Figure 6.11 Figure 6.12 Figure 6.13 Figure 6.14 Figure 6.15 Figure 6.16 Figure 6.17 Table 6.1 Table 6.2 Make connections

The bones and cartilage of the human skeleton. Classification of bones according to their shape. The structure of a long bone (humerus of the arm). Comparison of different types of bone cells. Flat bones consist of a layer of cancellous bone sandwiched between two thin layers of compact bone. A single osteon. Microscopic anatomy of compact bone. intramembranous ossification. Endochondral ossification in a long bone. Long bones grow in length at the epiphyseal plate. Growth and remodeling of long bones during adolescence. Parathyroid hormone (PTH) control of blood calcium levels. Bone anatomy and bending stress. Vigorous exercise can lead to a large increase in bone strength. Stages of healing a broken bone. The contrasting architecture of normal vs. osteoporotic bone. Fetal primary ossification centers at 12 weeks. Bone Marks Common Types of Fractures Homeostatic Interrelationships Between the Skeletal System and Other Body Systems

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 15. Cartilage is more resilient because its matrix lacks bone salts, but its cells receive nutrients from the cartilage by diffusion of blood vessels. On the other hand, the bone has a system of beautifully designed canals to supply nutrients and therefore regenerates much faster and more completely. (pp. 173, 179-180) 16. a. A collar of bone is placed around the shaft of the hyaline cartilage model. B. The cartilage in the middle of the shaft calcifies and then develops caries. C. The periosteal bud penetrates the internal cavities and forms spongiosa. i.e. The diaphysis is lengthened and a medullary cavity is formed. Y. The epiphyses ossify. (pp. 183-184) 17. The Volkmann's canals extend through the bone matrix and connect the central canal, the periosteum and all the lamellae. The canaliculi connect all the lacunae and allow the transfer of nutrients and waste between the blood and the osteocytes. (p. 179) 18. The increase in thickness of the compact bone on its superficial surface is compensated by bone resorption by osteoclasts on its inner surface. (pp. 185-186) 19. An osteoid suture is an unmineralized band of bone matrix about 10-12 microns wide. There is an abrupt transition between this junction and the older bone called the calcification front. The osteoid suture is always the same width, suggesting this

Copyright © 2010 Pearson Education, Inc.

73

74

Human anatomy and physiology Texts and media Teacher's guide Osteoid tissue must mature before it can calcify. This area then rapidly changes from an unmineralized to a mineralized matrix. (p. 186) 20. Two control circuits regulate bone turnover. One is a hormonal negative feedback mechanism that keeps Ca2+ in the blood and the other involves mechanical and gravitational forces acting on the skeleton. (p. 186) 21. a. The first decade is the fastest; the fourth decade is the slowest. (p. 194) b. Older people often suffer from bone loss, osteoporosis and an increasing lack of blood circulation. (p. 191) c. Boys have proportionately more organic matrix. (p. 190) 22. This bone section is taken from the trial shaft. The presence of an osteon, the concentric layers surrounding a central cavity, indicates compact bone in the diaphysis. The epiphyseal plate, the site of active bone growth, lacks osteons. (pp. 179, 181)

Critical Thinking Questions and Clinical Application 1. A bony callus represents the transformation of a fibrocartilaginous callus into a callus containing trabeculae of cancellous bone. (p. 189) 2. Rickets. Milk provides dietary calcium and vitamin D. Vitamin D is needed for absorption by intestinal cells; the sun helps the skin synthesize vitamin D. Thick epiphyseal plates indicate poor calcification of the growth zone. Due to this lack of calcium, the bones become more flexible and load-bearing bones, such as those in the leg, bend. (p. 189) 3. The compact lamellar structure of dense bone creates structural units designed to resist torsion and other mechanical loads applied to the bone. In contrast, cancellous bone consists of trabeculae with only a few layers of thick cells containing irregularly arranged lamellae. (p. 187) 4. Since changes during adolescence include changes in stress associated with muscle growth and sex steroids, which in part affect bone deposition, a lack of bone remodeling during adolescence would keep bones in good shape. . Bone would retain a thinner, less dense appearance than would normally be expected, particularly in areas of increased stress. (pp. 185-187) 5. According to Wolff's law, bone growth and remodeling occurs in response to loads applied to these bones. When not in use, the bones in the unused extremities begin to atrophy. (p. 187) 6. The connection between the epiphyseal plate and the bone has probably come loose. This would not happen with the sister of the 23-year-old boy, since at this age the epiphyseal plates have been replaced by bone and are no longer present. (p. 185) 7. Paget's disease, which results in irregular thickening of bone tissue and often affects the skull and spine, causing pain and deformity. (p. 191)

Suggested Reading Arron, Joseph R. and Yongwon Choi. "Bone system versus immune system". Nature 408 (6792) (2000 Jul): 535-536. Hahn, B.H. and the. Mazzaferri. "Glucocorticoid-induced osteoporosis". Hospital Practice 30 (August 1995): 45–56. Hollander, A., S. Dickinson, T. Sims, et al. "Bioengineered tissue implants regenerate damaged cartilage in the knee." Tissue Engineering 12 (2006 Jul): 1787–1798.

Copyright © 2010 Pearson Education, Inc.

Chapter 6

bone and skeletal tissue

Jukes, J., S. Both, A. Leusink, L. Sterk, C. van Blitterswijk, and J. de Boer. "Engineering of endochondral bone tissue using embryonic stem cells". PNAS 105 (May 2008): 6840-6845. Kotz, Rainer I., et al. "A self-expanding pediatric leg implant". Nature 406 (6792) (July 2000): 143. Manolagas, S.C. "Birth and death of bone cells: basic regulatory mechanisms and implications for the pathogenesis and treatment of osteoporosis". Endocrine Reviews 21 (2000): 115-137. Quarto R, Mastrogiacomo M, Canchedda R, et al. "Repair of large bone defects using autologous bone marrow stromal cells". New England Journal of Medicine 344 (February 2001): 385-386. Riggs, B.L. "A New Option for the Treatment of Osteoporosis." New England Journal of Medicine 327 (July 1990): 124-125. Rubin, C., AS. Turner, S. Bain, C. Mallinckrodt, and K. McLeod. "Low mechanical signals strengthen long bones." Nature 412 (6847) (2001 Aug): 604. Sarrel, P.M., et al. "Estrogen Effects on the Arteries, Bones and the Brain". Scientific American: Science and Medicine (July/August 1994): 44.

Copyright © 2010 Pearson Education, Inc.

75

7

the skeleton

Goals

PART 2: OR APPENDAGE SKELETON TO SHOULDER BELT

PART 1: THE AXIAL SKELETON 1. Name the main parts of the axial and cecal skeletons and describe their respective functions. The Skull 2. Name, describe, and identify the bones of the skull. Identify your important tags. 3. Compare and contrast the main features of the skull and facial skeleton. 4. Define the bony borders of the orbits, nasal cavity and paranasal sinuses. The spine 5. Describe the structure of the spine, list its components and describe its curvatures. 6. Name a common function of the curvatures of the spine and intervertebral discs. 7. Discuss the structure of a typical vertebra and describe the regional characteristics of the cervical, thoracic and lumbar vertebrae. thorax

10. Identify the bones that make up the shoulder girdle and relate their structure and arrangement to the function of the shoulder girdle. 11. Identify major bony landmarks on the shoulder girdle. The Upper Limb 12. Identify or name the bones of the upper limb and their important features. The pelvic girdle (hip) 13. Name the bones that contribute to the thighs and match the strength of the pelvic girdle to its function. 14. Describe the differences in the male and female pelvis and relate them to functional differences. The Lower Limbs 15. Identify the bones of the lower limbs and their important markers. 16. Name the arches of the feet and explain their importance. aspects of skeletal development

8. Name and describe the bones of the chest (bony thorax). 9. Distinguish the real ribs from the fake ones.

17. Define fontanelles and give their meaning. 18. Describe how the proportions of the skeleton change throughout life. 19. Discuss how age-related skeletal changes can affect health.

76 Copyright © 2010 Pearson Education, Inc.

Chapter 7

the skeleton

Suggested Lesson Plan PART 1: THE AXIAL SKELETON I. The Skull (pp. 199-216; Figs. 7.1-7.15; Table 7.1) A. The skull consists of 22 cranial and facial bones that form the framework of the face, it contains cavities for special sense organs, provide openings for the passage of air and food, protect teeth, and anchor facial muscles (p. 200). B. With the exception of the lower jaw, which is attached to the skull by a movable joint, most of the skull's bones are flat bones held together by interlocking connections called sutures (p. 200). C. General description of the geography of the skull (p. 200) 1. The anterior surface of the skull is formed by the facial bones and the rest is formed by a skull divided into the calvaria or calvaria and the base of the skull skull. 2. The cranial cavities include the cranial cavity (which contains the brain), the ear cavities, the nasal cavity, and the orbital cavities (which contain the eyeballs). 3. The skull has about 85 named openings that provide passageways for the spinal cord, the large blood vessels that supply the brain, and the cranial nerves. D. The skull consists of eight strong, upwardly curved bones (pp. 199-209; Figs. 7.2-7.10). 1. The frontal bone articulates posteriorly with the parietal bones via the coronal suture, extends anteriorly to the supraorbital margins, and extends posteriorly to form the superior wall of the orbits and most of the anterior cranial fossa. 2. The parietal bones are two large rectangular bones on the top and sides of the skull that make up most of the cranial vault. a. The four main sutures of the skull are where the parietal bones articulate with other bones: the coronal, sagittal, lambda, and squamous sutures. 3. The occiput articulates with the parietal, temporal, and sphenoid bones and forms most of the posterior wall and base of the skull. a. The foramen magnum, a large opening that connects the brain to the spinal cord, is located at the base of the occipital bone. 4. The temporal bones articulate with the parietal bones and form the inferolateral surfaces of the skull and parts of the cranial floor. a. The temporal bone is characterized by the mandibular fossa, which is part of the temporomandibular joint, and the petrous and external auditory canals, which house the ear. 5. The sphenoid extends across the width of the middle cranial fossa and articulates with all the other cranial bones. 6. The ethmoid lies between the sphenoid and nasal bones and forms most of the bony area between the nasal cavity and the orbits. 7. Suture or worm bones are irregularly shaped groups of bones or groups of bones located within sutures that vary in number and are not present in all skulls.

Copyright © 2010 Pearson Education, Inc.

77

78

E. Facial bones (pp. 209–211; Fig. 7.11) 1. The mandible or mandible articulates with the mandibular fossae of the temporal bones via the jaws of the condyles to form the temporomandibular joint in common. 2. The maxillary bones form the upper jaw and central part of the face and articulate with all other facial bones except the lower jaw. 3. The cheekbones articulate with the temporal, frontal, and maxillary bones, forming the cheekbones and portions of the inferolateral margins of the orbits. 4. The nasal bones form the bridge of the nose and articulate with the frontal, maxillary and ethmoid bones and cartilages, which make up most of the external nasal skeleton. 5. The lacrimal bones are located on the medial wall of the orbits and articulate with the frontal, ethmoid, and maxillary bones. 6. The palatine bones consist of bony plates that complete the posterior part of the hard palate, form part of the posterolateral walls of the nasal cavity, and small parts of the orbits. 7. The vomer is located in the nasal cavity where it forms part of the nasal septum. 8. The inferior turbinates are thin, curved bones of the nasal cavity that protrude medially from the lateral walls of the nasal cavity. F. The hyoid bone lies below the lower jaw at the front of the neck. It is the only bone that does not articulate directly with any other bone (p. 211; Fig. 7.12). G. Features of the Orbits and Nasal Cavities (pp. 211-216; Fig. 7.13) 1. The orbits are bony cavities that contain the eyes, the muscles that move the eyes, and the lacrimal glands. They consist of the frontal, sphenoid, zygomatic, maxillary, palatine, lacrimal, and ethmoid bones. 2. The nasal cavity is made of bone and hyaline cartilage and consists of the ethmoid, maxilla and palatine bones, and the inferior turbinates. It is divided into right and left parts by the nasal septum, which consists of parts of the ethmoid and vomer bones. H. The paranasal sinuses are air-filled sinuses that cluster around the nasal cavity, illuminating the skull and increasing the resonance of the voice (p. 216; Figs. 7.14-7.15).

II. The Vertebral Column (pp. 216-221; Figs. 7.16-7.21; Table 7.2) A. General Characteristics (pp. 216-218; Figs. 7.16-7.17) 1. The vertebral column consists of 26 irregular bones forming a flexible , curved structure that extends from the skull to the pelvis that surrounds and protects the spinal cord. It provides attachment for the ribs and muscles of the neck and back. 2. Splits and curvatures a. The vertebrae of the spine are divided into five major divisions: seven cervical vertebrae, twelve thoracic vertebrae, five lumbar vertebrae, five fused sacral vertebrae, and four fused coccygeal vertebrae. B. Curves in the spine increase the strength and flexibility of the spine. C. The cervical and lumbar curves are concave posteriorly, and the thoracic and sacral curves are convex posteriorly. 3. The most important supportive ligaments of the spine are the front and rear longitudinal ligaments, which run as continuous ligaments in front and behind.

Copyright © 2010 Pearson Education, Inc.

Chapter 7

the skeleton

posterior surfaces of the spine. They support the spine and prevent hyperflexion and hyperextension. 4. Intervertebral discs are cushion-like pads that act as shock absorbers, allowing the spine to flex, extend, and bend laterally. B. General structure of the vertebrae (p. 219; Fig. 7.18) 1. Each vertebra consists of an anterior vertebral body and a posterior vertebral arch, which together with the vertebral body form the vertebral foramen through which the spinal cord passes. 2. The vertebral arch consists of two pedicles and two laminae, which together form several projections: a median spinous process, two lateral transverse processes, and two superior and inferior articular processes. 3. The pedicles have notches on their upper and lower edges called intervertebral foramina that provide openings for the passage of spinal nerves. C. Regional vertebral features (pp. 219-223; Figs. 7.19-7.21; Table 7.2) 1. The cervical vertebrae are the smallest vertebrae. They usually have an oval body, a short bifurcated spinous process, a large triangular vertebral foramen and a transverse foramen. a. The atlas has no body or spinous process. It has articular facets on the top and bottom that articulate with the skull above and the second cervical vertebra, the axis, below. B. The second cervical vertebra has a typical body, vertebral column and other vertebral processes, and a knob-shaped cavity or tooth process that protrudes upward from the body. 2. All thoracic vertebrae articulate with the ribs, making a gradual transition between the cervical spine above and the lumbar spine below. a. The thoracic vertebrae have a roughly heart-shaped body with two facets on each side for rib articulation: a circular vertebral hole and superior and inferior articular processes. 3. The lumbar vertebrae are large vertebrae with kidney-shaped bodies, a triangular foramen, short, thick pedicles and laminae, and short, flat, hatchet-shaped spinous processes. 4. The sacrum forms the posterior wall of the pelvis. It consists of five fused vertebrae in adults and articulates with the fifth lumbar vertebra above, the coccyx below, and the hip bones laterally through the sacroiliac joint. a. The spinal canal continues through the sacrum and usually ends in a large external opening, the hiatus sacralis. 5. The coccyx (coccyx) is a small bone composed of four fused vertebrae that articulate upward with the sacrum.

3. The rib cage (pp. 223-225; Figs. 7.22-7.23) A. The rib cage consists of the thoracic vertebrae dorsally, the ribs laterally, and the sternum and costal cartilages in front. It forms a protective covering around the organs in the thoracic cavity and supports the shoulder girdle and upper extremities (pp. 223-224; Fig. 7.22). B. Sternum (pp. 223-224; Fig. 7.22) 1. The sternum (breastbone) lies in the anterior midline of the thorax and is a flat bone formed from the fusion of three bones: the manubrium, trunk, and the sternum the xiphoid process.

Copyright © 2010 Pearson Education, Inc.

79

80

Text and media Teacher's manual of human anatomy and physiology 2. The manubrium articulates with the clavicles and the first two pairs of ribs. The body articulates with the cartilages of ribs two through seven. The xiphoid process forms the lower limb and articulates only with the body. C. Ribs (pp. 224-225; Figs. 7.22-7.23) 1. The sides of the thorax are formed by twelve pairs of ribs that attach at the back of the thoracic vertebrae and curve down toward the front surface of the body. 2. The top seven pairs of ribs are called the true or vertebrosternal ribs. They are attached directly to the sternum via individual costal cartilages. 3. The bottom five pairs of ribs are called false ribs. They are indirectly attached to the sternum or have no sternal attachment at all.

PART 2: THE APPENDAGES SKELETON IV. The Shoulder Girdle (pp. 225-228; Figs. 7.24-7.25; Table 7.3) A. The shoulder (thoracic) girdle consists of the collarbone, which attaches in front of the sternum, and the scapula, which attaches to the back of the chest and to the vertebrae. .by muscle attachments (pp. 225-226; Fig. 7.24). 1. The shoulder girdle is very light and has high mobility due to the openness of the shoulder joint and the free movement of the scapula along the rib cage. B. The clavicles (collarbones) extend horizontally across the rib cage, articulate medially with the sternum and laterally with the scapula, and laterally support the arms and shoulder blades (p. 226; Fig. 7.24). C. The scapulae (shoulder blades) are thin, flat bones that lie on the dorsal surface of the rib cage and articulate with the humerus through the glenoid fossa and the clavicle through the acromion (pp. 226-228; Fig. 7.25).

V. The Upper Limb (pp. 228-233; Figs. 7.26-7.28; Tab. 7.3) A. Arm (p. 228; Fig. 7.26) 1. The upper arm is the region extending from the shoulder to the elbow extends and has one bone, the humerus. 2. The humerus is the largest and longest bone of the upper extremity. It articulates with the scapula at the shoulder and with the radius and ulna at the elbow. B. Forearm (pp. 228-231; Fig. 7.27) 1. The forearm is the region between the elbow and the wrist. It consists of two bones, the ulna and the radius. 2. The ulna forms the elbow joint with the humerus. It articulates laterally with the radius at the proximal end and articulates with the carpal bones via a cartilaginous disc at the distal end. 3. The radius articulates medially with the humerus and ulna at the proximal end through a flattened head. It articulates with the carpal bones of the wrist and the ulna medially at the distal end. C. Hand (pp. 231-233; Fig. 7.28) 1. The carpus (wrist) consists of eight short bones arranged in two irregular rows of four bones each: scaphoid, lunate, triquetrum and proximal pisiform; and the trapezium, trapezoidal, large and distally hamate. 2. The metacarpal (palm) consists of five small long bones numbered one through five from the thumb to the little finger. It articulates proximally with the carpals and distally with the proximal phalanges. Copyright © 2010 Pearson Education, Inc.

Chapter 7

the skeleton

3. There are 14 phalanges of the fingers: The thumb (pollex) is number 1 and has two phalanges. The other fingers, numbered 2 through 5, each have three phalanxes.

SEEN. The pelvic girdle (hip girdle) (pp. 233-237; Figs. 7.29-7.30; Tables 7.4-7.5) A. The pelvic girdle connects the lower extremities to the axial skeleton. It is formed by a pair of femurs, each consisting of three separate bones: ischium, ilium, and pubis, which are fused together in the adult (pp. 233-235; Fig. 7.29). B. The ilium forms the upper portion of the hip bone. It articulates with the sacrum and forms the sacroiliac joint, as well as with the ischium and anterior pubis (pp. 234-235; Figs. 7.29-7.30). C. The ischium forms the posteroinferior portion of the thigh (pp. 234-235; Figs. 7.29-7.30). D. The pubic bones form the front part of the thighs. They are connected by a disc of fibrocartilage and form the median symphysis pubis (pp. 234-235; Figs. 7.29-7.30). E. Pelvic Structure and Pregnancy (pp. 235-237; Box 7.4) 1. The female pelvis is modified for pregnancy. It tends to be wider, shallower, lighter and more rounded than the male pelvis. 2. The pelvis consists of a false pelvis, which is part of the abdomen and helps support the bowels, and a real pelvis, which is completely surrounded by bone and contains the pelvic organs.

VIII. The Lower Limb (pp. 237-241; Figs. 7.31-7.34; Table 7.5) A. Thigh (p. 237; Fig. 7.31) 1. The thigh is the region between the hip and the knee. It has one bone, the femur. 2. The femur is the largest, longest, and strongest bone in the body. It articulates proximally with the hip through a ball head and distally with the knee at the lateral and medial condyles. 3. The patella is a triangular sesamoid bone that articulates with the femur on the patellar surface. B. Leg (pp. 237-240; Fig. 7.32) 1. The leg is the region between the knee and the ankle. It has two bones, the tibia and fibula. 2. The tibia is the bone that supports the weight of the leg. It is characterized proximally by the medial and lateral condyles that articulate with the femur, and distally by the medial malleolus, an inferior protrusion on the medial surface that articulates with the talus. 3. The fibula is a rod-shaped bone that does not support weight. It has flared ends that articulate with the lateral surfaces of the tibia proximally through the head and distally through the lateral malleolus. C. Foot (pp. 240-241; Figs. 7.33 and 7.34) 1. The tarsal consists of seven tarsal bones which form the posterior half of the foot and includes the calcaneus, talus, cuboid, scaphoid and medial, the intermediate and tarsal bones sides of the sphenoid bones. 2. The metatarsus is made up of five small, long bones called the metatarsal bones, numbered 1 through 5, that begin on the medial side of the foot. 3. The fingers have 14 phalanxes: The big toe (hallux) is the first toe and has two phalanxes. The other fingers, numbered 2 through 5, each have three phalanxes.

Copyright © 2010 Pearson Education, Inc.

81

82

Text and Media Teacher's Manual of Human Anatomy and Physiology 4. The arch of the foot is maintained by the interlocking of foot bones, ligaments, and tendons during muscular activity.

VIII. Aspects of skeletal development (pp. 242-244; Figs. 7.35-7.38) A. Towards the end of the second month of development, the bones of the skull begin to ossify (p. 242). B. At birth, the skull bones are connected by fontanelles, unossified remnants of fibrous membranes (p. 242; Fig. 7.35). C. Changes in craniofacial proportions and fusion of bones occur in childhood (p. 243; Fig. 7.33). 1. At birth, the skull is much larger than the face and many of the bones are not yet fused together. 2. At nine months, the skull is half the size of an adult due to rapid brain growth. 3. By the age of 8-9 years, the skull reaches almost adult proportions. 4. Between the ages of 6 and 13, the jaw, cheekbones and nose become more prominent due to the expansion of the nose, paranasal sinuses and the development of permanent teeth. D. Curves of the Spine (pp. 243-244; Fig. 7.37) 1. The primary curves (sternal and sacral) are posteriorly convex and present at birth. 2. The secondary curves (cervical and lumbar) are anteriorly convex and are related to the child's development. 3. Secondary curvatures result from remodeling of the intervertebral discs. E. Changes in height and body proportions occur throughout childhood (p. 244; Fig. 7.38). 1. At birth, the head and trunk are approximately 1.5 times the length of the lower limbs. 2. The lower limbs grow faster than the trunk, and by the age of 10 the head and trunk are about the same length as the lower limbs. 3. During puberty, the female pelvis expands and the male skeleton becomes more robust. F. Effects of age on the skeleton (p. 244). 1. The discs become thinner, less hydrated and less elastic. 2. The chest becomes stiffer due to calcification of the costal cartilages. 3. All bones lose bone mass.

Cross-references For more information on the topics discussed in Chapter 7, refer to the chapters listed below. 1st 2nd 3rd 4th

Chapter Chapter Chapter Chapter Muscles Muscles Chapter 5 Chapter 6

4: fibrocartilage; hyaline cartilage 6: bony markers; Bone classification 8: joints; Sutures 10: strengthening the spinal muscles; facial muscles; of the thorax; muscles of the upper extremities; pelvic girdle muscles; of the lower extremity 15: Bones of the middle ear cavity 22: Bones of the skull with a function in the respiratory system

Copyright © 2010 Pearson Education, Inc.

Chapter 7

the skeleton

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 10: The axial skeleton Exercise 11: The appendicular skeleton Exercise 12: The fetal skeleton 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 10: The axial skeleton Exercise 11: The appendix skeleton Exercise 12: The fetal skeleton

Teaching Tips 1. A good indicator of students' understanding of the spatial relationship between the facial bones is the ability to list the bones that make up the eye socket. 2. Point out in the class that the styloid process of the temporal bone is often damaged during skeletal preparation. As a result, the skulls available in the lab may not have this fragile structure. 3. Students often have difficulty identifying the sphenoid and ethmoid bones. It would be useful to show disarticulated specimens during the lecture. 4. Point out that all facial bones (except the lower jaw) articulate with the upper jaw. 5. Remembering shared meal times, 7:00 am, 12:00 pm, and 5:00 pm, can help students remember the number of bones in the three regions of the spine. 6. Atlas supports the world can be used to help students remember that the atlas is the first and second axis. 7. Point out that the correct anatomical terminology “arm” is the part between the shoulder and the elbow; and "leg" refers to the section between the knee and the ankle. 8. Although the obturator foramen is large, it is actually closed by a fibrous membrane in living. 9. In anatomical position, the radius/ulna and fibula/tibia are arranged in alphabetical order from the outside.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. The skull is remarkably strong for its weight and the thinness of the skull bones. This is partly due to the curvature of the skull, a "self-reinforcing" effect. To demonstrate this effect, try cracking an egg by pressing it in your (or a student's) palm. 3. Give a group of students a thoracic vertebra and a rib and ask them to articulate them together. 4. Tie a different colored string around the lamina and pedicle of a vertebra and share it with the class to help students identify these structures. 5. Use an articulated skeleton to display its protective and supportive aspects and identify individual bones. 6. Obtain a skull with the skull cut out and a spine to illustrate how these bones protect sensitive neural tissue. 7. Get a skull with worm bones. 8. Use a Beauchene skull (disarticulated) to demonstrate the individual bones of the skull and show the fragile internal structure of the bones that contain the sinuses.

Copyright © 2010 Pearson Education, Inc.

83

84

Text and Media Human Anatomy & Physiology - Teacher's Guide 9. Use a disarticulated spine to illustrate the similarities/differences between the vertebrae. 10. Point out that the superior articular surface of the atlas is elongated and conforms to the surface of the occipital condyle. 11. Take X-rays that show abnormal curvatures (scoliosis, lordosis, kyphosis). 12. Obtain different ribs and indicate how they are similar and different. 13. Point out the differences between the male and female pelvis. 14. Obtain a sacrum to show the fusion of the vertebrae. 15. Use a fetal skeleton to emphasize the changes in skull and body proportions after birth and to indicate that the skeleton is originally (mainly) hyaline cartilage and not bone.

Critical Thinking/Points for Discussion 1. List several skeletal landmarks that can assist a nurse or physician in administering injections, locating surgical sites, and assisting in diagnosing internal disorders. 2. What effect would excessive exercise or no exercise have on bones such as the tibia, femur, and humerus if it occurred in childhood? in adulthood? 3. Many children are born with a birth defect in the hip. Why is this area affected so often and what can be done to correct the defect? 4. Years ago, students would carry large, heavy books on one arm or the other. Nowadays most students use backpacks. What difference, if any, could be identified between then and now in the spine? 5. Various religious scriptures indicate that a rib was taken from man to create woman. Are ribs missing on the male rib cage? What could explain this discrepancy? 6. Humans have short necks, but giraffes have long necks. Does the giraffe have more cervical vertebrae to accommodate that extra length? What other similarities or differences are there between human bone structure and that of other animals? 7. How can you “taste” the drops right after putting them in your eyes? 8. Why does the lower lip go numb when a dentist injects novocaine near the mandibular foramen?

Library Research Topics 1. There is a technique known as Automated Percutaneous Discectomy which is a seamless operation on the back. How safe is it and when can it be used? 2. Temporomandibular joint disorders are very common and painful. What treatment methods are there and how successful are they? 3. Deviations of the spine, such as B. scoliosis, are very difficult to repair. What are the current treatment methods, both invasive and non-invasive? 4. Paleontologists and archaeologists have unearthed many prehistoric skulls and bones of humanoid creatures and animals. How can they reconstruct the features and soft tissues of these animals from their skeletal remains alone? 5. Trace the origin of congenital diseases such as spina bifida and cleft palate, starting with the human embryo. What is the explanation for these shortcomings?

Copyright © 2010 Pearson Education, Inc.

Chapter 7

the skeleton

6. Surgery to repair a herniated disc may require removal of part of the nucleus pulposus. Removal can be by conventional surgery or by chemonuclease. What are the advantages of the latter method?

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all chapter-specific online media resources for Chapter 7 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives PART 1: THE AXIAL SKELETON Section 7.1 The Skull (pp. 199-216) Artist's Caption: Anterior Skull Anatomy (Fig. 7.4a, p. 202) Artist's Caption: Lateral Skull Bones, External View (Fig. 7.5a, p. 203). ) Artist's caption: Lateral skull bones, internal view (Fig. 7.5b, p. 203) Artist's caption: Lower side of the skull, lower jaw removed (Fig. 7.6a, p. 205) Artist's caption: The floor of the cranial cavity (Fig. 7.7a, p 206) Art labeling: bones of the nasal cavity (Fig. 7.14a–b, p. 213) Section 7.2 The spine (pp. 216–221) ) Section 7.3 The rib cage (pp. 223–225) Memory game: identification of the Components of the axial skeleton PART 2: THE APPENDIX SKELETON Memory game: Identifying the bones of the appendicular skeleton Section 7.4 The waist pectoralis (shoulder) (pp. 225-228) Art label: Shoulder girdle and clavicle (Fig. 7.24, p. 226) Art label: The scapula (Figs. 7.25a–b, p. 227) Section 7.5 The upper extr ety (p. 228) –233) Art Labelling: The humerus of the right arm (Fig. 7:26a–b, p. 229) Art Labelling: Radius and ulna of the right forearm (Fig. 7.27a–b, p. 230) Artist Label: Bones of the left hand (Fig. 7.28, p. 231) Section 7.6 The pelvic girdle (hip ) (pp. 233–237) Artist label: articular pelvis (Fig. 7.29, p. 231) . 233) Artist Label: Pelvic Bone (Figs. 7.30a–b, p. 234) Section 7.7 The Lower Limb (pp. 237–241) Artist Label: Right Femur (Fig. 7.31b, p. 238 ) Artist Label: Tibia and Fibula of the right leg (Figs. 7.32a–b, p. 239) Artist's label: Bones of the right foot, plan view (Fig. 7.33a, p. 240) Artist's label: Bones of the right foot Foot, medial and lateral views (Fig. 7.33b –c, p. 240) Chapter 7.8 Aspects of skeletal development (pp. 242–244)

Copyright © 2010 Pearson Education, Inc.

85

86

Text and Media Human Anatomy and Physiology Teacher's Guide Chapter Summary Bones Review Crosswords 7.1 Crosswords 7.2 Web Links Chapter Quizzes Art Labeling Quiz Matching Quiz Multiple Choice Quiz True False Quiz Chapter Quiz Study Tools Histology Atlas myeBook Flashcards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1. Anatomy of the Hand (FHS; 15 min, 1999). This program demonstrates how the hand works and highlights the opposable nature of the thumb. 2. Anatomy of the Shoulder (FHS; 17 min, 1999). This program introduces the technical specifications of the shoulder: what muscles are involved, how it works, and its range of motion. Various diseases are discussed. 3. Artificial Body Parts (FHS; 26 min., 1990). This program will showcase the latest advances in medical technology. It shows the latest information on research into blood vessel transplants and joint and limb replacements. 4. Bones and Muscles (FHS; 15 min, 1996). This program features a visit to a pharmaceutical company to discuss new treatments for osteoporosis. 5. Our Flexible Framework: The Muscular and Skeletal Systems Video (WNS; 20 min). Animated graphics illustrate essential functions of the skeletal system, such as protecting internal organs, producing blood cells and providing attachment points for muscles. 6. Leg Extension (FHS; 45 mins). Experts explain problems related to the anatomical function of the patient's leg. They also discuss how the surgery will improve the patient's quality of life. 7. The skeletal system (IM; 27 min., 2005). This DVD describes the human skeletal system. It identifies the bones of the human body and teaches you to locate each bone.

Copyright © 2010 Pearson Education, Inc.

Chapter 7

the skeleton

(Video) How Do Your Body Parts Work? | Non Stop Episodes | The Dr. Binocs Show | PEEKABOO KIDZ

8. Skeletal System: The Infrastructure (IM; 30 min., 1998). This DVD explains how the skeletal and muscular systems work together to enable movement and provide the body with much needed structure, protection and support. He talks about the joints and describes the role of the skeletal system in the production of blood cells.

Software 1. A.D.A.M.® Anatomy Practice 4.0 (ADAM, BC; Win/Mac, 1999). It allows students to review thousands of solid structures in hundreds of anatomical images. Images and associated notes can be printed out for review. Includes a lab-like still image test mode. 2. A.D.A.M.® Interactive Anatomy® (see page 9 of this manual for a complete list). 3. A.D.A.M.® MediaPro 4.0 (see page 9 of this manual for a complete list). 4. Practice Anatomy Lab™ 2.0: Human Cadaver Anatomical Models (See page 9 of this guide for a complete list). 5. The Ultimate Human Body, version 2.2 (see page 9 of this manual for the full list).

Material to improve the lesson Thumbnails of all illustrations in Chapter 7 can be found in Appendix B.

Index Instructor Slide/Resource DVD Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure

7,1 7,2 7,3 7,4 7,5 7,6 7,7 7,8 7,9 7,10 7,11 7,12 7,13 7,14 7,15 7,16 7, 17 7,18 7,19 7,20 7,21 7,22 7,23 7,24 7,25 7,26

The human skeleton. The skull: cranial and facial departments and pits. Main skull cavities, frontal section. Anatomy of the anterior and posterior surfaces of the skull. Bones of the lateral sides of the skull, external and internal views. Underside of skull, lower jaw removed. The floor of the skull cavity. The temporal bone. The sphenoid. The ethmoid. Detailed anatomy of the lower and upper jaw. The hyoid bone, anterior view. Bones that form the orbits. bones of the nasal cavity. paranasal sinuses. the spine. Fibrocartilage Ligaments and discs that attach the vertebrae. Structure of a typical vortex. The first and second cervical vertebrae. Posterolateral views of the articulated vertebrae. sacrum and coccyx. The chest. ribs. pectoral girdle and collarbone. The scapula. The humerus of the right arm and detailed views of the elbow joint. Copyright © 2010 Pearson Education, Inc.

87

88

Figure 7.27 Figure 7.28 Figure 7.29 Figure 7.30 Figure 7.31 Figure 7.32 Figure 7.33 Figure 7.34 Figure 7.35 Figure 7.36 Figure 7.37 Figure 7.38

Radius and cubit of the right forearm. bones of the left hand. Articulated pelvis with the two hip bones (which together form the pelvic girdle), the sacrum and the coccyx. bones of the bony pelvis. Bones of the right knee and thigh. Tibia and fibula of the right leg. bones of the right foot. standing arches. Skull of a newborn. A baby was born with a cleft lip. The C-shaped spine of a newborn. The different growth rates of the body parts determine the proportions of the body. Skull bones Regional features of the cervical, thoracic and lumbar vertebrae Bones of the appendix part 1: shoulder girdle and upper extremity Comparison of male and female pelvis Bones of the appendix part 2: pelvic girdle and lower extremity

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Briefly answer development questions 4. Skull bones: parietal, temporal, frontal, occipital, sphenoid and ethmoid. Facial Bones: Mandible, vomer, maxilla, cheekbone, nasal, lacrimal, palatine and inferior turbinate. The bones of the skull provide attachment points and surround and protect the brain. The facial bones form the structure of the face, hold the eyes in place, provide cavities for the organs of taste and smell, protect the teeth, and anchor the facial muscles. (pp. 200-211; Table 7.1) 5. At birth the skull is huge in relation to the facial skeleton. During childhood and adolescence, the face grows out of the skull. In adulthood, the cranial and facial skeletons are of reasonable size. (p. 243) 6. The normal curves are: cervical, thoracic, lumbar and sacral. Sternum and sacrum are primary; cervical and lumbar are secondary. (pp. 216-217) 7. Cervical vertebrae have transverse foramina, small bodies, and bifurcated spinous processes; Thoracic vertebrae have rib facets and circular vertebral foramina; The lumbar vertebrae have massive bodies and blunt spines. (pp. 219-220; Table 7.2) 8. The discs act as shock absorbers, allowing the spine to bend and straighten (provides flexibility). (p. 218) 9. The annulus fibrosus, composed of fibrocartilage, is the outermost and contains the nucleus pulposus. The nucleus is the semi-liquid substance enclosed by the ring. The ring provides strength and durability. The core provides resilience. In a herniated disc, the nucleus pulposus protrudes through the annulus. (p. 218) 10. a. Real rib: attached directly at both ends; False rib: connected directly to the vertebrae, indirectly to the sternum.

Copyright © 2010 Pearson Education, Inc.

Chapter 7

11

12

13

14

fifteen.

the skeleton

B. A floating rib is a false rib. (p. 224) The function of the pelvic girdle supports and transfers body weight to the lower extremities. The bones are large, strong, and firmly connect the femurs to the axial skeleton. The bones of the pectoral girdle are light and fairly flexible to provide flexibility at the expense of strength and stability. (pp. 225, 233) The entrance and exit of the female pelvis are wider; the pelvis is shallower, lighter and rounder than that of the male; and the seat bones are further apart. (p. 235; Table 7.4) Both cleft palate and hip dysplasia are congenital anomalies that impair skeletal formation. A cleft palate occurs when midline fusion of the maxilla does not occur. Problems can range from a simple cosmetic abnormality to a total lack of separation between the nasal and oral cavities. In this case, the infant has difficulty swallowing food and may even aspirate because there is no palate to regulate breathing and swallowing. Hip dysplasia occurs when the acetabulum cannot properly form a complete socket around the ball of the femur, or when the ligaments that attach the femur to the hip are too loose. The femur can easily slip out of its socket, making walking difficult. (p. 243) In the skeleton of a young adult, the bone mass is dense, the water content in the intervertebral discs is normal, and the spine is strong. With age, the intervertebral discs lose water content and become thinner and less elastic, the spine shortens and arches, and all bones lose mass. The thorax stiffens with age, mainly due to ossification of the costal cartilage. The bones of the skull lose less mass than most bones with age, but the facial contours of older people change. (p. 244) Peter had a little fun with the obturator foramen, the large opening in the hip bone through which some blood vessels and nerves pass. (p. 235)

Critical Thinking Questions and Clinical Application 1. Justiniano likely has carpal tunnel syndrome, a nerve disorder common in people who repeatedly flex their wrists and fingers, often at a computer keyboard. (p. 231) 2. A lateral curve is a scoliosis that results from uneven muscle pulls. Because the muscles on one side of the body weren't working, those on the opposite side pulled harder, forcing the spine into alignment. (p. 217) 3. Femoral neck fractures, often referred to as hip fractures, are common in the elderly due to osteoporosis, which particularly weakens the vertebrae and femoral neck. (p. 237) 4. Mrs. Shea developed pain in her buttocks in response to having her full weight on the point of the buttocks for three days. If he continued this activity for a few more days, he would develop pressure sores called bedsores. (p. 235)

Suggested Reading Agur, A.M. and A.F. Dalley. Grant's Atlas of Anatomy. 12th ed. Baltimore: Lippincott Williams & Wilkins, 2009. Chase, R.A. The Bassett Atlas of Human Anatomy. San Francisco: Benjamin Cummings, 1989. Clemente, C.D. Anatomy: A regional atlas of the human body. 5th ed. Baltimore: Lippincott Williams & Wilkins, 2007.

Copyright © 2010 Pearson Education, Inc.

89

90

Text and Media Instructor's Guide to Human Anatomy and Physiology Gordon, K.R. "Adaptive Nature of Skeletal Design." BioScience 39 (December 1989): 784-790. Gray, H., et al. Grey's anatomy. 39th Edition London: Churchill Livingstone, 2005. Newschwander, G.E., et al. "Limb Lengthening with Llizaron External Fixator." Orthopedic Nursing 8 (May-June 1989): 15–21.

Copyright © 2010 Pearson Education, Inc.

joints

Objectives Classification of joints 1. Define articulation or articulation. 2. Classify joints structurally and functionally. Fiber joints 3. Describe the general structure of fiber joints. Name and give an example of each of the three most common types of fiber joints. Cartilaginous joints 4. Describe the general structure of cartilaginous joints. Name and give an example of each of the two most common types of cartilaginous joints. Synovial joints 5. Describe the structural features of the synovial joints. 6. Compare the structures and functions of the bursae and tendon sheaths. 7. Name three natural factors that stabilize synovial joints.

8

8. Name and describe (or perform) general types of body movements. 9. Name and give examples of the six types of synovial joints according to the type of movement allowed. 10. Describe the elbow, knee, hip, jaw and shoulder joints in terms of joint bones, anatomical features of the joint, allowable movements and stability of the joint. Homeostatic imbalance of the joints 11. List the most common joint lesions and discuss the associated symptoms and problems. 12. Compare and distinguish common types of arthritis. 13. Describe the cause and consequences of Lyme disease. Aspects of joint development 14. Discuss the factors that promote or alter joint homeostasis.

Suggested Lesson Plan I. Classification of joints (pp. 248-249; Figures 8-1 to 8.3; Table 8.1) A. Structural classification focuses on the material holding bones together and whether or not there is a joint cavity (p. 249; Table 8.1). 1. In fibrous joints, the bones are held together by fibrous tissue and have no joint cavity. 2. In cartilaginous joints, the bones are held together by cartilage and have no joint cavity. 3. In synovial joints, the articulating bones are separated by a fluid-filled joint cavity.

91 Copyright © 2010 Pearson Education, Inc.

92

Text and media Teacher's manual of human anatomy and physiology B. Functional classification is based on the amount of movement permitted in the joint (p. 249). 1. Synarthrosis are immobile joints. 2. Amphiarthrosis are small movable joints. 3. Diarthrosis are joints that move freely.

II. Fibrous joints (pp. 249-250; Fig. 8.1; Tables 8.1-8.2) A. The sutures are located between the cranial bones and hold the bones together with very short connective tissue fibers (p. 249; Fig. 8.1 ). ) B. In syndesmosis the bones are joined by a ligament, which is a cord or band of fibrous tissue (pp. 249-250; Fig. 8.1). C. A gomhose is a fibrous alveolar joint (p. 250; Fig. 8.1).

3. Cartilaginous joints (pp. 250-251; Fig. 8.2; Tables 8.1-8.2) A. The synchondrosis is a rod or plate of hyaline cartilage that connects the bones, such as the epiphyseal plate (pp. 250- 251; Fig. 8.2). ). B. In the pubic symphysis, such as the pubic symphysis, the articular surfaces are covered with articular cartilage, which then fuses with an intermediate pad or plate of fibrocartilage (p. 251; Fig. 8.2).

4. Synovial Joints (pp. 251-269; Figs. 8.3-8.8, 8.10-8.13; Tables 8.1-8.2) A. The general structure of a synovial joint has five distinguishing features (pp. 251-252; Fig. 8.3). 1. Articular cartilage covers the ends of the joint bones. 2. The articular (synovial) cavity is a space filled with synovial fluid. 3. The two-layer joint capsule surrounds the joint cavity. 4. Synovial fluid is a slippery, viscous fluid that fills all of the free space in the joint cavity. 5. Stiffening ligaments cross the synovial joints to strengthen the joint. B. Tendon bursa and tendon sheaths are pockets of lubricant that reduce friction in synovial joints (p. 252; Fig. 8.4). C. Factors Affecting the Stability of Synovial Joints (pp. 252-254) 1. The shapes of the articular surfaces of the bones found in a synovial joint determine, but play a role at least in, the movements that occur in the joint of stabilization The joint. 2. The ligaments in a synovial joint prevent excessive or unwanted movement and help stabilize the joint; The more ligaments there are in the joint, the greater the stability. 3. Muscle tone keeps the tendons crossing the joints taut, which is the most important factor in joint stabilization. D. Movements Allowed by the Synovial Joints (pp. 254-259; Figs. 8.5-8.6; Table 8.2) 1. In gliding movements, one flat or nearly flat bone surface slides or slides over another. 2. Angular movements increase or decrease the angle between two bones. a. Flexion decreases the angle of the joint and brings the articulating bones closer together. B. Extension increases the angle between the articulating bones.

Copyright © 2010 Pearson Education, Inc.

Chapter 8 c. Dorsiflexion decreases the angle between the top of the foot (dorsal surface) and the front surface of the tibia. i.e. Plantar flexion decreases the angle between the sole of the foot (plantar surface) and the back of the tibia. Y. Abduction is the movement of a limb (or finger) away from the midline of the body (or hand). F. Adduction is the movement of a limb (or finger) toward the midline of the body (or hand). Grams. Circumduction moves a limb so that it describes a cone in the air. 3. Rotation is the turning of a bone around its own axis. 4. Special Moves a. In supination, the forearm is rotated sideways so the palm faces forward or up. B. Pronation rotates the arm medially so that the palm faces back or down. C. Inversion rotates the sole of the foot toward the center. i.e. Eversion turns the sole of the foot so that it points to the side. Y. Protraction moves the mandible forward and projects the mandible forward. F. Retraction returns the lower jaw to its original position. Grams. Elevation means lifting a part of the body higher. h Depression means moving a raised body part down. ME. The opposition occurs when you touch your thumb with the fingers of the same hand. E. Types of synovial joints (p. 259; Fig. 8.7; Table 8.2) 1. Planar joints have planar articular surfaces and allow for gliding and transitional movements. 2. Hinged joints consist of a cylindrical protrusion embedded in a channel-like structure, allowing movement along a single plane. 3. Articulation joints consist of a rounded structure projecting into a sleeve or ring that allows uniaxial rotation of a bone about the long axis. 4. Condyloid or ellipsoid joints consist of an oval articular surface that nestles in a complementary cavity and allows all angular movement. 5. Saddle joints consist of each articular surface with complementary concave and convex areas and allow more freedom of movement than condyloid joints. 6. Patellas consist of a spherical or hemispherical structure that articulates with a cup-shaped structure. They are the joints that move more freely and allow for multi-axis movement. F. Selected synovial joints (pp. 259–269; Figs. 8.8, 8.10–8.13) 1. Knee joint a. Enclosed in a joint cavity, the knee joint is actually three joints in one: the patellofemoral joint, the lateral and medial joints between the femoral condyles, and the tibial menisci, collectively known as the tibiofemoral joint. B. Many different types of ligaments stabilize and strengthen the joint capsule of the knee. C. The knee capsule is strengthened by muscle tendons such as the strong tendons of the quadriceps muscles and the semimembranosus tendon.

Copyright © 2010 Pearson Education, Inc.

joints

93

94

Text and media Human anatomy and physiology Teacher's manual 2. Elbow joint a. The elbow joint provides a smooth, stable joint that allows only flexion and extension. B. The ligaments involved in stabilizing the elbow joint are the annular ligament, the ulnar collateral ligament, and the radial collateral ligament. C. The tendons of several arm muscles, the biceps and triceps, also provide additional stability at the elbow joint. 3. Shoulder joint (glenohumeral) a. Stability has been sacrificed to provide the most flexible joint in the body. B. The ligaments that help strengthen the shoulder joint are the coracohumeral ligament and the three glenohumeral ligaments. C. The tendons that cross the shoulder joint and have the greatest stabilizing effect on the joint are the long head tendon of the biceps brachii and the four tendons that make up the rotator cuff. 4. Hip joint (coxal) a. The hip joint is a ball and socket joint, which offers good freedom of movement. B. Several strong ligaments reinforce the capsule of the hip joint. C. The tendons of the muscles crossing the joint contribute to the stability and strength of the joint, but most of the stability of the hip joint is due to the deep socket of the acetabulum and ligaments. 5. TMJ a. The temporomandibular joint allows for both hinge movements and side-to-side lateral movements. B. The joint contains a disc that divides the synovial cavity into compartments that support each type of movement. C. The lateral surface of the fibrous capsule contains a collateral ligament that strengthens the joint.

V. Homeostatic Imbalance of Joints (pp. 269-271; Figs. 8.9, 8.14-8.15) A. Common Joint Injuries (pp. 269-270; Figs. 8.9, 8.14) 1. Sprains occur when the ligaments supporting a joint are stretched or torn. 2. Cartilage tears usually occur in the knee when a meniscus is subjected to pressure and shear at the same time. 3. Dislocations occur when bones become out of alignment. B. Inflammatory and Degenerative Conditions (pp. 270-271; Fig. 8.15) 1. Bursitis, an inflammation of the bursa, is usually caused by a blow or friction; Tendonitis is inflammation of the tendons and is usually caused by overuse. 2. Arthritis describes many inflammatory or degenerative diseases that damage the joints and cause pain, stiffness and swelling in the joints. a. Osteoarthritis is the most common chronic arthritis. It is the result of the breakdown of joint cartilage and subsequent thickening of bone tissue, which can limit joint movement. B. Rheumatoid arthritis is a chronic inflammatory disease that is an autoimmune disease.

Copyright © 2010 Pearson Education, Inc.

Chapter 8 c. Gouty arthritis occurs when uric acid builds up in the soft tissues of the joints. i.e. Lyme disease is an inflammatory disease caused by a type of spirochete bacteria that is transmitted through the bite of ticks that live on deer and mice.

SEEN. Aspects of joint development (p. 272) A. Joints develop at the same time as bones and resemble the adult form up to the eighth week of gestation (p. 272). B. In late middle age and beyond, ligaments and tendons shorten and weaken, intervertebral discs become more prone to hernia, and osteoarthritis begins (p. 272).

Cross-references For more information on the topics covered in Chapter 8, see the chapters listed below. 1. Chapter 1: Body levels 2. Chapter 4: Ligaments and tendons (dense connective tissue); hyaline cartilage; Fibrous cartilage 3. Chapter 6: Epiphyseal plate; articular cartilage; periosteum 4. Chapter 7: intervertebral discs; Stability/flexibility of the shoulder girdle 5. Chapter 10: Role of synovial joints in body movement 6. Chapter 23: Periodontal ligament

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 13: Joints and body movements 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 13: Joints and Body Movements

Teaching Tips 1. Distinguish clearly between the two common classification systems (structural and functional). 2. Highlight the difference between the joint of the first rib and the sternum as opposed to ribs 2 through 10. 3. Emphasize that a muscle must cross a joint to produce movement. 4. Compare and contrast the size and shape of the glenoid fossa and acetabulum. 5. When examining a single synovial joint in detail, the best option is the knee. 6. Emphasize the relationship between the shape of a joint's articulating surfaces and the types of motion that are possible at that joint. 7. Explain the importance of the synovial fluid in the joint capsule to maintain the pressure that dampens movement. Also point out that excess accumulation of this fluid, as part of the inflammatory response, helps immobilize a joint somewhat after injury.

Copyright © 2010 Pearson Education, Inc.

joints

95

96

Text and media guide to human anatomy and physiology

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Ask students to demonstrate the different types of body movements: abduction, adduction, flexion, extension, etc. that occur at specific joints (e.g., knee flexion, hand rotation). 3. Obtain an articulated skeleton to represent joints such as sutures, syndesmoses, gomphoses and others. 4. Create a 3D model of a joint, e.g. B. the knee to illustrate the relationship between ligaments, cartilage and muscles. A fresh beef shank can also be used. 5. Take x-rays of patients with gouty arthritis, osteoarthritis and rheumatoid arthritis. 6. Obtain a video or ask a local orthopedist to attend the class and describe the techniques and benefits of arthroscopic knee surgery. 7. Take an x-ray showing a prosthetic joint.

Critical Thinking/Points for Discussion 1. Why is diarthrosis predominantly found in the extremities, while synarthrosis and amphiarthrosis are predominantly found in the axial skeleton? 2. What are the advantages of the shoulder joint as the most flexible joint in the body? 3. Cortisone injections can easily reduce swelling that occurs in joints like shoulders and knees after sports injuries. Why is it dangerous for athletes to continue receiving these injections? 4. Physiotherapists suggest various stretching exercises before proceeding with rigorous physical activity. How important are these exercises for joint areas? 5. What does it mean to be "double jointed"? 6. Most people can "snap" their fingers. What does this term mean and what effects will it have on the joints in the future? 7. Bones appear to have numerous protrusions and projections. What do you think they are for?

Library Research Topics 1. Joints can often be injured during sports activities. What are the main joint injuries associated with football, basketball, baseball and tennis? 2. Congenital dislocation of the hip is an orthopedic defect in which the acetabulum is too shallow and as a result the femoral head becomes disarticulated. What is the current treatment for this defect? 3. It is becoming increasingly common to replace a damaged joint with an artificial one. Which seals can currently be replaced? 4. Disorders of the temporomandibular joint are very painful. What treatment methods are there and how successful are they? How do these joint diseases develop? 5. There is much controversy surrounding the use of the drug dimethyl sulfoxide (DMSO). Why is the FDA so reluctant to give this drug full approval for human use when it is widely used in horses? 6. Contact your local orthopedic surgeon for information and/or videos on arthroscopic surgery.

Copyright © 2010 Pearson Education, Inc.

Chapter 8 7. Review the literature on procedures and materials used for artificial joint replacement. 8. Rheumatoid arthritis appears to be an autoimmune disease. What are the current treatment methods and what is the future prognosis of this disease and its cure? 9. What is the difference between the action of nonsteroidal anti-inflammatory drugs and steroid anti-inflammatory drugs? What are the pros and cons of each?

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all chapter-specific online media resources for Chapter 8 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 8.1 Classification of joints (pages 248-249) MP3 Tutor Session: Types of joints and their movements Section 8.2 Fibrous joints (pages 249-250) Section 8.3 Cartilaginous joints (pages 250-251) Section 8.4 Synovial joints (pages 251-269) Memory game: Synovial joint movements Memory game: Types of joints Section 8.5 Homeostatic imbalance of joints (pp. 269-271) Case study: joints Case study: craniosynotosis Section 8.6 Aspects of joint development Joints (p. 272) Chapter summary Crossword 8.1 Crossword 8.2 Web links Chapter Quiz Art Lettering Quiz Matching Quiz Multiple Choice Quiz Chapter Practice Quiz Study Tools Histology Atlas myeBook Flashcards Glossary

Copyright © 2010 Pearson Education, Inc.

joints

97

98

Text and media guide to human anatomy and physiology

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1. Anatomy of the ankle and foot (FHS; 17 min, 1999). This program examines surface features and deeper features of the foot and ankle, emphasizing key bones, muscles, ligaments, blood vessels and nerves. 2. Arthroscopic Knee Surgery (FHS; 45 min). Bowman Gray School of Medicine physician Gary Poehling replaces a torn ACL with an Achilles tendon harvested from a cadaver from a donor pool. The operation is performed through arthroscopic visualization. 3. Bones and Joints (FHS; 20 min). From the series The New Living Body. It contains live-action videos showing the human body in action, actual images and three-dimensional computer graphics. Students can really see how the pieces work together to allow for movement. Illustrations of difficult concepts help students understand a lot. This is an excellent addition to classroom presentations. 4. Movements in the joints of the body (FHS; 39 min, 1997). This program, divided into three parts, demonstrates various body movements. The first part focuses on the movement, the second part examines muscle actions and the third part presents a self-assessment. 5. Moving Parts (FHS; 28 min, 1984). This program analyzes the coordination and balance mechanisms of activity. It shows how muscles, joints and organs are connected and shows the role of the joints. Improves students' knowledge of how body parts work together to create movement.

A.D.A.M.® Anatomy Practice Software (see page 87 of this manual for a complete list). A.D.A.M.® Interactive Anatomy® 4.0 (see page 9 of this manual for a complete list). A.D.A.M.® MediaPro (see page 9 of this manual for a complete list). Practice Anatomy Lab™ 2.0: Human Cadaver Anatomical Models (full list on page 9 of this manual). 5. The Ultimate Human Body, version 2.2 (see page 9 of this manual for the full list).

1. 2. 3. 4.

Materials to Improve Teaching Thumbnails of all the figures in Chapter 8 can be found in Appendix B.

Index Instructor Slide/Resource DVD Image Image Image Image

8,1 8,2 8,3 8,4

Fibrous joints. cartilaginous joints. General structure of a synovial joint. Bursae and tendon sheaths.

Copyright © 2010 Pearson Education, Inc.

Chapter 8 Figure 8.5 Figure 8.6 Figure 8.7 Figure 8.8 Figure 8.9 Figure 8.10 Figure 8.11 Figure 8.12 Figure 8.13 Figure 8.14 Figure 8.15 Table 8.1 Table 8.2 A closer look

Movements allowed by the synovial joints. Special body movements. Types of synovial joints. The knee joint. A common knee injury. The shoulder joint. The elbow joint. The hip joint. The temporomandibular joint (jaw). Arthroscopic view of a torn medial meniscus. X-ray of a hand deformed by rheumatoid arthritis. Summary of Joint Classes Structural and Functional Characteristics of Joints in the Body Joints: From Knight in Shining Armor to Bionic Man

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 8. Joints are defined as places where two or more bones meet. (p. 248) 9. Free-moving joints ensure mobility; easy-flexing joints provide strength with limited flexibility; Immovable joints provide strong support, secure containment and protection. (p. 249) 10. Bursae are membrane-lined joint sacs that prevent friction and are located where ligaments, muscles, skin, and/or muscle tendons overlap and rub against bone. In the latter case, the friction-reducing structures are called tendon sheaths. (p. 252) 11. Non-axial motion means sliding motion only, uniaxial motion means motion in one plane, biaxial motion means motion in two planes, and multi-axis motion means motion in or about all three planes and axes. (p. 253) 12. Flexion and extension refer to the decrease or increase in angle of a joint and the approach of the two joint bones along the sagittal plane, while adduction and abduction refer to the approach or removal of a joint. of the body along the frontal plane. (p. 255) 13. Rotation means to twist a bone about its own axis, while circumduction means to move a limb so that it describes a cone in space, an action involving a variety of movements. (p. 256) 14. Uniaxial: hinge (elbow) and pivot (atlantoaxial and radioulnar); biaxial: condyloid (ankle) and sella turcica (thumb); multiaxial: ball joint (shoulder and hip). (p. 259) 15. The menisci of the knee deepen the articular surface of the tibia to prevent lateral rocking of the femur on the tibia and to absorb shock transmitted to the knee joint. The cruciate ligaments prevent anterior/posterior displacement of the joint bone and help protect the joint. (pp. 262-264) 16. The knees must support the total weight of the body and rely heavily on non-articular factors for stability. The knees can absorb high-intensity upward force; they are supposed to absorb direct and lateral hits, but they are poorly designed for this. (p. 262)

Copyright © 2010 Pearson Education, Inc.

joints

99

100

Text and media Teacher's manual of human anatomy and physiology 17. Cartilage and ligaments are poorly vascularized and heal very slowly. (p. 264) 18. Composed of dense, irregular connective tissue, the fibrous capsule is the outer layer of the joint capsule (articular capsule) and strengthens the joint so that the bones do not separate. Synovial fluid occupies all free spaces within the joint capsule, including within the articular cartilage, and serves to reduce friction between the cartilages. Synovial fluid also contains phagocytes that remove microbes or cellular debris from the joint cavity. Articular cartilage is a smooth vitreous cartilage that covers opposing bone surfaces. These thin, spongy pads absorb the pressure exerted on the joint and prevent the bone ends from being crushed. (p. 251)

Questions of critical thinking and clinical application 1. Most likely bursitis of the subcutaneous prepatellar bursa. It's a good guess that Sophie spends a lot of time on her knees (perhaps scrubbing floors). (p. 270) 2. a. To be honest no. The shape of the articular surfaces is not as closed as in other joints and has greater flexibility because the joint is made up of three bones, not two. Also, there are relatively few strong muscles and ligaments crossing this joint compared to other joints like the hip or knee. (p. 262) b. Ligaments that hold bones together. (p. 262) c. Put the bones back in place without cutting. (p. 270) d. Sprains heal slowly and must be repaired to stabilize the joint. (p. 270) e. Examination of a joint through an endoscope. (p. 269) Q. Arthroscopic surgery requires only small incisions rather than an open surgical wound. There is less risk of infection and healing is significantly faster. (p. 269) 3. a. Probably gout, although it's more common in men. B. caused by the deposition of uric acid crystals in the soft tissues of the joints. (p. 271) 4. The vector of the bacterium that causes Lyme disease is the deer tick, a very small tick carried by deer and other small mammals. (p. 271) 5. As Tony's mouth opened wide, the mandibular condyle slid forward to the point where the joint was dislocated. (p. 268)

Suggested Reading Allman, W.F. "Knee". Science 83 (November 1983). De Bari, C., F. Dell'Accio, J. Vanlauwe, et al. "Mesenchymal Multipotency of Adult Human Periosteal Cells Evidenced by Single Cell Line Analysis". Arthritis and Rheumatism 54 (March 2006): 1209-1221. Fackelmann, K. A. "Chicken cartilage soothes aching joints." Science News 144 (Sept. 1993): 198. Fackelmann, K.A. "The Nine-Month Arthritis Cure." Science News 144 (October 1993): 144. Germain, BC Anatomy of Movement: Exercises (Revised ed.). Eastland Press, 2007. Gunn, C. Bones and Joints: A Guide for Students. 5th ed. London: Churchill Livingstone, 2008. Kantor, F.S. Disarming Lyme Disease. Scientific American 271 (September 1994): 34. Matsumoto, I., et al. "Arthritis Caused by Recognition of a Glycolytic Enzyme by Connected T and B Cells". Science 286 (November 1999): 1732–1735.

Copyright © 2010 Pearson Education, Inc.

Chapter 8 Mayors, M. B. and J. Collier. "A Quadril Substitution Technology." Scientific American: Science and Medicine 1 (May/June 1994): 58-67. Seppa, N. "Peptide brings mouse arthritis out of joint". Science News 159 (18) (May 2001): 279. Terkeltaub RA "Gout: Fresh Insights into an Ancient Disease." Scientific American: Science and Medicine 3 (July/August 1996): 22. Wang L. "Fat Harbors Cells That Could Aid Joints.” Science News 159(9) (March 2001): 134.

Copyright © 2010 Pearson Education, Inc.

joints

101

9

muscles and muscle tissue

Goals Overview of muscle tissue 1. Compare and contrast the basic types of muscle tissue. 2. Name four important functions of muscle tissue. Skeletal muscle 3. Describe the general structure of skeletal muscle. 4. Describe the microscopic structure and functional roles of the myofibrils, sarcoplasmic reticulum, and T-tubules of skeletal muscle fibers. 5. Describe the sliding filament model of muscle contractions. 6. Explain how muscle fibers are stimulated to contract by describing the events that take place at the neuromuscular junction. 7. Describe how an action potential is generated. 8. Follow excitation-contraction coupling events leading to cross-bridge activity. 9. Define motor unit and muscle contraction and describe the events that occur during the three phases of a muscle contraction. 10. Explain how smooth gradual contractions of skeletal muscle occur. 11. Distinguish between isometric and isotonic contractions.

12. Describe three ways in which ATP is regenerated during skeletal muscle contraction. 13. Define hypoxia and muscle fatigue. List the possible causes of muscle fatigue. 14. Describe the factors that affect the force, speed, and duration of skeletal muscle contraction. 15. Describe three types of skeletal muscle fibers and explain the relative value of each type. 16. Compare and contrast the effects of aerobic and resistance exercise on skeletal muscle and other body systems. Smooth Muscle 17. Compare the gross and microscopic anatomy of smooth muscle fibers with that of skeletal muscle fibers. 18. Compare and contrast the contractile mechanisms and means of activating skeletal and smooth muscle in the body. 19. Distinguish structurally and functionally between unitary and multiunit smooth muscle. Aspects of muscle development 20. Describe the embryonic development of muscle tissue and the age-related changes in skeletal muscle.

102 Copyright © 2010 Pearson Education, Inc.

Chapter 9

muscles and muscle tissue

Suggested Lesson Plan I. General Description of Muscle Tissue (pp. 276-277; Table 9.3) A. Types of Muscle Tissue (p. 276; Table 9.3) 1. Skeletal muscle is associated with the bony skeleton and consists of large cells that support the ligaments and be controlled voluntarily. 2. The heart muscle is unique to the heart and consists of small striated cells and is under involuntary control. 3. Smooth muscle is found in the walls of hollow organs and is made up of small, elongated cells that are not striated and are involuntarily controlled. B. Special Properties of Muscle Tissue (p. 276) 1. Excitability or irritability is the ability to receive and respond to a stimulus. 2. Contractility is the ability to contract forcefully when stimulated. 3. Extensibility is the ability to stretch. 4. Elasticity is the ability of cells to return to their original length once stretched. C. Muscle Functions (pp. 276-277; Table 9.3) 1. Muscles produce movement by acting on the bones of the skeleton, pumping blood, or propelling substances through lumen systems. 2. Muscles help maintain posture by adjusting the body's position in relation to gravity. 3. Muscles stabilize joints by placing tension around the joint. 4. Muscles generate heat through their cellular metabolic processes.

II. Skeletal muscle (pp. 277-305; Figs. 9.1-9.25; Tables 9.1-9.3) A. General anatomy of skeletal muscle (pp. 277-278; Fig. 9.2; Tables 9.1, 9.3) 1. Each muscle has a nerve and the blood supply, which enables neural control and ensures adequate nutrient supply and waste elimination. 2. Connective tissue sheaths are found at different structural levels in each muscle: the endomysium surrounds each muscle fiber, the perimysium surrounds groups of muscle fibers, and the epimysium surrounds entire muscles. 3. The attachments extend across the joints, causing movement from the mobile bone (the muscle insertion) to the less mobile bone (the muscle origin). 4. Muscle attachments can be direct or indirect. B. Microscopic anatomy of a skeletal muscle fiber (pp. 278-284; Figs. 9.2-9.6; Tables 9.1, 9.3) 1. Skeletal muscle fibers are long, multinucleated columnar cells located below the sarcolemma. 2. Myofibrils make up about 80% of the cell volume and contain the contractile elements of the muscle cell. 3. The Schlieren is due to a repeated series of dark A bands and light I bands. 4. Myofilaments form myofibrils and are composed of thick and thin filaments. 5. Ultrastructure and Molecular Composition of Myofilaments a. There are two types of myofilaments in muscle cells: thick filaments made up of bundles of myosin and thin filaments made up of actin filaments. B. Tropomyosin and troponin are regulatory proteins present in thin filaments.

Copyright © 2010 Pearson Education, Inc.

103

104

Text and Media Human Anatomy and Physiology Instructor's Guide 6. The sarcoplasmic reticulum is a smooth endoplasmic reticulum that surrounds each myofibril. 7. The T-tubules are internal folds of the sarcolemma that conduct electrical impulses from the cell surface to the terminal cisternae. C. The sliding filament model of muscle contraction states that during contraction, the thin filaments slide past the thick filaments. The overlap between the myofilaments increases and the sarcomere shortens (p. 284; Fig. 9.6). D. Physiology of a skeletal muscle fiber (pp. 284-289; Figs. 9.6-9.12; Table 9.3) 1. The neuromuscular junction is a connection between an axonal terminal and a muscle fiber, which is the pathway for electrical stimulation of the muscle. Cell 2. A nerve impulse causes the release of acetylcholine at the synaptic cleft, which binds to receptors on the motor endplate and initiates a series of electrical events in the sarcolemma. 3. Generation of an action potential across the sarcolemma occurs in response to acetylcholine binding to receptors on the motor endplate. It involves the influx of sodium ions, making the membrane potential slightly less negative. 4. Excitation-contraction coupling is the sequence of events by which an action potential in the sarcolemma results in myofilament slippage. 5. Ionic calcium during muscle contraction is maintained at almost undetectable levels in the cell by the regulatory action of intracellular proteins. 6. Muscle fiber contraction follows exposure of myosin binding sites and follows a series of events. E. Contraction of Skeletal Muscle (pp. 289-296; Figs. 9.13-9.18) 1. A motor unit consists of a motor neuron and all the muscle fibers that it innervates. It is lowest in muscles that exhibit fine control. 2. Muscle contraction is a muscle's response to a single action potential in its motor neuron. 3. There are three types of graded muscle responses: wave summation, multiple motor unit summation (recruitment), and staircase. 4. Muscle tone is the phenomenon that muscles contract slightly, even at rest, keeping them taut, healthy and responsive. 5. Isotonic contractions cause movement in the joint and shortening of the muscles. 6. Isometric contractions increase muscle tension, but neither lengthen nor shorten the muscles. F. Muscle Metabolism (pp. 296-300; Figs. 9.19-9.20) 1. Muscles contain very little stored ATP and used ATP is rapidly replenished by creatine phosphate phosphorylation, glycolysis and anaerobic respiration and aerobic exercise. 2. Muscles function aerobically as long as there is sufficient oxygen, but when the demands of exercise exceed the capacity of muscle metabolism to meet ATP needs, metabolism switches to anaerobic glycolysis. 3. Muscle fatigue is a problem in the excitation-contraction coupling or within the muscle cells themselves. 4. Oxygen deficit is the extra oxygen needed to support oxygen stores, glycogen stores, ATP and creatine phosphate stores, and the conversion of lactic acid to pyruvic acid glucose after intense exercise replenish muscle activity.

Copyright © 2010 Pearson Education, Inc.

Chapter 9

muscles and muscle tissue

5. Heat build-up during muscle activity is significant. It requires the release of excess heat from the skin through homeostatic mechanisms such as sweating and radiation. G. Force of Muscle Contraction (pp. 300-302; Figs. 9.21-9.22) 1. As the number of muscle fibers stimulated increases, the force of contraction increases. 2. Large muscle fibers produce more force than smaller muscle fibers. 3. As the rate of stimulation increases, the contractions increase, eventually leading to tetanus and generating more force. 4. An ideal length-to-tension relationship is when the muscle is slightly stretched and there is a slight overlap between the myofibrils. H. Rate and Duration of Muscle Contraction (pp. 302-303; Figs. 9.23-9.25; Tables 9.2-9.3) 1. There are three types of muscle fibers: slow oxidative fibers, fast oxidative fibers and fast glycolytic fibers. 2. Muscle fiber type is a genetically determined trait, with different percentages of each fiber type in each muscle being determined by the specific function of a given muscle. 3. With increasing load, the speed of the contraction decreases and the duration of the contraction decreases. 4. Recruitment of additional motor units increases the speed and duration of the contraction. I. Effect of Exercise on Muscles (pp. 304-305) 1. Aerobic or resistance exercise promotes increased capillary penetration, an increase in the number of mitochondria, and an increase in myoglobin synthesis, resulting in more efficient metabolism, but without hypertrophy. 2. Resistance exercises such as weight lifting or isometric exercises promote increased numbers of mitochondria, myofilaments and myofibrils, and glycogen storage, resulting in hypertrophied cells.

3. Smooth muscle (pp. 305-311; Figs. 9.26-9.29; Table 9.3) A. Microscopic structure of smooth muscle fibers (pp. 305-307; Figs. 9.26-9.28; Table 9.3) 1. Smooth muscle cells are small , spindle-shaped cells with a central nucleus that lack the thick connective tissue envelope of skeletal muscle. 2. Smooth muscle cells are usually arranged in layers of opposing fibers, forming a longitudinal layer and a circular layer. 3. The contraction of the opposing layers of muscle results in a rhythmic form of contraction called peristalsis, which moves substances through the organs. 4. Smooth muscle has no neuromuscular connections, but varicose veins, numerous bulbous protrusions that release neurotransmitters into a wide synaptic cleft. 5. Smooth muscle cells have a less developed sarcoplasmic reticulum that sequesters large amounts of calcium in the extracellular fluid within the cell membrane caveolae. 6. Smooth muscle has no streaks, no sarcomeres, a lower ratio of thick to thin filaments compared to skeletal muscle, and contains tropomyosin but no troponin.

Copyright © 2010 Pearson Education, Inc.

105

106

7. Smooth muscle fibers contain longitudinal bundles of non-contractile intermediate filaments anchored by dense bodies to the sarcolemma and surrounding tissues. B. Smooth muscle contraction (pp. 307-311; Fig. 9.29; Table 9.3) 1. Mechanism and characteristics of contraction a. Smooth muscle fibers exhibit slow, synchronous contractions due to electrical coupling at gap junctions. B. As in skeletal muscle, actin and myosin interact through the sliding filament mechanism. The ultimate trigger for the contraction is an increase in intracellular calcium levels, and ATP drives the process. C. During excitation-contraction coupling, calcium ions enter the cell from the extracellular space, bind calmodulin and activate the myosin light chain kinase, thereby activating the cross-bridge cycle. i.e. Smooth muscle contracts more slowly and uses less ATP than skeletal muscle. 2. Allocation regulations a. Autonomous nerve endings release acetylcholine or norepinephrine, which can cause certain groups of smooth muscle cells to be excited and others to be inhibited. B. Hormones and local factors such as lack of oxygen, histamine, excess carbon dioxide or low pH act as contraction signals. 3. Peculiarities of smooth muscle contraction a. Smooth muscle initially contracts when stretched, but the contraction is brief and then the cells relax to accommodate the stretch. B. Smooth muscle stretches more and creates more tension when stretched than skeletal muscle. C. Hyperplasia, an increase in the number of cells due to division, is possible along with hypertrophy, an enlargement of individual cells. C. Types of smooth muscle (p. 311) 1. One-piece smooth muscles, called visceral muscles, are the most common type of smooth muscle. It contracts rhythmically as a unit, electrically couples through gap junctions, and exhibits spontaneous action potentials. 2. Compound smooth muscle is found in the large airways leading to the lungs, the large arteries, the arector pili muscles in the hair follicles, and the iris of the eye. It consists of structurally independent cells, has motor units and is capable of gradual contractions.

4. Aspects of muscle development (pp. 311-312; Fig. 9.30) A. Most muscle tissue develops from specialized mesodermal cells called myoblasts (p. 311). B. Skeletal muscle fibers are formed by the fusion of multiple myoblasts and actively contract in the seventh week of fetal development (p. 311). C. Cardiac and smooth muscle myoblasts do not fuse but form gap junctions at a very early stage (p. 312). D. Infant muscle development is primarily reflex at birth and progresses from head to toe and proximal to distal (p. 312). E. Women have relatively less muscle mass than men due to the action of the male sex hormone testosterone, which is responsible for the difference in strength between the sexes (p. 312). Copyright © 2010 Pearson Education, Inc.

Chapter 9 f.

muscles and muscle tissue

Muscular dystrophy is one of the few muscle diseases and is characterized by atrophy and degeneration of muscle tissue. Muscle gain is due to the deposition of fat and connective tissue (p. 312).

Cross-references For more information on the topics covered in Chapter 9, refer to the chapters listed below. 1. Chapter 2: ATP; Ions 2. Chapter 3: General cellular structural components; membrane transport; microfilaments; gap junctions; membrane potentials 3. Chapter 4: connective tissue; Muscle tissue 4. Chapter 6: Structure of bone tissue 5. Chapter 8: Joint stability as a function of skeletal muscle contraction 6. Chapter 10: Skeletal muscles of the body; Muscle-Bone Interaction 7. Chapter 11: General Structure and Function of Synapses and Neurotransmitters 8. Chapter 13: Sensory Receptors in Skeletal Muscle; Motor Neurons of the Peripheral Nervous System and Neuromuscular Connections 9. Chapter 18: Function of Heart Tissue; example of the sliding thread mechanism of muscle contraction 10. Chapter 19: Use of smooth muscle 11. Chapter 23: Use of smooth muscle; Smooth muscle unit function related to peristalsis 12. Chapter 24: Metabolic pathways of energy production (glycolysis, Krebs cycle and electron transport); Trembling as a Heat Generating Mechanism 13. Chapter 27: Use of Smooth Muscle

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 14: Microscopic anatomy and organization of skeletal muscle Exercise 16a: PhysioEx™ 8.0 Skeletal muscle physiology Exercise 16b: Skeletal muscle physiology: computer simulation 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 14: Microscopic Anatomy and Organization of Skeletal Muscle Exercise 16a: PhysioEx™ Skeletal Muscle PhysioEx™ 8.0 Exercise 16b: Skeletal Muscle Physiology: Computer Simulation

Teaching Tips 1. The terminology used to describe the functional properties of muscles is confusing for many students. Point out that "expand" is a root of the word extensibility and that it's easy to associate stretch with expansion. Elasticity (the ability to move back) is the opposite of extensibility. 2. Because the prefixes endo-, epi-, and peri- are commonly used in anatomical terminology, emphasize their importance and indicate that students will see them again. 3. A good way to reconstruct the general structure of muscle tissue from the myofilaments to the entire muscle is to use a cross-sectional diagram. students are

Copyright © 2010 Pearson Education, Inc.

107

108

Text and media guide to human anatomy and physiology

4.

5.

6. 7.

8.

9.

10. 11.

it is often confused by the similarity in the names of the structures, e.g. myofilaments vs. myofibrils vs. muscle fibers. Use analogies to help students remember: filaments are like lightbulbs, very thin, that form the basic structure to evoke an action (light); Instead, fibers are larger structures and, like nerve fibers, are cells; the term fibril lies between the two. When describing the filament sliding mechanism, be sure to use multiple drawings (or diagrams) of the relationships between the thick and thin filaments during contraction. Students are easily confused by the series of static diagrams presented. Be sure to state the dynamic nature of the contraction. Students often struggle with "all or nothing" applied to individual muscle fibers. Point out clearly the difference between muscle cells (and motor units) and the whole muscle. Use the analogy of a light switch that controls all lightbulbs connected to it: on or off, without an intermediary. Emphasize that a gradual muscle contraction is achieved by increasing the frequency of motor unit stimulation or the number of motor units activated. To introduce isometric and isotonic contractions, ask the class whether muscle contractions always lead to movement. Whatever the answer, illustrate your point by trying to lift a stationary object in the classroom. Point out that although the force increases, the object does not rise; therefore the muscle must remain the same length. Ask what system of linear measurement is used in science. Someone will answer "metric", at which point the definition of the iso prefix must be given. Using real-life analogies will help students remember these very similar terms. To illustrate the length-tension relationships, ask the class to discuss the amount of force generated when myosin and actin do not overlap so that the myosin heads do not intersect the actin. On the other hand, are you asking what would happen if myosin and actin completely overlapped? When explaining the differences between slow and fast (oxidative) fibers, it is helpful to provide examples of different types of athletes and the types of muscle fibers that are prevalent as a result of specific exercises. Students will easily remember these examples (and the principles) if they can relate them to real-life experiences. Explain that all muscle types contain actin and myosin myofilaments, but that arrangement accounts (in part) for structural and functional differences. Be sure to inform students that the terms skeleton and skeletal muscle are interchangeable and that although cardiac muscle is striated, the term striated should not be used to name cardiac muscle.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Demonstrate muscle contraction using a simple myograph or kymograph and a frog's gastrocnemius muscle. A movie loop can be used to display these events. It is important for students to be able to visualize these events. 3. Have students demonstrate examples of isometric and isotonic contractions and explain how individual muscle cells and motor units behave to elicit muscle contraction. 4. Set up a microscope with a slide for the motor unit to view in class. 5. Use models comparing the three types of muscle tissue to point out the unique structural features of each type. 6. Use an articulated skeleton to mark different origins and insertions; Then ask students to specify the resulting movement. 7. Pull apart a piece of cooked chicken breast to demonstrate the individual fascicles. Copyright © 2010 Pearson Education, Inc.

Chapter 9

muscles and muscle tissue

8. Obtain a 3D model of a sarcomere to visualize tubules and myofibrils. 9. Obtain or construct a 3D model of a sarcomere that illustrates the sliding thread mechanism of muscle contraction. 10. Emphasize the importance of extracellular calcium ions in smooth muscle contraction and distinguish them from skeletal muscle, which is more dependent on stored intracellular calcium ions. 11. Use a microprojector and microslides of skeletal, smooth, and cardiac muscles to illustrate their microscopic similarities and differences.

Critical Thinking/Points for Discussion 1. You are caught in a sudden snowstorm and have no shelter or warm clothing. Why is it important for you to keep moving and moving instead of sitting motionless on the ground waiting for rescue? 2. Muscles that are immobilized for long periods of time, e.g. B. in a plaster cast, are often smaller. There? What is needed to revitalize them? 3. Why do you think activities like swimming and brisk walking are so beneficial? Are there negative attributes of activities like racquetball and running? 4. How can weight lifters have such big muscles while long distance runners have lean muscles? 5. What would be the effect on the body if the peristaltic movements of the bowel were interrupted by infection or injury? 6. Why do athletes "warm up" before a competitive event? Would you expect the warm up to make the contraction more or less efficient? There? 7. Visit a local gym frequented by bodybuilders. Learn about the methods of building muscle mass and an explanation of how these methods achieve this goal. 8. If the number of myosin heads were doubled, what would be the impact on force production? ATP consumption? 9. What is a muscle spasm? How do you think it can be caused? 10. Are spasms and cramps related? Compare and contrast the different possible mechanisms of each. 11. Draw diagrams of different arrangements of fascicles and describe what type of movement is characteristic of each (eg close range, powerful, etc.). , the origin and insertion of the deltoid is a logical example of the perfect use of a convergent pattern).

Library Research Topics 1. Why have muscle cells “lost” their ability to regenerate? What current research is being done in this area? 2. Study the long-term effect of anabolic steroid use on muscle tissue. 3. Why do you think the Olympic Committees are so adamant about the use of "performance enhancing" drugs like anabolic steroids? 4. Follow the embryonic development of skeletal muscle and observe how it is in constant contact with nerve cells. 5. Examine current theories on the etiology of muscular dystrophy. 6. What is the current status of the sliding filament model of muscle contraction? Do we know everything there is to know? Copyright © 2010 Pearson Education, Inc.

109

110

Text and Media Human Anatomy and Physiology Teacher Guide 7. Investigate how biofeedback can reduce stress-induced muscle tension. 8. Describe various disorders of muscle metabolism (usually due to a deficiency in one or a group of enzymes). 9. Alcohol can induce a form of toxic myopathy. Describe the effect of alcohol on muscle tissue. 10. Define the term myositis. Which pathogens can lead to this form of muscle disease? 11. Are the tumors (benign or malignant) related to muscle tissue? Would the cancer originate in the muscle cells themselves or in the connective tissue coverings? Discover the possibilities.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all of the chapter-specific online media resources for Chapter 9 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 9.1 Overview of muscle tissue (pp. 276-277) Flix A&P animation: The neuromuscular junction Flix A&P animation: Excitation-contraction coupling Flix A&P animation: The bridging cycle Flix A&P animation: The membrane potential at rest Animation Flix A&P : Generation of an Action Potential Animation A&P Flix: Propagation of an Action Potential MP3 Tutor Session: Theory of Sliding Filament Contraction MP3 Tutor Session: Events at the Neuromuscular Junction Interactive Physiology® 10-System Suite: Muscular System: Anatomy Review: Skeletal Muscle Tissue Section 9.2 Skeletal Muscle (p 277-305) Physiology® 10-System Interactive Set: Muscular System: The Neuromuscular Connection Physiology® 10-System Interactive Set: Muscular System: Theory Sliding Filament Set of 10 Physiology® Interactive Systems: Muscular System: Muscle Metabolism Interactive Physiology® 10-System Suite: Muscular System: Motor Unit Contraction s Interactive Physiology® 10-System Suite: Muscular System: Whole Muscle Contraction Artist Labeling: Skeletal Muscle Connective Tissue Covers: Epimysium, Perimysium and Endomysium (Fig. 9.1, p. 278) Artist's caption: Microscopic anatomy of a skeletal muscle fiber (Fig. 9.2a-d, p. 280)

Copyright © 2010 Pearson Education, Inc.

Chapter 9

muscles and muscle tissue

PhysioEx™ 8.0: Skeletal Muscle Physiology Section 9.3 Smooth Muscle (pp. 305-311) Memory Game: Muscle Tissues Memory Game: Muscle Tissue Architecture Section 9.4 Aspects of Muscle Development (pp. 311-312) Case Study: Neuromuscular Dysfunction Chapter Summary Crossword Puzzle 9.1 Crossword 9.2 Crossword 9.3 Web Links Chapter Tests Art Labeling Test Matching Test Multiple Choice Test Chapter Practice Test Practice Test Learning Tools Histology Atlas myeBook Flashcards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1. Human Muscle Videotape (BC; 23 min., 1999). Rose Leigh Vines, California State University. It offers a clear 23-minute anatomical tour of the muscles of the human body; an inexpensive alternative to cadaver dissection. 2. Muscles and Joints: Muscle Strength (FHS; 28 min, 1984). Illustrate the microscopic view of muscles and compare the three muscle types. 3. Muscles (FHS; 20 min). From the series The New Living Body. Introduces the nature of muscle tissue in the body and explains the complex movements involved in training. The muscle is examined from general structure to detailed microstructure. 4. Muscular System: The Athlete Within (FHS; 24 min, 1998). From the The Human Body: Systems at Work series, this program explores the many roles muscles play in our daily lives. 5. The skeletal and muscular system (NIMCO; 24 min). Demonstrates how the skeletal and muscular systems work together to provide the structure and shape of the body.

Copyright © 2010 Pearson Education, Inc.

111

112

Text and media guide to human anatomy and physiology

Software 1. Set of 10 Interactive Physiology® systems: Muscular System (BC; Win/Mac, 2008). It offers a clear and interactive exploration of some of the most difficult concepts in muscle physiology. 2. Practice Anatomy Lab™ 2.0: Human Cadaver, Histology (see full list on page 9 of this manual).

Material to improve the lesson Thumbnails of all illustrations in Chapter 9 can be found in Appendix B.

Index Instructor Slide/Resource DVD Image Image Image Image

9,1 9,2 9,3 9,4

Figure 9.5 Figure Figure Figure Figure

9,6 9,7 9,8 9,9

figure figure figure figure

9,10 9,11 9,12 9,13

Figure 9.14 Figure 9.15 Figure 9.16 Figure Figure Figure Figure

9,17 9,18 9,19 9,20

Figure Figure Figure Figure Figure Figure Figure

9,21 9,22 9,23 9,24 9,25 9,26 9,27 9,28

connective tissue coverings of skeletal muscle. Microscopic anatomy of a skeletal muscle fiber. Composition of thick and thin filaments. Transmission electron micrograph of a portion of a sarcomere clearly showing the bridged myosin heads that generate the force of contraction. Relationship of the sarcoplasmic reticulum and T-tubules to the myofibrils of skeletal muscle. Contraction glide line model. The phases that lead to the contraction of muscle fibers. Events at the neuromuscular junction. Summary of events in generation and propagation of an action potential in a skeletal muscle fiber. Action potential scan showing changes in the Na+ and K+ ion channels. alternation of excitation-contraction. Cross the bike bridge. A motor unit consists of a motor neuron and all the muscle fibers that it innervates. muscle contraction. The muscular response to changes in stimulation rate. Relationship between stimulus intensity (top graphic) and muscle tension (bottom graphic). The principle of the size of recruitment. Isotonic (concentric) and isometric contractions. Ways to regenerate ATP during muscle activity. Comparison of energy sources used during short-term exercise and long-term exercise. Factors affecting the force of skeletal muscle contraction. Length-tension relationships of sarcomeres in skeletal muscle. Factors affecting the rate and duration of skeletal muscle contraction. Cross section of the three types of fibers in skeletal muscle. Influence of the load on the duration and speed of the contraction. Arrangement of smooth muscle in the walls of hollow organs. smooth muscle innervation. The intermediate filaments and dense bodies of smooth muscle fibers harness the attractive force created by the myosin cross-bridges.

Copyright © 2010 Pearson Education, Inc.

Chapter 9 Figure 9.29 Figure 9.30 Table 9.1 Table 9.2 Table 9.3 A Closer Look Making Connections

muscles and muscle tissue

Sequence of events in smooth muscle excitation-contraction coupling. Formation of a multinucleated skeletal muscle fiber by fusion of myoblasts. Skeletal Muscle Structure and Organizational Levels Structural and functional properties of the three types of skeletal muscle fibers Comparison of skeletal, cardiac and smooth muscle athletes Do they look good and perform better on anabolic steroids? Homeostatic interrelationships between muscles and other body systems

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 15. The functions are: Excitability: the ability to receive and respond to a stimulus; contractility - the ability to shorten; Extensibility - the ability to stretch; and elasticity - the ability to regain normal length after contraction or stretching. (p. 276) 16. a. In the direct approach, the epimysium of the muscle is fused to the periosteum of a bone, and in the indirect approach, the fibrous sheaths of the muscle extend beyond the muscle like a tendon; the tendon is anchored to the periosteum of a bone. (pp. 277 and 278) b. A tendon is a rope-like mass of fibrous tissue; an aponeurosis is a flat, broad blade. (p. 278) 17. a. A sarcomere is the region of a myofibril between two consecutive Z-lines and is the smallest contractile unit in a muscle cell. The myofilaments are located inside the sarcomere. (p. 281; Figure 9.2) b. The theory is that the thin filaments slide towards the center of the sarcomere by the ratcheting action of the myosin heads. The process is powered by ATP. (p. 284; Fig. 9.6) 18. AChE destroys ACh after it is released. This prevents a continuous contraction of the muscle fiber without additional stimulation. (p. 285) 19. A light but gentle contraction involves rapid stimulation of a few motor units and affects only a few muscle fibers in the muscle, while a strong contraction would affect many (or all) of the technically stimulated motor units. (p. 295) 20. Excitement-contraction coupling is the sequence of events by which an action potential traveling along the sarcolemma causes a muscle fiber to contract. (p. 288; Fig. 9.11) 21. A motor unit is the motor neuron and all the muscle fibers that it controls. (p. 289; Fig. 9.13) 22. Table 9.2, p. 302, illustrates the structural and functional properties of the three types of skeletal muscle fibers. 23. Wrong. Most muscles in the body contain a mix of fiber types that allow them to exhibit a range of contraction speeds and resistance to fatigue. However, certain types of muscle fibers may be predominant in certain muscles, for example, white fibers are predominant in the eye muscles. (p. 303) Copyright © 2010 Pearson Education, Inc.

113

114

Text and media Teacher's manual of human anatomy and physiology 24. Muscle fatigue is the state of physiological inability to contract. It is produced by ATP deficiency, lactic acid accumulation and ion imbalance. (p. 300) 25. Oxygen deficit is defined as the additional amount of oxygen that the body needs to take in to allow for regeneration processes and represents the difference between the amount of oxygen required for fully aerobic respiration during muscular activity and that actually amount consumed. (p. 300) 26. Smooth muscle is found within the walls of hollow organs and around blood vessels. The tissue is under involuntary control. These properties are essential because hollow vessels and organs must react slowly, fill and expand slowly, and avoid expulsive contractions. (pp. 308-311)

Critical Thinking Questions and Clinical Application 1. Regular resistance exercise leads to increased muscle strength, which leads to hypertrophy, or enlargement, of muscle cells. The number of myofilaments increases in these muscles. (p. 304) 2. The reason for the narrowness is rigor mortis. Myosin cross-bridges are "attached" to actin due to a lack of ATP needed for their release. No, maximum stiffness occurs within 12 hours and then gradually disappears over the next 48-60 hours as biological molecules begin to break down. (p. 289) 3. Chemical A. By blocking the binding of ACh to the motor endplate, neural stimulation of the cell is blocked and the muscle cell cannot depolarize. Chemical B would actually increase muscle cell contraction by increasing the availability of calcium ions, which bind troponin and contribute to actin-myosin bridging. (pp. 285, 288-289) 4. Calcium actually binds to troponin, which changes shape and moves tropomyosin to expose the myosin head binding sites. (p. 281)

Suggested Reading Barinaga, M. "The Titanic Protein Provides Structure and Balance to Muscles." Science 270 (October 1995): 236. Barry, Patrick. "Regulation of muscle breakdown". Science News 172 (October 2007): 244-245. Bers, D. and M. Fill. "Coordinated Feet and the Dance of the Ryanodine Receptors". Science 281 (August 1998): 790–791. Block, SM "One Small Step for Myosin." Nature 378 (November 1995): 132-133. Campbell, K. and R. Crosbie. "Gene Therapy." Science and Medicine 4 (November 1996): 6–7. DeRosier, D. "The Shape Change of Actin." Nature 347 (September 1990): 21. Fackelmann KA "The Nine-Month Arthritis Cure". Science News 144 (October 1993): 266. Gautam, M., et al. "Postsynaptic specialization failed to develop at the neuromuscular junctions of rapsyn-deficient mice". Nature 377 (September 1995): 232-236. Goldman, Y. and H. Higuchi. "Gliding distance between actin and myosin filaments per hydrolyzed ATP molecule in skin muscle fibers". Nature 352 (July 1991): 352. Grady, D. "One Foot Forward." Discover 11 (September 1990): 86–93. Hartwig, JS, et al. "Effect of ATP on actin filament stiffness". Nature 347 (September 1990): 95. Huxley, A. "Crossbridge Tilting Confirmed". Nature 375 (June 1995): 631-632.

Copyright © 2010 Pearson Education, Inc.

Chapter 9

muscles and muscle tissue

Jo, AS, et al. "Neurgulins are enriched in nerve-muscle synapses and activate expression of the ACh receptor gene." Nature 373 (January 1995): 158-164. Johnson, KA and F. Quiocho. "Twisted Worms Trap S100". Nature 380 (1996 April): 585. Klein, M.G., et al. "Two mechanisms of quantified calcium release in skeletal muscle". Nature 379 (February 1996): 455-458. Labeit, S. and B. Kolmerer. "Titins: giant proteins responsible for muscle ultrastructure and elasticity". Science 270 (October 1995): 293-296. Lin, Weichun and others. "Different roles of nerves and muscles in the postsynaptic differentiation of the neuromuscular junction". Nature 410 (6832) (April 2001): 1057-1064. Linari, M., V. Lombardi, and G. Piazzesi. "Rapid regeneration of the actin-myosin power stroke in muscle contraction". Nature 355 (February 1992): 638. Nakai, J., et al. "Enhanced channel activity of the dihydropyridine receptor in the presence of the ryanodine receptor". Nature 380 (March 1996): 72-75. Pennisi, E. "Three-dimensional atomic view of the muscle molecule." Science News 144 (July 1993): 4. Piazzesi, G., et al. "Mechanism of Force Generation by Myosin Heads in Skeletal Muscle". Nature 415 (6877) (February 2002): 659-662. Sheffield-Moore, M., D. Paddon-Jones and R.J. Urban. "Amino acid supplementation and skeletal muscle metabolism in aging populations". Hormone research 66, supplement. no 1 (2006): 93-97. Service, RF "Exercise muscle with just one amino acid." Science 271 (January 1996): 31. Somiyo, A.P., and A.V. somiyo "Signal transduction and regulation in smooth muscle". Nature 372 (November 1994): 231-236. Spudich, James A. "The Myosin Oscillating Crossbridge Model." Nature Reviews: Molecular Cell Biology 2 (5) (May 2001): 387-392. Suominen, Harry. "Physical activity and health: musculoskeletal problems". Advances in Physiotherapy 9, No. 2 (2007): 65–75. Travis, J. "Antibiotics for muscular dystrophy?" Science News 156 (August 1999): 84.

Copyright © 2010 Pearson Education, Inc.

115

10

the muscular system

Objectives Skeletal Muscle Interactions in the Body 1. Describe the function of the main movers, antagonists, synergists and fixators. Naming Skeletal Muscles 2. List the criteria used to name muscles. Provide an example to illustrate the use of each criterion. Muscle Mechanics: Importance of Fascicular Arrangement and Leverage 3. List common patterns of muscle fascicle arrangement and relate them to force production.

4. Define leverage and explain how a lever that works with a mechanical advantage differs from a lever that works with a mechanical disadvantage. 5. Name the three types of lever systems and indicate the force, pivot point and load arrangement for each. Also consider the benefits of each lever system. Major Skeletal Muscles of the Body 6. Name and identify the muscles described in Tables 10.1 through 10.17. State the origin, insertion, and effect of each.

Suggested Lesson Plan I. Skeletal Muscle Interactions in the Body (p. 321) A. Muscles simply pull; they cannot push (p. 321). B. The muscle providing the greatest force for the specific movement is termed the primary mover or agonist (p. 321). C. Muscles that oppose or reverse a particular movement are called antagonists (p. 321). D. Synergists support driving forces by adding additional power to the movement itself or by reducing unwanted or unnecessary movement (p. 321).

II. Naming Skeletal Muscles (pp. 321-322) A. Some muscle names indicate the bone or body region to which the muscle is attached (p. 321). B. Some muscles are named for their shape (p. 321). C. Terms such as maximus, minimus, longus, and brevis are often used in muscle names to indicate the relative size of the muscle (p. 321). D. The names of some muscles indicate the direction in which their fibers travel relative to an imaginary line in the body, such as B. the midline (p. 321).

116 Copyright © 2010 Pearson Education, Inc.

Chapter 10

the muscular system

E. The number of origins of a muscle can be indicated by the word biceps, triceps, or quadriceps in its name (p. 321). F. Some muscles are named for their place of origin and insertion (pp. 321-322). G. A muscle may be named for its action by using a word such as flexor or extensor in its name (p. 322).

3. Muscle Mechanics: Importance of Fascicle Arrangement and Leverage (pp. 322-324; Figs. 10.1-10.3) A. In skeletal muscle, the common arrangement of fascicles varies, resulting in muscles with different shapes and functional capabilities (pp. 322 to 323 ). ;Figure 10.1). 1. The fascicle pattern is circular when the fascicles are arranged in concentric rings. 2. A convergent muscle has a broad origin and its fascicles converge at a single tendon insertion. 3. When arranged parallel, the long axis of the fascicles is parallel to the long axis of the muscle. 4. A fusiform parallel arrangement of fascicles is sometimes classified as a fusiform muscle. 5. In a feathered pattern, the fascicles are short and obliquely attached to a central tendon that runs the length of the muscle. B. The function of most skeletal muscles involves the use of levers and lever systems, associations between muscular and skeletal systems (pp. 323-324; Figs. 10.2, 10.3). 1. A lever is a rigid rod that moves about a fixed point or pivot when a force is applied to it. 2. The force or tension applied is used to move a resistor or load. 3. In your body, joints act as pivots, bones act as levers, and muscle contractions act as effort. 4. There are three types of levers: first class, second class and third class.

4. Large skeletal muscles of the body (pp. 324-382; Figs. 10.4-10.25; Boxes 10.1-10.17) A. Head muscles, part I: facial expression (pp. 329-331; Fig. 10.6; Box 10.1 ) 1. To the Muscles of the scalp include the epicranium, which consists of the frontal abdomen and the occipital abdomen. 2. The facial muscles include corrugator supercilii, orbicularis oculi, zygomaticus, risorius, levator labii superioris, depressor labii inferioris, depressor anguli oris, orbicularis oris, mentalis, buccinator, and platysma. B. Muscles of the Head, Part II: Chewing and Tongue Movement (pp. 332-333; Fig. 10.7; Table 10.2) 1. The muscles of mastication include the masseter, temporalis, medial pterygoid, lateral pterygoid, and buccinator. . 2. The muscles that promote tongue movements are the genioglossus, hyoglossus, and styloglossus.

Copyright © 2010 Pearson Education, Inc.

117

118

Text and media Teacher's manual of human anatomy and physiology C. Muscles of the anterior neck and pharynx: Swallowing (pp. 334-335; Fig. 10.8; Table 10.3) geniohyoid. 2. The infrahyoid muscles include the sternohyoid, sternothyroid, omohyoid, thyrohyoid, and pharyngeal constrictor muscles (upper, middle, and inferior). D. Neck and Spine Muscles: Head Movements and Trunk Extension (pp. 336-339; Fig. 10.9; Table 10.4) 1. The anterolateral neck muscles include the sternocleidomastoid and scalenee (anterior, middle, and posterior). 2. The intrinsic muscles of the back include splenius capitis, splenius neck, erector spinae (sacrospinatus), iliocostalis, longissimus, spinalis, semispinalis, and quadratus lumborum. E. Pectoral Muscles: Breathing (pp. 340-341; Fig. 10.10; Table 10.5) 1. The pectoral muscles include the external intermediate ribs, the internal intermediate ribs, and the diaphragm. F. Muscles of the Abdominal Wall: Movements of the Trunk and Compression of the Abdominal Viscera (pp. 342-343; Fig. 10.11; Table 10.6) 1. The muscles of the anterolateral abdominal wall include the rectus abdominis, external oblique, internal oblique, and the transversal. Abdomen G. Pelvic Floor and Perineum Muscles: Supporting the Abdominal Pelvic Organs (pp. 344-345; Fig. 10.12; Table 10.7) 1. The pelvic floor muscles include the levator ani and the coccyx. 2. The muscles of the urogenital diaphragm include the deep perineal transverse muscle and the external urethral sphincter. 3. The muscles of the superficial space include the ischiocavernosus, bulbospongiosus, and superficial transverse perineum. H. Superficial musculature of the anterior and posterior rib cage: movements of the scapula (pp. 346-349; Fig. 10.13; Table 10.8) 1. The muscles of the anterior rib cage include the pectoralis minor, serratus anterior and subclavius. 2. The posterior chest muscles include the trapezius, levator scapulae, and rhomboids (major and minor). I. Muscles Above the Shoulder Joint: Movements of the Upper Arm (pp. 350-352; Fig. 10.14; Table 10.9) 1. The muscles that move the arm are pectoralis major, dorsiflexus maximus, deltoid, and supraspinatus and the infraspinatus, the teres minor, the teres major, and the coracobrachialis. J. Muscles Above the Elbow Joint: Flexion and Extension of the Forearm (p. 353; Fig. 10.14; Table 10.10) 1. The posterior muscles include the triceps brachii and the anconeus. 2. The anterior muscles include the biceps brachii, brachialis, and brachioradialis. K. Forearm Muscles: Wrist, Hand, and Finger Movements (pp. 354-357; Figs. 10.15, 10.16; Table 10.11) 1. The superficial anterior muscles include the pronator teres, flexor carpi radialis, palmaris longus, and flexor ulnar. Carpus and flexor digitorum superficialis. 2. The deep anterior muscles include the flexor pollicis longus, flexor digitorum profundus, and pronator quadratus.

Copyright © 2010 Pearson Education, Inc.

Chapter 10

the muscular system

3. The posterior superficial muscles include the brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, and extensor carpi ulnaris. 4. The deep posterior muscles include the indices supinator, abductor pollicis longus, extensor pollicis brevis and longus, and extensor pollicis. L. Summary of the actions of the muscles acting on the arm, forehead and hand (pp. 358-359; Fig. 10.17; Table 10.12) M. Intrinsic muscles of the hand: fine finger movements (pp. 360-362, Fig. 10.18); Table 10.13) 1. The thenar muscles of the thenar include abductor pollicis brevis, flexor pollicis brevis, opponens pollicis, and adductor pollicis. 2. The hypothenar muscles of the little fingertip include the abductor digiti minimi, the flexor digiti minimi brevis, and the oponens digiti minimi. 3. The medial palmar muscles include the lumbricals, the palmar interosseuses, and the dorsal interosseuses. N. Muscles crossing the hip and knee joints: movements of the thighs and legs (pp. 363 and 369; Figs. 10.19 and 10.20; Table 10.14) 1. The anteromedial muscles include the iliopsoas, which consists of the iliacus and psoas composed main. , and the sartorius. 2. The muscles of the medial compartment of the thigh include the adductor group, which consists of the large adductor, long adductor, and short adductor, the pectineus, and the gracilis. 3. The muscles of the anterior thigh compartment include the quadriceps femoris group, which consists of the rectus femoris, vastus lateralis, vastus medialis and vastus intermedius, and the tensor fascia latae. 4. The posterior muscles are the glutes, which include the gluteus maximus, gluteus medius, and gluteus minimus. 5. Lateral rotators include the piriformis, external obturator, internal obturator, gemini, and quadratus femoris. 6. The muscles of the posterior department of the thigh include the hamstrings, which consist of the biceps femoris, semitendinosus, and semimembranosus. O. Leg muscles: movements of the ankle and toes (pp. 370-375; Figs. 10.21-10.23; Table 10.15) and the extensor hallucis longus. 2. The muscles of the lateral compartment include the peroneus longus (peroneus) and peroneus brevis (peroneus). 3. The superficial muscles of the posterior compartment include the triceps surae, composed of the gastrocnemius and soleus, and the plantaris. 4. The deep muscles of the posterior compartment include the popliteus, flexor digitorum longus, flexor hallucis longus, and posterior tibialis. P. Intrinsic Muscles of the Foot: Toe Movement and Arch Support (pp. 376-379; Fig. 10.24; Table 10.16) 1. The muscle on the dorsum of the foot is the extensor digitorum brevis. 2. The muscles of the sole of the foot in the first layer are the flexor digitorum brevis, the abductor hallucis, and the abductor digiti minimi. 3. The muscles of the sole of the foot in the second layer are the accessory flexors (quadratus plantaris) and the lumbricals.

Copyright © 2010 Pearson Education, Inc.

119

120

Text and media Teacher's manual of human anatomy and physiology 4. The muscles of the sole of the foot in the third layer include the flexor hallucis brevis, the adductor hallucis brevis, and the flexor digiti minimi brevis. 5. The muscles of the plantar in the fourth layer include the plantar and dorsal interosseous muscles. Q. Summary of the actions of the muscles acting on the thigh, leg and foot (pp. 380-381; Fig. 10.24; Table 10.17)

Cross-references For more information on the topics covered in Chapter 10, see the chapters listed below. 1. Chapter 7: Skull Bones; facial bones; spinal bones; the bony thorax; breast bones; the top end; pelvic girdle; Lower Limb 2. Chapter 8: Synovial Joints 3. Chapter 9: Skeletal Muscle Tissue 4. Chapter 22: Abdominal Muscles Involved in Breathing 5. Chapter 23: Chewing and Tongue Movement Muscles 6. Chapter 25: Muscles Involved in Controlling Urination 7. Chapter 27: Male and female perineum in relation to reproductive anatomy; pelvic floor muscles

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 15: Gross Anatomy of the Muscular System 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 15: Gross Anatomy of Muscles

Teaching Tips 1. It is easy for students to treat the muscular system (or any other system) as a unit without relating it to the rest of the body. Emphasize that students must match all specific muscles (and their associated synergists, antagonists, etc.). 2. Make sure students understand that movement is achieved through muscle contraction and contraction, never muscle contraction. 3. Students often do not easily understand the idea of ​​a tradeoff between strength and range of motion when discussing the relationship between origin and exact insertion site (e.g., biceps brachii at radial tubercle). Ask the class what would happen to the strength and range of motion if the biceps were inserted several inches distal (or proximal) from the actual position. 4. When describing different muscles in the body, try to get class names that indicate locations, properties, etc. You have to answer: "across". Then ask, "In what general area of ​​the body is this muscle located?" Answer: “Abs”. Finally ask, “What if

Copyright © 2010 Pearson Education, Inc.

Chapter 10

the muscular system

A logical name for this muscle? This type of logic can be applied to many cases and helps students to master information instead of just memorizing it.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Choose a volunteer and ask them to bend an arm or a leg. Have students record: main drivers, synergists, and antagonists. 3. Obtain a preserved stuffed animal, e.g. B. a cat or a fetal pig and show the most important muscle groups. 4. Have students work in pairs as follows: one student tries to contract a specific muscle while the second student resists to prevent the movement. This is how the muscle produces its maximum "mass". Both students should palpate the muscles to be examined in the relaxed and contracted states. For example, the "demonstrator" may attempt to bend the elbow while the resister holds the forearm to prevent movement. The biceps brachii at the front of the arm will be prominent and easily palpable. 5. While the muscles are being described, create Project 2 2 cadaver dissection slides so that students can easily see “the real thing” when presenting the material in class. The micro-projector can function throughout the lesson, with cues placed in the lesson notes as to when specific slides should be shown. 6. Create a 3D model or graphic to illustrate the major human muscle groups. 7. Gather tools like scissors, wheelbarrows, and tweezers to illustrate the three types of lever systems. 8. Obtain a human corpse to illustrate the main human muscle groups.

Critical Thinking/Points for Discussion 1. Why is it necessary for pregnant women to strengthen their 'pelvic floor'? 2. What is it about bones that allows them to act as effective levers? 3. What are the most appropriate forms of therapy for muscle strain or groin strain? 4. Injections are often made directly into muscle tissue. What are the pros and cons? 5. When a prime mover such as the pectoralis major is surgically removed, how are the actions provided by that muscle replaced? 6. How would an upper limb be designed to function with a relatively greater degree of mechanical advantage than currently exists?

Library Research Topics 1. Since muscle cells do not regenerate, what treatments are available when a large muscle group is lost? What is the status of skeletal muscle transplants? 2. How does age affect skeletal muscle? What kind of research is done on this topic? 3. Different sports require different training methods. Compare and differentiate the training methods of athletes in different sports.

Copyright © 2010 Pearson Education, Inc.

121

122

Text and media manual Human anatomy and physiology 4. Some muscle groups, such as the triceps surae, have individual muscles with predominantly different fiber types. In order to build these muscles evenly, the group should be trained with combined isometric-isotonic exercises. Find out how these exercises work.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all of the chapter-specific online media resources for Chapter 10 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives of muscle review Section 10.1 Skeletal muscle interactions in the body (p. 321) Section 10.2 Skeletal muscle nomenclature (pp. 321–322) Section 10.3 Muscle mechanics: importance of fascicle arrangement and leverage (pp. 322–324) Muscles Bodies Skeletons (p. 324 –382) A&P Flix Animations: Muscle Actions and Joint Movements A&P Flix Animations: Origins, Insertions, Actions, and Innervations Artist's caption: Anterior view of the superficial muscles of the body (Fig. 10.4, p. 326 ) Artist's caption: Posterior view of the superficial muscles of the body (Fig. 10.5 , p. 327) Artist's caption: Side view of muscles of scalp, face and neck (Fig. 10.6, p. 331) Artist's caption: Muscles of neck and cervical spine cause head and trunk movements (Fig. 10.9a, p 337) Artist's caption: Abdominal wall muscles (Fig. 10.11a, p. 3-43) Artist's caption: Muscles of the hand, ventral view of the right hand (Fig. 10.18a, p. 361) Art Labeled: Anterior and medial muscle movements of thigh and leg (Fig. 10.19a, p. 364) Art Labeled: Posterior hip and thigh muscles (Fig. 10.20a, c, pp. 367–368) Art Labeled: Anterior compartment muscles of the right leg (Fig. 10.21a, p. 371) Art . Label: Muscles of the lateral compartment of the right leg (Fig. 10.22, p. 372) Artist's label: Muscles of the posterior compartment of the right leg (Fig. 10.23a–c, pp. 374–375) Artist's label: Muscles of the right foot, plantar ( Fig. 10.24a-b, p. 377) Art Caption: Muscles of the right foot, plantar (Fig. 10.24c, p. 379) Art Caption: Summary of the actions of the thigh muscles ( Fig. 10.25a, ​​p. 381) Artist Caption: Summary of leg muscle actions (Fig. 10.25b, p. 381)

Copyright © 2010 Pearson Education, Inc.

Chapter 10

the muscular system

Memory Game: Identifying Skeletal Muscle Memory Game: Identifying Dissected Skeletal Muscle Chapter Summary Crossword 10.1 Crossword 10.2 Muscle Review Web Links Chapter Tests Art Labeling Test Matching Test Multiple Choice Test True Test - Chapter Test Fake Study Tools Histology Atlas myeBook Flashcards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Slides 1. Human Muscle Tissue Assemblage (CBS). This collection of 6 slides covers the 3 muscle types.

Video 1. Human Muscle Videotape (BC; 23 min., 1999). Rose Leigh Vines, California State University. It offers a clear 23-minute anatomical tour of the muscles of the human body; an inexpensive alternative to cadaver dissection. 2. Living and Dying with Muscular Dystrophy (ESF; 13 min, 2007). This ABC News program stars a young man who made a decision early on not to fall victim to Duchenne muscular dystrophy. 3. The skeletal and muscular system (NIMCO; 24 min). Demonstrates how the skeletal and muscular systems work together to provide the structure and shape of the body.

Software 1. A.D.A.M.® Interactive Anatomy® 4.0 (see full list on page 9 of this manual). 2. A.D.A.M.® MediaPro (see page 9 of this manual for a complete list). 3. A.D.A.M.® Anatomy Practice (see page 87 of this manual for a complete list).

Copyright © 2010 Pearson Education, Inc.

123

124

Human Anatomy and Physiology Instructor's Text and Media Guide 4. Practice Anatomy Lab™ 2.0: Human cadaver, anatomical models, fetal pig (see page 9 of this guide for a complete list). 5. The Ultimate Human Body, version 2.2 (see page 9 of this manual for the full list). 6. Interactive Physiology® System Set of 10: Muscular System (see page 112 of this manual for a complete list).

Materials to Improve Teaching Thumbnails of all figures in Chapter 10 can be found in Appendix B.

Instructor Transparency Index/Resource DVD Figure 10.1 Figure 10.2 Figure Figure Figure Figure Figure Figure

10,3 10,4 10,5 10,6 10,7 10,8 10,9

figure figure figure figure

10,10 10,11 10,12 10,13

Figure 10.14 Figure 10.15 Figure 10.16 Figure 10.17 Figure 10.18 Figure 10.19 Figure 10.20 Figure 10.21 Figure 10.22 Figure 10.23 Figure 10.24 Figure 10.25 Table 10.1 Table 10.2 Table 10.3 Table 10.4

Arrangement pattern of fascicles in muscles. Leverage systems that work with mechanical advantage and mechanical disadvantage. lever systems. Front view of the superficial muscles of the body. Posterior view of the superficial muscles of the body. Side view of the muscles of the scalp, face and neck. Muscles that promote chewing and tongue movements. Muscles in the front of the neck and throat that promote swallowing. Muscles of the neck and spine that cause head and trunk movements. respiratory muscles. muscles of the abdominal wall. Muscles of the pelvic floor and perineum. Superficial muscles of the rib cage and shoulder that act on the scapula and arm. Muscles that cross the shoulder and elbow joint and cause movement of the arm and forearm respectively. Muscles of the anterior fascial compartment of the forearm that act on the right wrist and fingers. Muscles of the posterior fascial compartment of the right forearm that act on the wrist and fingers. Summary of the actions of the muscles of the arm and forearm. Muscles of the hand, anterior view of the right hand. Front and middle muscles that promote movement of the thighs and legs. Posterior muscles of the right hip and thigh. Muscles of the anterior compartment of the right leg. Muscles of the lateral compartment of the right leg. Muscles of the posterior compartment of the right leg. Muscles of the right foot, plantar aspect. Summary of the actions of the muscles of the upper and lower leg. Head muscles, part I: facial expression (Fig. 10.6) Head muscles, part II: chewing and tongue movement (Fig. 10.7) Anterior neck and pharynx muscles: swallowing (Fig. 10.8) Neck and spine: head movements and trunk extension (Fig. 10.9)

Copyright © 2010 Pearson Education, Inc.

Chapter 10 Box 10.5 Box 10.6 Box 10.7 Box 10.8 Box 10.9 Box 10.10 Box 10.11 Box 10.12 Box 10.13 Box 10.14 Box 10.15 Box 10.16 Box 10.17

the muscular system

Thoracic muscles: breathing (Fig. 10.10) Abdominal wall muscles: trunk movements and compression of the abdominal viscera (Fig. 10.11) Pelvic floor and perineum muscles: support of the abdominal organs (Fig. 10.12) Superficial muscles of the thorax anterior and posterior: movements of the scapula (Fig. 10.13) Muscles Crossing the shoulder joint: movements of the arm (humerus) (Fig. 10.14) Muscles crossing the elbow joint: flexion and extension of the forearm (Fig. 10.14) Muscles of the forearm: movements of the wrist, hand and fingers (Fig. 10.15 and 10.16) Summary of the actions of the muscles acting on the arm, forearm and hand (Fig. 10.17) Intrinsic muscles of the hand: fine movements of the fingers (Fig. 10.18) Muscles crossing the hip and knee: thigh and leg movements (Figures 10.19 and 10.20) Leg muscles: ankle and toe movements (Figures 10.2 1 to 10.23) Intrinsic foot muscles: movement and support of the toe arches (Figures to 10.24) Summary ung of the main actions of the muscles acting on the thigh, leg and foot (Fig. 10.25)

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Essay Questions with Short Answers 17. Students' answers may vary. (pp. 321 and 322) a. Location of frontal occipital zygomatic muscle b. Muscle shape: rhomboids, serratus anterior, quadratus lumborum c. Relative size of pectoralis major and minor, peroneus longus and peroneus brevis d. Direction of muscle fibers: rectus abdominis, external oblique, superficial transverse perineum e. Number of Origins: Triceps brachii, Biceps femoris f. Origin/Insertion Site: Stylohyoid, Sternothyroidea, Coracobrachialis g. Muscle action: levator scapulae, pronator teres, flexor carpi radialis, adductor longus 18. First Class: Effort - Pivot - Load Second Class: Pivot - Load - Effort Third Class: Pivot - Effort - Load (p. 324 ) 19 When the load is far from the fulcrum and the force is applied near the fulcrum, the applied force must be greater than the load to be moved. This type of lever can be beneficial as it allows the load to be moved quickly over a long distance with minimal shortening of the muscle. (p. 323)

Copyright © 2010 Pearson Education, Inc.

125

126

Text and media Teacher's manual of human anatomy and physiology 20. Constrictor muscles of the pharynx (p. 335) 21. Nick: sternocleidomastoid. "Yes" nod: M. Sternocleidomastoidus and Splenius. (p. 336) 22. a. rectus abdominis, external oblique, internal oblique, transverse abdominal (p. 342) b. Each pair is cross-plied, providing strength in the same way that different grain directions in plywood make a thin piece of wood strong for its thickness. (p. 342) c. External oblique and internal oblique abdomen (p. 342) d. Rectus abdominis (p. 342) 23. Flexion of humerus: pectoralis major and deltoids Extension of humerus: latissimus dorsi and deltoids Abduction of humerus: deltoids Adduction of humerus: pectoralis major, latissimus dorsi Circumference of humerus: combination of all of the above rotation of the humerus lateral: infraspinatus and teres minor rotation of the humerus medial: subscapularis (p. 358) 24. a. Extensor carpi radialis longus and brevis (p. 356) b. Flexor digitorum profundus (p. 355) 25. Piriformis, obturator externus and internus, geminis and quadratus femoris (p. 366-368) 26. Adductors, pectineus and gracilis (p. 365) 27. a. Deltoids, vastus lateralis, gluteus maximus, gluteus medius (pp. 350, 365–366) b. The vastus lateralis is used on babies because the hip and arm muscles are underdeveloped. (p. 365) 28. a. Opponent pollicis, flexor pollicis, short (p. 360) b. supinator, abductor pollicis longus (p. 356) c. Flexor pollicis longus, flexor digitorum profundus (pp. 354–355) d. Biceps brachii, brachialis anterior (p. 353) e. Hyoglossus, styloglossus (p. 332) f. flexor hallucis brevis, adductor hallucis (p. 378) g. Gastrocnemius, soleus, flexor digitorum (p. 373) h. Gracilis, adductor longus, adductor magnus (p. 365) i. Semimembranosus, biceps femoris, semitendinosus (p. 369)

Critical Thinking Questions and Clinical Application 1. When the forearm is pronated, the biceps brachii, a major mover of forearm flexion, is unable to act. (p. 353) 2. Levator ani, coccyx and external urethral sphincter (p. 344) 3. There was a tear of the Achilles tendon or Achilles tendon. (p. 373) The calf appears swollen because the gastrocnemius muscle is no longer attached to the heel bone. 4. Peter was happy with Sue's performance. He winked at her and gave her an ok sign. (p. 330, 360) 5. a. second class lever b. Third Class Lever c. First Class Lever (p. 324) 6. Chao injured his adductors. This condition is called a sprained groin. (p. 365)

Copyright © 2010 Pearson Education, Inc.

Chapter 10

the muscular system

Recommended Reading Agur, A.M. and A.F. Dalley. Grant's Atlas of Anatomy. 12th edition. Baltimore: Lippincott Williams & Wilkins, 2009. Clement, CD Anatomy: a regional atlas of the human body. 5th ed. Baltimore: Lippincott Williams & Wilkins, 2007. Gray, H., et al. Grey's anatomy. 40th edition. London: Churchill Livingstone, 2009. Rohen, JW, C Yokochi, and E Lütjen-Drecoll. Color atlas of anatomy: a photographic study of the human body. 6th ed. Baltimore: Lippincott Williams & Wilkins, 2007.

Copyright © 2010 Pearson Education, Inc.

127

11

Fundamentals of the nervous system and nerve tissue

Learning objectives Functions and areas of the nervous system 1. Name the basic functions of the nervous system. 2. Explain the structural and functional divisions of the nervous system. Histology of Nervous Tissue 3. Name the types of neuroglia and their functions. 4. Define a neuron, describe its main structural components and assign a functional function to each. 5. Distinguish a nerve from a duct and between a nucleus and a ganglion. 6. Explain the importance of the myelin sheath and describe how it is formed in the central and peripheral nervous systems. 7. Classify neurons structurally and functionally. Membrane potentials 8. Define the resting membrane potential and describe its electrochemical basis. 9. Compare and contrast graded potentials and action potentials.

10. Explain how action potentials are generated and propagate along neurons. 11. Define absolute and relative refractory periods. 12. Define saltatoric conduction and compare it to conduction along myelinated fibers. The synapse 13. Define synapse. Distinguish between electrical and chemical synapses based on their structure and the way they transmit information. 14. Distinguish between excitatory and inhibitory postsynaptic potentials. 15. Describe how synaptic events are integrated and modified. Neurotransmitters and their receptors 16. Define neurotransmitters and name several classes of neurotransmitters. Basic concepts of neural integration 17. Describe general patterns of neural organization and processing. 18. Distinguish between serial and parallel processing. Developmental aspects of neurons 19. Describe how neurons develop and form synapses.

128 Copyright © 2010 Pearson Education, Inc.

Chapter 11

Fundamentals of the nervous system and nerve tissue

Suggested Lesson Plan I. Functions and Divisions of the Nervous System (pp. 386-387; Figs. 11.1 and 11.2) A. The central nervous system consists of the brain and spinal cord and is the command and integration center of the nervous system. nervous (p. 386; Figs. 11.1–11.2). B. The peripheral nervous system lies outside the central nervous system (pp. 386-387; Fig. 11.2). 1. The sensory or afferent department of the peripheral nervous system transmits impulses from sensory receptors located throughout the body to the central nervous system. 2. The motor or efferent division of the peripheral nervous system conducts impulses from the central nervous system to the effector organs, the muscles and glands. a. The somatic nervous system consists of somatic nerve fibers that transmit impulses from the CNS to the skeletal muscles and enable conscious control of motor activities. B. The autonomic nervous system is an involuntary system composed of visceral motor nerve fibers that regulate smooth muscle, cardiac muscle, and glandular activity.

II. Histology of Nervous Tissue (pp. 388-395; Figs. 11.3-11.5; Table 11.1) A. Neuroglia or glial cells are closely associated with neurons and form a protective and supportive network (pp. 388-389; Fig. 11.3) . 1. Astrocytes are glial cells of the CNS that regulate the chemical environment around neurons and the exchanges between neurons and capillaries. 2. Microglia are glial cells in the CNS that monitor health and perform defense functions for neurons. 3. Ependymal cells are glial cells in the CNS that line the central cavities of the brain and spinal cord and help circulate cerebrospinal fluid. 4. Oligodendrocytes are CNS glial cells that surround neuronal fibers and form myelin sheaths. 5. Satellite cells are glial cells of the PNS whose function is largely unknown. They are found around the cell bodies of neurons within ganglia. 6. Schwann cells or neurolemocytes are glial cells of the PNS that surround nerve fibers and form the myelin sheath. B. Neurons are specialized cells that transport messages throughout the body in the form of electrical impulses (pp. 389-395; Fig. 11.4-11.5; Table 11.1). 1. Neurons function optimally throughout life, are mostly amitotic, and have an exceptionally high metabolic rate that requires oxygen and glucose. a. The cell body of the neuron, also called the perikaryon or soma, is the main biosynthetic center, containing the usual organelles except for the centrioles. B. Dendrites are cellular processes that represent the receptive regions of the cell. C. Each neuron has a single axon that generates and conducts nerve impulses from the cell body to the axon terminals. i.e. The myelin sheath is a whitish, fatty, segmented covering that protects and insulates the axons and increases conduction velocity. 2. There are three structural classes of neurons. a. Multipolar neurons have three or more processes. B. Bipolar neurons have a single axon and dendrites.

Copyright © 2010 Pearson Education, Inc.

129

130

Text and media manual for instructors in human anatomy and physiology c. Unipolar neurons have a single process that extends from the cell body and is associated with receptors at the distal end. 3. There are three functional classes of neurons. a. Sensory or afferent neurons relay impulses from receptors to the CNS. B. Motor or efferent neurons conduct impulses from the CNS to effectors. C. Interneurons or association neurons conduct impulses between sensory and motor neurons or in the integrative pathways of the CNS.

3. Membrane Potentials (pp. 395-406; Figs. 11.6-11.15) A. Basic Principles of Electricity (p. 395) 1. Voltage is a measure of the difference in electric charge between two points, called the potential difference. 2. The flow of electric charge from one point to another is called current and depends on voltage and resistance (obstacle to current flow). 3. In the body, electrical currents are created by the movement of ions across cell membranes. B. The role of membrane ion channels (p. 395; Fig. 11.6) 1. The cell has many activated ion channels. a. Chemically activated (ligand-gated) channels open when the appropriate chemical binds. B. Voltage-gated channels open in response to a change in membrane potential. C. Mechanically closed channels open when a membrane receptor is physically deformed. 2. When ion channels are open, ions diffuse across the membrane and generate electrical currents. C. The resting membrane potential (pp. 396 and 398; Figs. 11.7 and 11.8) 1. The cell membrane of the neuron is polarized and has a more negative charge on the inside than on the outside. The magnitude of this electrical charge difference is the resting membrane potential. 2. The resting membrane potential is generated by differences in the ionic composition of intracellular and extracellular fluids and the differential permeability of the membrane to solutes. D. Membrane potentials acting as signals (pp. 398-404; Figs. 11.9-11.14) 1. Changes in membrane potential are used by neurons as communication signals. These can be caused by changes in the permeability of the membrane to any ion or changes in ion concentrations on either side of the membrane. 2. Changes in membrane potential relative to the resting membrane potential can be depolarizations, where the cell interior becomes less negative, or hyperpolarizations, where the cell interior becomes more negatively charged. 3. Stepped potentials are short-term local changes in membrane potentials. They can be depolarizations or hyperpolarizations and are crucial for generating action potentials. 4. Action potentials or nerve impulses occur in axons and are the main form of communication in neurons. a. Generation of an action potential involves a transient increase in Na permeability, followed by restoration of Na impermeability, and then a transient increase in K permeability.Copyright © 2010 Pearson Education, Inc. All rights reserved.

Chapter 11

Fundamentals of the nervous system and nerve tissue

B. The propagation or propagation of an action potential occurs when local currents in an area undergoing depolarization cause the previously adjacent area to depolarize. C. Repolarization, which restores the resting membrane potential, follows depolarization across the membrane. 5. A critical minimum or threshold of depolarization is defined by the amount of Na inflow at least equal to the amount of K outflow 6. Action potentials are all-or-nothing phenomena: they occur entirely in the case of a Threshold stimulus, or not, in the case of a subliminal stimulus. 7. The intensity of the stimulus is encoded in the frequency of the action potentials. 8. The refractory period of an axon is related to the time it takes for a neuron to generate another action potential. E. Conduction Velocity (pp. 404-406; Fig. 11.15) 1. Larger diameter axons conduct impulses faster than smaller diameter axons. 2. Myelinated axons conduct impulses relatively slowly, while myelinated axons have high conduction speeds.

4. The synapse (pp. 406-413; Figs. 11.16-11.19; Table 11.2) A. A synapse is a connection that mediates the transmission of information between neurons or between a neuron and an effector cell (p. 406; Fig. 11.16 ) . B. Neurons that conduct impulses into the synapse are presynaptic cells, and neurons that conduct impulses out of the synapse are postsynaptic cells (p. 406). C. Electrical synapses have neurons that couple electrically through protein channels, allowing the direct exchange of ions from one cell to another (p. 406). D. Chemical synapses are specialized in the release and uptake of chemical neurotransmitters (pp. 407-408; Fig. 11.17). E. The effects of neurotransmitters are terminated in three ways: degradation by enzymes in the postsynaptic cell or within the synaptic cleft; reuptake by astrocytes or by the presynaptic cell; or diffusion out of the synapse (p. 408). F. Synaptic delay is related to the time required for neurotransmitter release and binding (p. 408). G. Postsynaptic potentials and synaptic integration (pp. 408-413; Figs. 11.18-11.19; Table 11.2) 1. Neurotransmitters mediate graded potentials in the postsynaptic cell that can be both excitatory and inhibitory. 2. Postsynaptic neuron summation occurs in two ways: temporal summation, which occurs in response to multiple sequential neurotransmitter releases, and spatial summation, which occurs when the postsynaptic cell is simultaneously stimulated by multiple terminals. 3. Synaptic potentiation occurs when a presynaptic cell is repeatedly or continuously stimulated, resulting in increased neurotransmitter release. 4. Presynaptic inhibition occurs when another neuron inhibits the release of excitatory neurotransmitters from a presynaptic cell. 5. Neuromodulation occurs when a neurotransmitter acts through slow changes in the target cell's metabolism or when chemicals other than the neurotransmitter alter neuronal activity.

Copyright © 2010 Pearson Education, Inc.

131

132

Text and media guide to human anatomy and physiology

V. Neurotransmitters and their receptors (pp. 413-421; Fig. 11.20; Table 11.3) A. Neurotransmitters are one of the means of communication of neurons and have several chemical classes (pp. 413-419; Table 11.3). B. Functional classifications of neurotransmitters consider whether the effects are excitatory or inhibitory and whether the effects are direct or indirect (pp. 419-420). C. There are two main types of neurotransmitter receptors: channel-bound receptors mediate the direct action of the transmitter and cause brief, localized changes; and G protein-bound receptors mediate the indirect action of the transmitter, resulting in slow, sustained, and often diffuse changes (pp. 420–421; Figs. 11–20).

SEEN. Basic concepts of neuronal integration (pp. 421-423; Fig. 11.21-11.23) A. Organization of neurons: neuronal pools (pp. 421-422; Fig. 11.21) 1. Neural pools are functional groups of neurons that integrate incoming information receptors or other neuronal groups and forward the information to other areas. B. Types of circuits (p. 422; Fig. 11.22) 1. Divergent circuits or amplifiers are common in sensory and motor pathways. They are characterized in that an incoming fiber triggers reactions in an increasing number of fibers along the circuit. 2. Converging circuits are common in sensory and motor pathways. They are characterized by receiving inputs from many sources and presenting a bottleneck to a particular circuit, resulting in strong stimulation or inhibition. 3. Reverberation or resonant circuits are characterized by feedback from collateral axons to points upstream of the pathway, resulting in continuous stimulation of the pathway. 4. Post-discharge parallel circuits can perform complex activities and are characterized by the stimulation of multiple neurons arranged in parallel arrays by the stimulating neuron. C. Patterns of Neural Processing (pp. 422-423; Fig. 11.23) 1. Serial processing is illustrated by spinal reflexes and involves the sequential stimulation of neurons in a circuit. 2. Parallel processing results in inputs that stimulate many pathways simultaneously and are critical to higher-level mental functioning.

VIII. Developmental Aspects of Neurons (pp. 423-424; Fig. 11.24) A. The nervous system originates from a dorsal neural tube and neural crest, which begin as a layer of neuroepithelial cells and eventually develop into the CNS ( p. 423). ) . B. Differentiation of neuroepithelial cells occurs mainly in the second month of development (p. 423). C. The growth of an axon toward its target appears to be guided by the search for older neurons and glial cells, nerve growth factor and cholesterol from astrocytes, and tropical chemicals from the target cell (pp. 423-424). D. The growth cone is a growing tip of an axon. It collects chemicals from the environment, which the cell uses to gauge the pathway for further growth and synapse formation (p. 424; Figs. 11-24). E. Failed synapse formation leads to cell death, and some degree of apoptosis occurs before the final population of neurons is complete (p. 424).

Copyright © 2010 Pearson Education, Inc.

Chapter 11

Fundamentals of the nervous system and nerve tissue

Cross-references For more information on the topics covered in Chapter 11, see the chapters listed below. 1. Chapter 2: Enzymes and enzyme function 2. Chapter 3: Passive and active membrane transport processes; membrane potential; elements of the cytoskeleton; cell cycle 3. Chapter 4: nerve tissue 4. Chapter 9: synapse (neuromuscular synapse) 5. Chapter 13: membrane potentials; Neuronal integration 6. Chapter 14: Cholinergic and adrenergic receptors and other effects of neurotransmitters; Autonomic Synapses 7. Chapter 15: Receptors for the Special Senses; synapses involved in special senses; Neurotransmitters in the Special Senses 8. Chapter 16: Nervous System Modulation of Endocrine Function 9. Chapter 18: Membrane Potential and Electrical Activity of the Heart 10. Chapter 19: Baroreceptors and Chemoreceptors in Regulation of Blood Pressure and Flow 11 Chapter 22: Chemoreceptors and Stretch Receptors Related with the respiratory function 12. Chapter 23: Sensory receptors and control of digestive processes 13. Chapter 24: Examples of receptors

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 17: Nerve Tissue Histology Exercise 18: Neurophysiology of Nerve Impulses PhysioEx™ 8.0 Exercise 18B: Neurophysiology of Nerve Impulses: Computer Simulation 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 17: Nerve Tissue Histology Exercise 18: Neurophysiology of Nerve Impulses PhysioEx™ 8.0 Exercise 18B: Neurophysiology of Nerve Impulses: Computer Simulation

Tips for Lesson 1. At this point the class has only been exposed to a few systems (skin, skeletal and muscular), but enough information has been provided for students to understand the basics of how the nervous system works from the very beginning of this department. Ask students questions such as: (1) How do you react when you touch something hot? (2) Do you have to consciously remember to draw your hand? The idea of ​​these basic questions is to get students to understand the idea that a neural pathway consists of a sensory structure, some means of transmitting information to the brain, and some means of eliciting a motor response. If you can get students to think of these "solutions," they will remember the logic used to arrive at the answers. 2. Emphasize the three basic functions of the nervous system: sensory, integrative, and motor. The students have to “memorize” this, because it will show up again and again in all systems. Copyright © 2010 Pearson Education, Inc.

133

134

Text and Media Human Anatomy and Physiology Teacher Guide 3. Emphasize that although we have discussed it in sections, the nervous system is actually tightly integrated. 4. To begin the discussion of the nervous system, provide a general introduction to the overall nervous system so students can see the big picture. This way they will understand the connections better when the material is covered. 5. Point out the similarities between skeletal muscle cells and neurons. It is also possible to introduce the electrical properties of pacemaker cells (modified muscle cells) and observe the similarities with the function of neurons. Mention that although the function is wildly different (muscle contraction, nerve impulse generation, propagation), the structural basis of each is a slight modification of a basic cellular design. 6. Bring a model (or slides, 2 2 slides) of a neuron to the conference to visually demonstrate the anatomy of a nerve cell. 7. Many students have difficulty understanding the difference between the myelin sheath and the neurilemma (Schwann's sheath). Use a chart (black line master) to indicate that both are parts of the same cell. 8. Emphasize the difference in myelination between the CNS and PNS. Indicate the regenerative capacity of each. 9. Many students have difficulty relating the motion of ions to electric current. One way to approach neurophysiology is to compare (in general terms) a 1.5V battery to the cell membrane. The electrical potential between the plus and minus poles is analogous to the outside and inside of a cell. When a connection is made between the positive and negative poles (open ion gates), current is supplied. 10. Clearly distinguish the difference between graded potentials and action potentials. It is useful to use an overhead from a full-page neuron to demonstrate the positive feedback nature of the action potential. 11. Most introductory physiology students will struggle with the idea of ​​saltatory conduction. Draw (or project) diagrams of myelinated versus unmyelinated fibers and electrical propagation. 12. Draw a diagram of a synapse, then use the stem dissection to emphasize the distinction between presynaptic and postsynaptic neurons. This is a good introduction to synapse and provides a foundation for students to build upon. 13. Use absolute numbers as an introductory example of addition. Example: If three presynaptic neurons simultaneously deliver a third of the threshold stimulus, will the postsynaptic neuron then fire? Use several examples to emphasize the difference between spatial and temporal addition. 14. Use diagrams when describing different types of circuits.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Obtain a microprojector and slides of neurons, neuroglia, and peripheral nerves to visualize the histology of the tissue. 3. Obtain an oscilloscope and neurophysiology kit to illustrate how an action potential can be recorded. 4. Obtain three-dimensional models of sensory and motor neurons to illustrate their similarities and differences. 5. Use a correspondence to illustrate how an EPSP can work and how a graded potential will be strong on the receiver side and decrease from there. Then use a fuse wire to illustrate how an action potential is transmitted down the wire.

Copyright © 2010 Pearson Education, Inc.

Chapter 11

Fundamentals of the nervous system and nerve tissue

Critical Thinking/Discussion Points 1. How can drugs like Novocaine effectively block the transmission of pain impulses? Why don't they block motor impulses, or do they? 2. What effect does alcohol have on the transmission of electrical impulses? 3. How does nose rubbing reduce the risk of sneezing? Analyze in terms of EPSP and IPSP. 4. Acetylcholine has long been recognized as a neurotransmitter. Why was it so difficult to identify other neurotransmitters? 5. How can some people eat extremely hot peppers without feeling the same pain that others usually feel? 6. What would happen in a synapse if a drug were introduced that blocks the activity of chemically activated Na channels? K channels?

Library Research Topics 1. What is the value of developing recombinant DNA technology in our study of protein-based neurotransmitters? 2. What is the current state of research on the repair and/or regeneration of nerve tissue in the CNS? 3. Why do most neural tissue tumors develop in neuroglia and not in neurons? 4. Could we use neurotransmitters to increase our memory capacity? 5. How are experiments conducted to test the anatomy and physiology of plasma membrane gates and ion channels?

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all of the chapter-specific online media resources for Chapter 11 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 11.1 Functions and areas of the nervous system (pp. 386-387) Physiology® Interactive System Set of 10: Nervous System I: Orientation Section 11.2 Histology of Nervous Tissue (pp. 388-395) Physiology Interactive System Set of 10 ® : Nervous System I: Anatomy Review (Neurons) Memory Game: Neural System Section 11.3 Membrane Potentials (pp. 395-406) MP3 Tutorial Session: Generation of an Action Potential Interactive Physiology® 10 System Set: Nerve I : Physiology of Interactive Ion Channels ® 10 System Set: Nervous I: membrane potential

Copyright © 2010 Pearson Education, Inc.

135

136

Text and Media Human Anatomy and Physiology Instructor Manual 10-System Interactive Set Physiology®: Nervous I: Action Potential Memory Game: Action Potential Propagation PhysioEx™ 8.0: Neurophysiology of Nerve Impulse Section 11.4 The Synapse (pp. 406-413) A&P Flix Animation : Neurophysiology of Nerve Impulses Interactive Physiology® 10 System Suite: Nervous System II: Anatomical Overview (Synapses) Interactive Physiology® 10 System Suite: Nervous System II: Ion Channels Interactive Physiology® 10 System Suite: Nervous System II: Synaptic Transmission Interactive Physiology® 10 -System Suite: Nervous system II: synaptic potentials and cellular integration Section 11.5 Neurotransmitters and their receptors (pp. 413-421) Section 11.6 Basic concepts of neuronal integration (pp. 421-423) Section 11.7 Developmental aspects of neurons (pp. 423-424) Case Study: Birth Defects Chapter Summary o Crossword 11.1 Crossword 11.2 Word c 11.3 Crossword 11.4 Cr euzworträtsel 11.5 Web links Chapter tests Art lettering test Assignment test Multiple choice test Chapter Practice test Practice test Learning tools Histology atlas myeBook Flashcards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Slides 1. Human nerve tissue (CBS) kit. A collection of 25 slides provides comprehensive coverage of the nervous system.

Copyright © 2010 Pearson Education, Inc.

Chapter 11

Fundamentals of the nervous system and nerve tissue

Video 1st decision (ESF; 28 min., 1984). This show from The Living Body shows how the brain works in a coordinated manner to make a simple but life-saving decision. 2. The human nervous system: the brain and cranial nerve videotape (BC; 28 min., 1997). This video by Rose Leigh Vines and Rosalee Carter of California State University, Sacramento lists the structures and functions of the nervous system. 3. The Human Nervous System: Videotape of the Spinal Cord and Nerves (BC; 29 min, 1997). Illustrations and figures help students learn the organization of the spinal nerves into intricate plexuses. The major nerves that arise from these plexuses are traced in the cadaver as they pass through the upper and lower extremities. 4. The nervous system: neurons, networks, and the human brain (IM; 32 min, 2007). This program examines the structures and functions of neurons. Introduces the peripheral, somatic, autonomic, sympathetic, parasympathetic, and central nervous systems. It also discusses the structures and functions of the human spinal cord and brain. 5. The Nervous System: The Ultimate Control Center (IM; 20 min., 2001). It examines the structural and functional classifications of the brain and addresses homeostatic imbalances such as Parkinson's and stroke. 6. Wired (LM; 27 mins, 2001). Through an examination of "Phantom Limb Syndrome," this video examines the structure and function of the body's nervous system.

Software 1. Set of 10 Interactive Physiology® Systems: Nervous System I and II (BC; Win/Mac, 2009). Provides detailed information on neurons, resting membrane potential, and action potential generation/propagation within the nervous system. Topics covered include ion channels, membrane potential, and action potential. 2. Practice Anatomy Lab™ 2.0: Human cadaver, anatomical models, histology (see full list on page 9 of this manual).

Material to improve the lesson Thumbnails of all illustrations in Chapter 11 can be found in Appendix B.

Index Instructor Slide/Resource DVD Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure

11,1 11,2 11,3 11,4 11,5 11,6 11,7 11,8 11,9 11,10 11,11 11,12 11,13 11,14 11,15

The functions of the nervous system. Diagram of the levels of organization of the nervous system. neuroglia. Structure of a motor neuron. Myelination of nerve fibers by Schwann cells in the PNS. Operation of closed channels. Measurement of membrane potential in neurons. Resting membrane potential Depolarization and hyperpolarization of the membrane. Propagation and decay of a graded potential. Action potential Propagation of an action potential. Relationship between the intensity of the stimulus and the frequency of the action potential. Absolute and relative refractory periods in a PA. Action potential propagation in myelinated and unmyelinated axons. Copyright © 2010 Pearson Education, Inc.

137

138

Text and media manual for teachers of human anatomy and physiology

synapse. Chemical Synapse Postsynaptic Potentials. Neural integration of EPSPs and IPSPs. Direct and indirect mechanism of neurotransmitter receptor. Simple neural ensemble. Types of Circuits in Neural Pools. A simple reflex arc. A neural growth cone. Comparison of structural classes of neurons Comparison of action potentials with graded potentials Neurotransmitters and neuromodulators Please pass on!

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 13. The anatomical department includes the CNS (brain and spinal cord) and the PNS (nerves and ganglia). The functional department includes the somatic and autonomic motor departments of the PNS. The vegetative part is divided into sympathetic and parasympathetic. (p. 386 and 387) 14. a. The cell body is the biosynthetic and metabolic center of a neuron. Contains the usual organelles but no centrioles. (pp. 389-390) b. Dendrites and axons serve to carry electrical current. The dendrites differ in that they are short, transferred to the cell body, and function as receptor sites. The axons are normally long, myelinated, and radiate out from the cell body. Only axons can generate action potentials, the long-distance signals. (pp. 390 and 391) 15. a. Myelin is a whitish fatty material that insulates phospholipids (basically the plasma membranes that surround oligodendrocytes, or Schwann cells). B. The myelin sheaths of the CNS are formed by patchy extensions of oligodendrocytes and lack a neurilemma. Each oligodendrocyte can help myelinate different fibers. The myelin of the PNS consists of Schwann cells; the involvement of each Schwann cell forms the internode region. The pods have a neurilemma and the fibers that protect them are capable of regeneration. (pp. 391-392) 16. Multipolar neurons have many dendrites, one axon, and are found in the CNS (and autonomic ganglia). Bipolar neurons have an axon and a dendrite and are located in end organs that receive specialized senses, such as the retina of the eye and the olfactory mucosa. Unipolar neurons have a process that divides into an axon and a dendrite and is a sensory neuron whose cell body is located in a spinal ganglion or a cranial nerve ganglion. (pp. 392-393; Table 11.1) 17. A polarized membrane has a net positive charge on the outside and a net negative charge on the inside, with a voltage across the membrane of 70 mV. The diffusion of Na and K through the membrane establishes the resting potential, since the membrane is somewhat more permeable to K. The Na-K pump, an active transport mechanism, maintains this polarized state by maintaining the diffusion gradient of Na and K (p. 396)

Copyright © 2010 Pearson Education, Inc.

Chapter 11

Fundamentals of the nervous system and nerve tissue

18. a. The generation of an action potential involves: (1) increased sodium permeability and inversion of the membrane potential; (2) a decrease in sodium permeability; and (3) an increase in potassium permeability and repolarization. (pp. 399-402) b. Ion gates are controlled by changes in membrane potential and activated by local currents. C. The all-or-nothing phenomenon means that the local depolarizing current must reach a critical threshold or "trigger point" before it reacts, and when it reacts, it will do so completely, using the action potential along its entire length axon drives . (pp. 403-404) 19. The CNS "knows" that a stimulus is strong when the frequency or rate of generation of the action potential is high. (p. 404) 20. a. An EPSP is an excitatory (depolarizing) postsynaptic potential that increases the likelihood of a depolarizing event. An IPSP is an inhibitory (hyperpolarizing) postsynaptic potential that reduces the likelihood of a depolarizing event. (pp. 411 and 412) b. It is determined by the type and amount of neurotransmitter that binds to the postsynaptic neuron and the specific receptor subtype to which it binds. (pp. 411-413) 21. The axonal pons of each neuron maintains a "running count" of all the signals it receives by adding temporal and spatial summation. (p. 412) 22. The neurotransmitter is rapidly removed by enzymatic degradation or reuptake into the presynaptic axon. This ensures discretely limited reactions. (p. 408) 23. a. The A fibers have the largest diameter and thick myelin sheaths and transmit impulses quickly; B fibers are slightly myelinated, have intermediate diameters, and conduct more slowly. (p. 406) b. The absolute refractory period is when the neuron cannot respond to another stimulus because the sodium gates are still open or inactive. (p. 404) c. A Ranvier nodule is a disruption in the myelin sheath between individual Schwann cell envelopes or oligodendrocyte processes. (p. 391) 24. In serial processing, the path is constant and runs through a defined sequence of neurons; The answer is predictable and formulaic. In parallel processing, impulses reach their final destination in the CNS via multiple paths. Parallel processing allows for a variety of responses. (p. 423) 25. First, they multiply; second, they migrate to the correct position; Third, they differ. (pp. 423-424) 26. Axon development relies on chemical signals from neurotropin and NGF, which interact with receptors on the developing axon to support and guide its growth. (p. 424)

Critical Thinking Issues and Clinical Application 1. The resting potential would decrease, that is, become less negative, because the concentration gradient causing the net diffusion of K out of the cell would be smaller. Action potentials would be triggered more easily, that is, in response to smaller stimuli, since the resting potential would be closer to threshold. Repolarization would occur more slowly because repolarization depends on the net diffusion of K out of the cell and the concentration gradient driving this diffusion is smaller. In addition, the subsequent hyperpolarization would be less. (pp. 396-398) 2. Local anesthetics, such as novocaine and tranquilizers, affect neural processes, usually in the Ranvier nodes, by reducing membrane permeability to sodium ions. (p. 402) 3. Bacteria remain in the wound; However, the toxin produced travels via axonal transport to reach the cell body. (p. 391) 4. In MS, the myelin sheaths are destroyed. The loss of this insulating envelope leads to a current shunt and ultimately the termination of neurotransmission. (pp. 405-406) Copyright © 2010 Pearson Education, Inc.

139

140

Text and Media Human Anatomy and Physiology Teacher's Guide 5. Glycine is an inhibitory neurotransmitter used to modulate transmission in the spinal cord. Strychnine blocks the glycine receptors in the spinal cord, causing dysregulated muscle stimulation and spastic contraction to the point where the muscles cannot relax. (p. 417; Box 11.3)

Suggested Reading Aldrich, Richard W. "Fifty Years of Inactivation". Nature 411 (6838) (2001 June): 643-644. Barres, Ben A. and Stephen J. Smith. "Cholesterol: Make or break the synapse". Science 294 (5545) (November 2001): 1296-1297. Bertram, John S. "Cellular Communication Through Gap Junctions." Science and Medicine 7(2) (March/April 2000): 18-27. Brown, Anton. "Slow axonal transport: stop-start traffic on the axon". Nature Reviews: Molecular Cell Biology 1(2) (November 2000): 153-156. Fernández-Chacon, Rafael, et al. "Synaptotagmin I acts as a regulator of the likelihood of calcium release". Nature 410 (6824) (March 2001): 41-48. Gallo, Vittoria and Ramesh Chittajallu. "Unpacking glial cells from the synapse: what's inside?" Science 292 (5518) (May 2001): 872-873. Giaume C, F Kirchhoff, C Matute, A Reichenbach, and A Verkhratsky. "Glia: the linchpin of brain disease". Cell Death and Differentiation 14 (April 2007): 1324-1335. Haydon, Philip G. "Glia: Listening and Talking to the Synapse." Nature Reviews: Neuroscience 2 (3) (March 2001): 185-192. Helmut, Laura. "Glia tells the neurons to build synapses." Science 291 (5504) (January 2001): 569-570. Hoppe, C. and J. Stojanovic. "High Aptitude Minds: The Neurological Roots of Genius". Scientific American Mind 19(4) (September 2008): 60-67. Casta, Ben. "Best Supporting Actors." Nature 412 (6848) (Aug 2001): 674–676. Khakh, Baljit S. "Molecular physiology of P2X receptors and ATP signaling at synapses." Nature Reviews: Neuroscience 2 (3) (March 2001): 165-174. Magee, Jeffery C. "Dendritic Integration of Excitatory Synaptic Input." Nature Reviews: Neuroscience 1 (3) (December 2000): 181-190. McBain, Chris J., and Andre Fisahn. "Loose interneurons". Nature Reviews: Neuroscience 2(1) (January 2001): 11-22. Muller, Christopher. "See Potassium Rush". Nature 414 (6859) (November 2001): 23–24. Nestler, Eric J. "Total Recall: The Recollection of Addiction." Science 292 (5525) (2001 June): 2266-2267. Rash, John and others. "Mixed synapses discovered and mapped along the mammalian spinal cord". Proceedings of the National Academy of Sciences 93 (April 1996): 4235-4239. Schmitz, Dietmar, et al. "Axo-axonal coupling: a novel mechanism for ultrafast neural communication". Neuron 31 (September 2001): 831-840. Spruston, Nelson. "Axonal gap junctions send waves across the hippocampus". Neuron 31 (September 2001): 669-675. Stix, Gary. "Say yes to no." Scientific American 285(5) (November 2001): 34.

Copyright © 2010 Pearson Education, Inc.

the central nervous system

12

16. Describe the relative roles of the major brain structures thought to be involved in declarative and procedural memories.

Aims The Brain 1. Describe the process of brain development. 2. Name the main regions of the adult brain. 3. Name and locate the ventricles of the brain. 4. Name the main lobes, fissures and functional areas of the cerebral cortex. 5. Explain the lateralization of the function of the hemisphere. 6. Distinguish between commissures, association fibers and projection fibers. 7. Describe the general function of the basal ganglia (basal ganglia). 8. Describe the location of the diencephalon and name its subdivisions and functions. 9. Identify the three main regions of the brainstem and write down the functions of each region. 10. Describe the structure and function of the cerebellum. 11. Locate the limbic system and the reticular formation and explain the role of each functional system. Higher Mental Functions 12. Define EEG and distinguish between alpha, beta, theta and delta brainwaves. 13. Describe the consciousness clinically. 14. Compare and differentiate the events and meaning of REM and slow wave sleep and indicate how their patterns change throughout life. 15. Compare and contrast stages and categories of memory.

Protection of the brain 17. Describe how the meninges, cerebrospinal fluid and blood-brain barrier protect the CNS. 18. Describe the formation of cerebrospinal fluid and follow its circulation. 19. List the cause (if known) and major signs and symptoms of stroke, Alzheimer's disease, Parkinson's disease and Huntington's disease. The spinal cord 20. Describe the embryonic development of the spinal cord. 21. Describe the macroscopic and microscopic structure of the spinal cord. 22. List the main pathways of the spinal cord and classify each as motor or sensory. 23. Distinguish between flaccid and spastic paralysis and between paralysis and paresthesia. Diagnostic methods for assessing CNS dysfunction 24. Name and explain different techniques for diagnosing brain diseases. Aspects of central nervous system development 25. List several maternal factors that can influence the development of the nervous system in an embryo. 26. Explain the effects of aging on the brain.

141 Copyright © 2010 Pearson Education, Inc.

142

Text and media guide to human anatomy and physiology

Suggested Lesson Plan I. The Brain (pp. 430-453; Figs. 12.1-12.4; Table 12.1) A. Embryonic Development (pp. 430-431; Figs. 12.1-12.4) 1. At the 3rd week of gestation, the ectoderm forms the Neural plate, which invaginates to form the neural groove and is flanked by neural folds on both sides. 2. In the fourth week of gestation, the neural groove fuses, creating the neural tube, which rapidly differentiates in the CNS. 3. The neural tube develops narrowings that divide the three primary cerebral sacs: the prosencephalon (forebrain), the midbrain (midbrain), and the rhombencephalon (hindbrain). B. Regions and organization (p. 431) 1. The basic pattern of the CNS consists of a central cavity surrounded by a gray matter nucleus, outside which is white matter. 2. In the brain, the cerebrum and cerebellum have an outer layer of gray matter that is reduced to scattered gray matter nuclei in the spinal cord. C. Ventricles (pp. 431-433; Fig. 12.5) 1. The ventricles of the brain merge into one another and into the central canal of the spinal cord. They are lined with ependymal cells and filled with cerebrospinal fluid. a. The paired lateral ventricles lie deep in each cerebral hemisphere and are separated by the septum pellucidum. B. The third ventricle is located in the diencephalon and communicates with the lateral ventricles through two interventricular foramina. C. The fourth ventricle lies in the rhombencephalon and communicates with the third ventricle through the cerebral aqueduct. D. Cerebral Hemispheres (pp. 433-441; Figs. 12.6-12.11; Table 12.1) 1. The cerebral hemispheres form the upper part of the brain and are characterized by ridges and grooves called gyri and sulci. 2. The cerebral hemispheres are separated from the cerebellum along the midline through the longitudinal cleft and through the transverse cleft of the brain. 3. The five brain lobes, separated by specific grooves, are: frontal, parietal, temporal, occipital, and insular. 4. The cerebral cortex is the site of consciousness that enables us to communicate, remember, and understand. 5. The cerebral cortex has several motor areas in the frontal lobes that control voluntary movements. a. The primary motor cortex enables conscious control of the dexterous voluntary movement of skeletal muscles. B. The premotor cortex is the region that controls learned motor skills. C. Broca's area is a language-motor area that controls the muscles involved in language production. i.e. The frontal eye field controls the movement of the eyes. 6. There are several sensory areas of the cerebral cortex found in the parietal, temporal and occipital lobes. a. The primary somatosensory cortex allows for spatial discrimination and the ability to recognize the location of stimulation.

Copyright © 2010 Pearson Education, Inc.

Chapter 12

the central nervous system

B. The somatosensory association cortex integrates sensory information and generates an understanding of the stimulus felt. C. The primary visual cortex and visual association area allow for the reception and interpretation of visual stimuli. i.e. The primary auditory cortex and auditory association area enable recognition of sound characteristics and contextual recognition. Y. The olfactory cortex enables the perception of smells. F. The taste cortex enables the perception of taste stimuli. Grams. The vestibular cortex is responsible for the conscious perception of balance. 7. Several association areas are not connected to any sensory cortex. a. The prefrontal cortex is involved in intellect, cognition, memory and personality and is closely connected to the limbic system. B. Language areas involved in comprehension and articulation include Wernicke's area, Broca's area, the lateral prefrontal cortex, and the lateral and ventral temporal lobes. C. The posterior associative area receives information from all sensory areas and integrates signals into a single thought. i.e. The visceral association area is involved in conscious visceral sensation. 8. There is a lateralization of cortical function, where each cerebral hemisphere has unique capabilities not shared by the other half. a. One hemisphere (usually the left) dominates language, math, and logical skills, and the other hemisphere (usually the right) dominates visuo-spatial skills, intuition, emotions, and artistic and musical skills. 9. The white matter of the brain is responsible for communication between the brain areas and the cerebral cortex and the lower centers of the CNS. 10. The basal ganglia consists of a group of subcortical nuclei that play a role in motor control and regulate attention and cognition. E. The diencephalon is a collection of areas of gray matter and consists of the thalamus, hypothalamus, and epithalamus (pp. 441-445; Figs. 12.11-12.15; Table 12.1). 1. The thalamus plays a key role in mediating sensation, motor activity, cortical arousal, learning, and memory. 2. The hypothalamus is the body's control center and regulates ANS activity such as emotional response, body temperature, food intake, sleep-wake cycles and endocrine function. 3. The epithalamus includes the pineal gland, which secretes melatonin and regulates the sleep-wake cycle. F. The brainstem, composed of the midbrain, pons, and medulla oblongata, produces rigidly programmed automatic behaviors necessary for survival (pp. 445-450; Figs. 12.15-12.16; Table 12.1). 1. The midbrain consists of the brain pedicles, the quadrigeminal bodies, and the substantia nigra. 2. The bridge contains fibrous pathways that complete the pathways between the brain and spinal cord. 3. The medulla oblongata is the site of several visceral motor nuclei that control vital functions such as heart rate and respiration. G. Cerebellum (pp. 450-451; Fig. 12.17; Table 12.1) 1. The cerebellum processes information from various structures and coordinates the contraction of skeletal muscles to produce smooth movement.

Copyright © 2010 Pearson Education, Inc.

143

144

Text and Media Teacher's Guide Human Anatomy and Physiology a. There are two cerebellar hemispheres, each consisting of three lobes. The anterior and posterior lobes coordinate body movements, and the floculonodular lobes adjust posture to maintain balance. B. Three paired bundles of fibers, the cerebellar peduncles, communicate between the cerebellum and the brainstem. 2. Cerebellum processing follows a functional scheme in which the frontal cortex communicates to the cerebellum intention to initiate voluntary movement, the cerebellum gathers information about balance and tension in muscles and ligaments, and how the activity can best be coordinated according to in front. the cerebral cortex H. Functional brain systems consist of neurons distributed throughout the brain but working together (pp. 451-453; Figs. 12.18-12.19). 1. The limbic system is involved in emotions and is widely wired throughout the brain, allowing it to integrate and respond to a wide variety of environmental stimuli. 2. The reticular formation extends through the brainstem, keeping the cortex on alert through the reticular activation system and dampening familiar, repetitive, or faint sensory inputs.

II. Higher Mental Functions (pp. 453-460; Figs. 12.20-12.23) A. Brain wave patterns and the EEG (pp. 453-455; Fig. 12.20) 1. Normal brain function results from continuous electrical activity of neurons and can be recorded with an electroencephalogram or EEG. 2. Patterns of electrical activity are called brain waves and are divided into four types: alpha, beta, theta and delta waves. B. Consciousness includes the conscious perception of sensations, the voluntary initiation and control of movement, and the associated higher mental processing abilities (p. 455). C. Sleep and Sleep-Wake Cycles (pp. 455-457; Fig. 12.21) 1. Sleep is a state of partial unconsciousness from which a person can be awakened and has two main types which alternate throughout the dream cycle a . Non-rapid eye movement (NREM) sleep consists of four phases. B. Most dreams occur during REM (Rapid Eye Movement) sleep. 2. Sleep patterns change throughout life and are regulated by the hypothalamus. 3. NREM sleep is considered restorative, and REM sleep allows the brain to analyze events or eliminate meaningless information. D. Memory is the storage and retrieval of information (pp. 457-460; Figs. 12.22-12.23). 1. Short-term memory or working memory makes it possible to remember some pieces of information for a short time. 2. Long-term memory allows potentially unlimited amounts of information to be stored for very long periods of time. 3. The transfer of information from short-term to long-term memory can be impaired by increased emotional state, repetition, associating new information with old information, or automatically forming memory when concentrating on something else. 4. Declarative memory involves learning explicit information, it is generally stored with the learning context and is related to the ability to manipulate symbols and language.

Copyright © 2010 Pearson Education, Inc.

Chapter 12

the central nervous system

5. Non-declarative memory usually involves motor skills, is often stored without details of the learning context, and is reinforced by performance. 6. Learning causes changes in neuronal RNA, dendritic branching, deposition of unique proteins at LTM synapses, enlargement of presynaptic endings, increase in neurotransmitters, and development of new neurons in the hippocampus.

3. Protection of the brain (pp. 460-466; Figs. 12.24-12.27) A. The meninges are three connective tissue membranes that cover and protect the CNS, protect blood vessels and enclose the venous sinuses, contain cerebrospinal fluid, and divide the brain and brain (pp. 461 to 463; Figures 12.24 to 12.25). 1. The dura mater is the more durable outer covering that extends inward in certain areas to limit movement of the brain within the skull. 2. The arachnoid is the middle meninges that form a loose lining of the brain. 3. The pia mater is the innermost layer that adheres firmly to the brain. B. Cerebrospinal fluid (p. 463; Figs. 12.26 and 12.27) 1. Cerebrospinal fluid (CSF) is the fluid that resides in the ventricles of the brain and surrounds the brain and spinal cord. 2. CSF gives the brain a boost, protects the brain and spinal cord from shock damage, and is a means of delivering nutrients and chemical signals. C. The blood-brain barrier is a mechanism that helps maintain a protective environment for the brain (pp. 463-464). D. Brain Homeostatic Imbalances (pp. 464-466) 1. Traumatic head injury can cause brain injuries of varying degrees of severity: concussion, contusion, and subdural or subarachnoid hemorrhage. 2. Cerebrovascular accidents (CVAs) or strokes occur when the blood supply to the brain is blocked, resulting in tissue death. 3. Alzheimer's disease is a progressive degenerative disease that leads to dementia. 4. Parkinson's disease results from impairment of the dopamine-secreting neurons of the substantia nigra, resulting in loss of coordination of movements and persistent tremors. 5. Huntington's disease is a fatal inherited disorder resulting from deterioration of the basal ganglia and cerebral cortex.

4. The spinal cord (pp. 466-477; Figs. 12.28-12.35; Boxes 12.2-12.3) A. Embryonic development (p. 466; Fig. 12.28) 1. The spinal cord develops from the caudal portion of the neural tube. 2. Axons from the alar plates form the white matter, and extension of the alar and ventral plates leads to the central gray matter of the medulla oblongata. 3. Neural crest cells form the spinal ganglia and send axons to the dorsal aspect of the spinal cord. B. General Anatomy and Protection (pp. 466-468; Figs. 12.29-12.30) 1. The spinal cord extends from the foramen magnum of the skull to the level of the first or second lumbar vertebra. It provides a bi-directional conduction path to and from the brain and serves as an important reflex center. 2. Fibrous extensions of the pia mater anchor the spinal cord to the spine and coccyx and prevent excessive spinal cord movement. 3. The spinal cord has 31 pairs of spinal nerves that run along its length and define the segments of the spinal cord. Copyright © 2010 Pearson Education, Inc.

145

146

4. There are cervical and lumbar augmentations for the nerves supplying the extremities and a series of nerve roots (cauda equina) running through the spine to its intervertebral foramina. C. Transverse Anatomy (pp. 468-476; Figs. 12.31-12.35; Boxes 12.2-12.3) 1. Two grooves partially divide the spinal cord into two halves: the anterior and posterior medial fissures. 2. Two arms that extend backwards are dorsal horns and the two arms that extend forward are abdominal horns. 3. In the thoracic and upper lumbar regions there are also pairs of lateral horns that extend laterally between the dorsal and abdominal horns. 4. Afferent fibers from peripheral receptors form the dorsal roots of the spinal cord. 5. The white matter of the spinal cord allows communication between the spinal cord and the brain. 6. All major spinal cords are part of paired multi-neuron cords, mostly crossing back and forth, consisting of a chain of two or three neurons, and exhibiting somatotropy. 7. Ascending pathways carry sensory impulses up through a chain of three neurons. a. Nonspecific ascending pathways receive information from many different types of sensory receptors and create multiple synapses in the brain. B. Specific ascending pathways carry accurate information from only one type of sensory receptor. C. The spinocerebellar tracts transmit information to the cerebellum about the stretching of muscles and tendons. 8. Two neurons are involved in the descending pathways: the upper motor neurons and the lower motor neurons. a. The direct or pyramidal system regulates fast, finely controlled or skillful movements. B. The indirect or extrapyramidal system regulates the muscles that maintain posture and balance, control the gross movements of the extremities, and the movements of the head, neck, and eyes involved in tracking visual objects. D. Spinal Cord Trauma and Disorders (pp. 476-477) 1. Any localized injury to the spinal cord or its roots causes paralysis (loss of motor function) or paraesthesia (loss of sensory function). 2. Polio results from the destruction of anterior horn neurons by the poliovirus. 3. Amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease, is a neuromuscular disease involving progressive destruction of anterior horn motor neurons and pyramidal tract fibers.

V. Diagnostic Techniques for Evaluating CNS Dysfunction (p. 477) A. Pneumoencephalography is used to diagnose hydrocephalus and provides X-ray visualization of the cerebral ventricles. B. A cerebral angiogram is used to assess the condition of the cerebral arteries leading to the brain in people who have had a stroke or TIA. C. Computed tomography and magnetic resonance imaging techniques allow visualization of most tumors, intracranial lesions, multiple sclerosis plaques, and areas of dead brain tissue. D. PET scans can locate brain lesions that trigger seizures and diagnose Alzheimer's disease. Copyright © 2010 Pearson Education, Inc.

Chapter 12

the central nervous system

SEEN. Aspects of Central Nervous System Development (pp. 477-478; Fig. 12.36) A. The brain and spinal cord grow and mature during the prenatal period under the influence of various organizational centers (p. 477). B. Sex-specific areas of the brain and spinal cord develop in response to the presence or absence of testosterone (p. 477). C. Oxygen starvation of the developing fetus can lead to cerebral palsy, a neuromuscular deficiency in which voluntary muscles become poorly controlled or paralyzed as a result of brain damage (p. 477). D. Old age brings some cognitive decline, but the losses are not significant until the seventh decade (p. 478).

Cross-references For more information on the topics covered in Chapter 12, see the chapters listed below. 1. Chapter 13: Function of the spinal nerves and the peripheral nervous system; the relationship between the peripheral nervous system and the gray and white matter of the spinal cord; different areas of the brain and neural integration 2. Chapter 14: Function of the spinal nerves and the peripheral nervous system; the relationship between the peripheral nervous system and the gray and white matter of the spinal cord 3. Chapter 15: Role of the Thalamus in the Special Senses; role of the cerebral cortex and cerebellum in the integration of sensory information 4. Chapter 16: Hypothalamus and hormone production 5. Chapter 18: Role of the medulla in regulation of heart rate 6. Chapter 19: Brain capillaries (barrier hematoencephalic); medulla and regulation of the diameter of blood vessels (vasomotor center); Hypothalamus and regulation of blood pressure 7. Chapter 22: Respiratory centers in medulla oblongata and pons; cortical and hypothalamic involvement in respiration 8. Chapter 23: Central nervous system involvement in reflex activity that controls digestive processes 9. Chapter 24: Role of the hypothalamus in regulating body temperature 10. Chapter 26: Role of the hypothalamus in fluid regulation and electrolyte balance 11 Chapter 27: Testosterone and Brain Development

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 19: General anatomy of the brain and cranial nerves Exercise 20: Electroencephalography Exercise 21: Spinal cord, spinal nerves and autonomic nervous system 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 19: General anatomy of the brain and cranial nerves. Exercise 20: Electroencephalography. Exercise 21: Spinal cord, spinal nerves and autonomic nervous system

Copyright © 2010 Pearson Education, Inc.

147

148

Text and media guide to human anatomy and physiology

Teaching Tips 1. Studying the central nervous system is difficult for most students. The complexity of the material can overwhelm anyone. Present the material from a general conceptual perspective and move on to a higher level of detail. This way, students are less likely to get lost. 2. When discussing the ventricles, draw a rough diagram on the chalkboard (or on the blanket) that shows a schematic representation of the chambers and connecting ducts. As students understand the serial nature of CSF flow, translate sketches into actual cross-sectional photos or accurate diagrams. 3. Students often have difficulty understanding how the cerebellum is involved in controlling motor activity. Try using a physical activity like golf to illustrate cerebellar interaction. For example, we all know how to swing a racquet, but only a well-developed cerebellar coordination of the action of muscle groups allows a "pro" to place the ball exactly where it should be. 4. Emphasize that the meningeal protection of the brain and spinal cord is continuous, but that the spinal cord has an epidural space while the brain does not.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Design or assemble microslides to demonstrate the cross-sectional anatomy of the spinal cord at several different levels to show how the gray and white matter changes with each level of the spinal cord. 3. Obtain a three-dimensional model of a human brain and compare it to a real human brain and/or a stuffed sheep brain. 4. Acquire a 3D model of a spinal cord, longitudinal and transverse, to illustrate its features. 5. Obtain stained sections of brain tissue to illustrate the differences between gray and white matter and show the inner parts. 6. Use a three-dimensional model or cast of the ventricles of the brain. 7. Obtain a sheep brain with the skull and/or meninges still intact.

Critical Thinking/Discussion Points 1. Discuss the difference between encephalitis and meningitis. 2. Prefrontal lobotomies have been used in psychotherapy in conjunction with electric shocks. How and why were these techniques used? 3. Given that the left hemisphere of a right-handed person seems to dominate brain functions, what could be done to increase left hemisphere use? 4. Anencephalic children often die soon after birth. Currently, there is a desire among some medical groups to use the organs of these children to help others. What are the advantages and disadvantages of this type of organ transplant? 5. If a needle is used to administer or withdraw fluid from the spaces around the spinal cord, where is the best place (along the spinal cord) to perform the procedure? There? 6. Follow the entire course of CSF from formation to absorption and examine the consequences if choroid plexus function is compromised or if an obstruction develops in the CSF outflow pathway.

Copyright © 2010 Pearson Education, Inc.

Chapter 12

the central nervous system

Library Research Topics 1. What techniques are currently used to locate and treat brain tumors? 2. How has the size and shape of the human brain changed over millions of years of evolution? Explore the development of the human nervous system. 3. What drugs are used to improve memory? Where and how do you work? 4. The sensory and motor areas of the cerebral cortex around the precentral and postcentral gyrus have been carefully mapped. How was it made? 5. Which experimental methods were used to study the limbic system? What research has been done to determine if some habitual criminals have flaws in this system? 6. Describe the latest techniques for studying CNS structure/function. 7. How can fetal tissue be used to repair CNS disorders in adults?

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all of the chapter-specific online media resources for Chapter 12 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 12.1 The Brain (pp. 430-453) Art Label: Lobes and Fissures of the Cerebral Hemispheres (Fig. 12.6a, p. 434) Art Label: Functional and Structural Areas of the Cerebral Cortex (Fig. 12.8a, p. 434) . 436) ) Artist Caption: Nuclear Base (Fig. 12.11, p. 442) Artist Caption: Mid-Sagittal Section of Brain, Part 1 (Fig. 12.12, p. 443) Artist Caption: Mid-Sagittal Section of Brain, Part 2 (Fig. 12.12, p. 443) Artistic Caption: Selected structures of the diencephalon (Fig. 12.13, p. 444) Artist Caption: Anterior and left lateral views of the brainstem and diencephalon (Fig. 12.15a-b, p. 446) Artist Annotated: Posterior view of the diencephalon, brainstem and diencephalon (Fig. 12.15c, p. 447) Artist's caption: Cross-section through various regions of the brainstem, midbrain (Fig. 12.16a, p. 448) Artist's caption: Cross-section through various regions of the brainstem, pons (Fig. 12.16b, p. 448) Artist's caption : Cross-section through different regions of the brainstem, medulla oblongata (Fig. 12.16c, p. 448) Memory game: structures of the brain Section 12.2 Higher mental functions (pp. 453-460) Section tt 12.3 Protection of the brain (p. 460–466) Artist Identification: Meninges: dura, arachnoid and pia mater (Fig. 12.24), page 460) Copyright © 2010 Pearson Education, Inc.

149

150

Text and media Teacher's guide to human anatomy and physiology Art caption: CSF location and circulation (Fig. 12.26a, p. 462) Case study: Stroke Case study: Parkinson's disease Section 12.4 The spinal cord (pp. 466-477) MP3 Tutor Session: Artistic Labeling of Sensory and Motor Pathways: Spinal Cord Anatomy (Figs. 12.31a–b, p. 469) Memory Game: Major Nerves of the Central Nervous System Case Study: Nervous System Section 12.5 Diagnostic Procedures for Evaluating CNS Dysfunction (p. 477) Section 12.6 Developmental Aspects of the Central Nervous System (pp. 477–478) Chapter Summary Crossword 12.1 Crossword 12.2 Crossword 12.3 Web Link Tests Type Tagging Test Chapter Matching Test Multiple Choice Test True or False Test Chapter Exercise Test Study Tools Histology Atlas myeBook Flashcards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1. What is Addiction? (ESF; 20 mins, 2006). This show accompanies Dr. Nora Volkow, director of the National Institute on Substance Abuse, during her informal group therapy with addicts and their families. Volkow uses brain imaging to illustrate the neurological effects of drugs and alcohol. Some content may be offensive. 2. Anatomy of the Human Brain (FHS; 35 min, 1997). neuropathologist dr. Marco Rossi dissects and examines a normal human brain. 3. Health News and Interviews: Video Clips on Mental Health and the Human Mind (FHS; 51 min., 2007). This collection of 34 video clips takes a close look at mental health and the human spirit. Aspects of chronic stress, sleep disorders, seasonality

Copyright © 2010 Pearson Education, Inc.

Chapter 12

4.

5.

6.

7.

8.

9.

10. 11.

12

the central nervous system

Mood disorders, depression, panic attacks, post-traumatic stress disorder and schizophrenia are covered, along with insights into brain architecture and the psychological benefits of exercise, meditation and pet ownership. The human brain in situ (FHS; 19 min, 1997). Neurobiologist Susan Standring conducts a basic anatomical study of the human brain and its connections in the skull. Standring identifies parts of the brain and skull. The human nervous system: the brain and cranial nerve videotape (BC; 28 min., 1997). This video by Rose Leigh Vines and Rosalee Carter of California State University, Sacramento lists the structures and functions of the nervous system. The Human Nervous System: Videotape of the Spinal Cord and Nerves (BC; 29 min, 1997). Illustrations and figures help students learn the organization of the spinal nerves into intricate plexuses. The major nerves that arise from these plexuses are traced in the cadaver as they pass through the upper and lower extremities. Men, Women and the Brain (FHS; 57 minutes, 1998). Experts from the National Institute for Child Health and Human Development and other institutions define and study the differences between the male and female brain. These differences can affect aging, literacy, spatial abilities, aggression, depression, schizophrenia, and sexuality. Mind/Brain/Machine: Connections between Disciplines (FHS; 52 min., 2007). This program involves physicians and scientists working with human, animal, or artificial brains to understand emotion, anatomical movement, and decision making. Experiments and case studies include the treatment of a young man born without a corpus callosum; fruit fly research at Caltech that could provide insight into the human brain and nervous system; fMRI tests that measure the brain's involvement in moral and ethical decisions; and NASA's development of the A.T.H.L.E.T.E. Robot. Examples of pathology in the human brain (FHS; 24 min, 1997). The neuropathologist Dr. Marco Rossi examines various human brain samples and presents evidence of trauma or disease. The Seven Ages of the Brain (FHS; 58 min, 1994). This program focuses on how a brain grows from a fertilized egg and how our brains change with age. Spinal Surgery (FHS; 46 min, 2001). Specialists from the University of Washington Harborview Medical Center are helping a man with multiple spinal fractures, a woman who needs a bone graft after her neck was fractured in a car accident, a man who needs a spinal disc surgery to relieve chronic pain, and a 76-year-old patient. old woman nearly paralyzed by spinal stenosis. The following program contains scenes that may offend your moral sense. Stress, Trauma, and the Brain (FHS; 57 minutes, 1999). In the first segment of this program, physicians from Harvard Medical School and elsewhere examine the stresses of modern life in light of the innate fight-or-flight mechanism. In section two, a pioneer in brain imaging technology and MIT experts describe imaging techniques and their application in brain tumor surgery. In the third section, doctors examine a brain trauma.

Software 1. 2. 3. 4.

A.D.A.M.® Interactive Anatomy® 4.0 (see page 9 of this manual for a complete list). A.D.A.M.® MediaPro (see page 9 of this manual for a complete list). A.D.A.M.® Anatomy Practice (see page 87 of this manual for a complete list). Interactive Nervous System (IM; Windows). This 2-disc CD-ROM set examines the structure, functions, and processes of the nervous system. Study the response to stimuli, neurons, reflexes and senses.

Copyright © 2010 Pearson Education, Inc.

151

152

Text and Media Human Anatomy & Physiology Instructor Manual 5th Activity Anatomy Lab™ 2.0: Human cadaver, anatomy models, cat (see page 9 of this manual for a complete list). 6. The Ultimate Human Body, version 2.2 (see page 9 of this manual for a complete list).

Material to improve the lesson Thumbnails of all illustrations in Chapter 12 can be found in Appendix B.

Index Instructor Slide/Resource DVD Image Image Image Image Image Image Image

12,1 12,2 12,3 12,4 12,5 12,6 12,7 12,8 12,9

Figure 12.10 Figure 12.11 Figure 12.12 Figure 12.13 Figure 12.14 Figure Figure Figure Figure Figure

12,15 12,16 12,17 12,18 12,19

Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure

12,20 12,21 12,22 12,23 12,24 12,25 12,26 12,27 12,28 12,29 12,30 12,31 12,32 12,33

Figure 12.34

Development of the neural tube from the embryonic ectoderm. Embryonic development of the human brain. Effect of spatial confinement on brain development. CNS gray and white matter pattern (oversimplified). cerebral ventricles. Lobes and fissures of the cerebral hemispheres. Functional imaging (fMRI) of the cerebral cortex. Functional and structural areas of the cerebral cortex. Body maps in the primary motor cortex and the somatosensory cortex of the brain. Types of fibrous pathways in white matter. Basic Cores. Mid-sagittal section of the brain showing the diencephalon (purple) and the brainstem (green). Selected structures of the diencephalon. Inferior view of the brain showing the three parts of the brainstem: midbrain, pons and medulla oblongata. Three views of the brainstem (green) and diencephalon (purple). Cross-sections through different regions of the brainstem. cerebellum. The limbic system. The reticular formation. Electroencephalography and brainwaves. Types and stages of sleep. memory processing. Proposed memory circuits. Meninges: dura mater, arachnoid and pia mater. dural septa and dural sinuses. Formation, location and circulation of the CSF. Hydrocephalus in a newborn. Structure of the embryonic spinal cord. Rough structure of the spinal cord, dorsal view. Schematic representation of a lumbar puncture. Anatomy of the spinal cord. Organization of the gray matter of the spinal cord. Main ascending (sensory) and descending (motor) pathways of the spinal cord, cross-sectional view. Selected tracts of the ascending tract of the spinal cord.

Copyright © 2010 Pearson Education, Inc.

Chapter 12 Figure 12.35 Figure 12.36 Table 12.1 Table 12.2 Table 12.3

the central nervous system

Three descending pathways through which the brain influences movement. Newborn with lumbar myelomeningocele. Functions of the main regions of the brain Main and ascending (sensory) pathways of the spinal cord Main and descending (motor) pathways of the spinal cord

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 13. See Figure 12.2 for a diagram of the primary embryonic brain alveoli and resulting brain structure. 14. a. The gyri increase the cortical surface area, allowing more neurons to occupy the limited space. (p. 431) b. grooves and cracks; Rounds (p. 433) c. Central longitudinal tear (p. 433) d. central groove; lateral groove (p. 433) 15. a. See illustration. 12.8 for a drawing of the functional areas of the brain. B. The right hemisphere of the brain is involved in drawing for most people. The right hemisphere is involved in visual-spatial and creative activities. (p. 440) c. Primary Motor Cortex: All voluntary somatic motor responses emanate from this region. (p. 435) Premotor Cortex: This region controls learned motor skills of a repetitive or patterned nature. (p. 437) Somatosensory Association Area: Integrates and analyzes various somatosensory information such as temperature, touch, pressure and pain. (p. 437) Primary somatosensory cortex: receives all somatosensory information from receptors in the skin and from proprioceptors in the muscles; identifies the body region that is being stimulated. (p. 437) Field of View - Receives information coming from the retina of the eye. (p. 440) Auditory Zone – Receives information coming from the auditory receptors in the inner ear. (pp. 437 and 438) Prefrontal Cortex: Mainly concerned with thinking, intelligence, motivation and personality. It also combines experiences necessary for the production of abstract ideas, judgment, planning, and awareness, which is important for planning motor activity. (p. 439) Wernicke's area - area of ​​language involved in understanding language, especially when the word needs to be pronounced or used. (p. 457) Broca's area – Formerly called motor language area; now known to be active in many other activities as well. (p. 437) 16. a. Specialization of cortical functions. The “dominant” hemisphere is characterized by language and mathematical skills. The non-dominant hemisphere is better in visuospatial skills, intuition, emotion, and appreciation of art and music. (pp. 439-440) b. Both hemispheres communicate with each other perfectly and instantaneously, so there is tremendous integration; therefore neither side is better. However, each hemisphere has unique abilities that their partner does not share. (p. 440)

Copyright © 2010 Pearson Education, Inc.

153

154

Text and Media Teacher's Manual of Human Anatomy and Physiology 17. a. Start with slow and sustained movements; Help coordinate and control motor activity. (p. 441) b. Putamen and globus pallidus (p. 441) c. Caudate nucleus (p. 441) 18. Three bundles of paired fibers (cerebellar peduncles) connect it to the brainstem. (p. 450) 19. The cerebellum acts as an autopilot, initiating and coordinating the activity of skeletal muscle groups. (See page 450 for a step-by-step explanation.) 20. a. Medial aspect of each cerebral hemisphere. (p. 452) b. Cingulate gyrus, parahippocampal gyrus, hippocampus, hypothalamic regions, mammillary bodies, septal nuclei, amygdaloid nucleus, anterior thalamic nuclei, and fornix. (p. 452) c. It functions as our emotional or affective (feeling) brain. (p. 452) 21. a. It extends through the central nucleus of the medulla oblongata, the pons, and the midbrain. (pp. 452 and 453) b. RAS stands for Reticular Activating System, which is our cortical excitation mechanism. It helps keep the cerebral cortex alert while filtering out unimportant information. (pp. 452-453) 22. An aura is a sensory hallucination that occurs immediately before an attack, such as taste, smell, or flashes of light. (p. 454) 23. REM sleep accounts for about 50% of babies' total sleep time, but decreases with age and stabilizes at 25%. Stage 4 sleep steadily decreases from birth and disappears completely in people over 60 years of age. (pp. 455 and 456) 24. STM is a volatile memory that serves as a kind of temporary storage for data and is limited to seven or eight blocks of data. LTM seems to have unlimited storage capacity and is very durable if not changed. (p. 457) 25. Memory consolidation is the process of transferring memories from short-term memory to long-term memory, associating new facts with the various categories of knowledge already stored in the cerebral cortex. (p. 458) 26. Factual memory is the ability to learn explicit information and is related to our conscious thoughts and our ability to manipulate symbols and language. Ability memory is related to motor activities acquired through practice. (p. 458) 27. The CNS is protected by: cranial bones, meninges, liquor and blood-brain barrier. (p. 461) 28. a. CSF is formed in the choroid plexus by a secretory process involving active transport and diffusion and is eliminated through the arachnoid membrane. See illustration. 12:25 p.m. for the circuit. (p. 463) b. A condition called hydrocephalus can develop. In children, the fontanelles allow for expansion without brain damage, but in adults, the inability to expand the skull due to brain compression can result in severe damage. (p. 463) 29. The blood-brain barrier consists mainly of capillaries with endothelial cells held together by tight junctions. This property makes them highly selective, ensuring that only certain substances gain access to nerve tissue. (pp. 463 and 464) 30. Scalp, cranial bones, periosteal layers of dura mater, subdural space, arachnoid membrane, subarachnoid space, pia mater, brain tissue. (pp. 461-463) 31. a. A concussion occurs when the brain injury is mild and the symptoms are mild and transient. Contusion occurs when there is significant tissue destruction. (p. 468) b. Due to a RAS lesion. (p. 464) 32. The spinal cord is contained within the vertebral column and extends from the foramen magnum of the skull to the first or second lumbar vertebra below the ribs. That's it

Copyright © 2010 Pearson Education, Inc.

Chapter 12

the central nervous system

composed of gray and white matter. The gray matter consists of a mixture of the cell bodies of neurons, their myelinated processes, and neuroglia. In cross section, it looks like a butterfly. The white matter consists of myelinated and unmyelinated nerve fibers that run in three directions: ascending, descending, and transverse. The ascending and descending pathways make up most of the white matter. There are two types of spinal cord roots: ventral and dorsal, and they fuse laterally to form the spinal nerves, which are part of the peripheral nervous system. (pp. 468-470) 33. The direct pathway regulates rapid and subtle movements (skills), while the indirect pathways regulate the muscles responsible for maintaining balance, muscles involved in general movement of the extremities, and the muscles of the head. neck and legs. Eyes involved in tracking objects in the visual field. (pp. 473 and 474) 34. a. The lateral spinothalamic tract transmits pain, temperature, and touch impulses, which are ultimately interpreted in the somatosensory cortex. When clipped, our sensory perception of the occurrence of a stimulus, as well as our ability to recognize the strength of the stimulus and the location or pattern of the stimulus, or its specific texture, shape, or quality, e.g. B. sweet, to identify or bitter, would be damaged. (pp. 473 and 474) b. The anterior and posterior spinocerebellar pathways carry information from proprioceptors (muscles or tendons that stretch) to the cerebellum, which uses this information to coordinate skeletal muscle activity. Cerebellar damage can cause balance problems and speech difficulties. (pp. 473 and 474) c. The tectospinal tract transmits motor impulses from the midbrain that are important for the coordinated movement of the head and eyes toward visual targets. If cut, problems with locomotion may arise. (pp. 473-474) 35. Spasticity: due to damage to the upper motor neurons of the primary motor cortex. Muscles can respond to reflex arcs elicited at the level of the spinal cord. (p. 476) Flaccid Paralysis - Damage to the ventral root or anterior horn cells. The muscles do not react because they are not receiving any stimuli. (p. 476) 36. Paraplegia: damage to the spinal cord (lower motor neurons) between T1 and L1, resulting in paralysis of both lower extremities. (p. 476) Hemiplegia - Damage, usually to the brain, causing paralysis on one side of the body. (p. 476) Quadriplegia - Spinal cord damage in the neck area affecting all four limbs. (p. 476) 37. a. A stroke, also known as a stroke, occurs when blood flow to an area of ​​the brain is blocked and vital brain tissue dies. A new hypothesis points to the release of glutamate by oxygen-depleted neurons (and subsequent entry of excess Ca2) as the culprit. (pp. 464 and 465) b. Any event that kills brain tissue from lack of oxygen; includes blockage of a cerebral artery by a blood clot, compression of brain tissue by hemorrhage or edema, and atherosclerosis. The consequences are paralysis, sensory deficits, speech difficulties and language problems. (pp. 464 and 465) 38. a. The continuous myelination of nerve tissue is responsible for the growth and maturation of the nervous system. B. With age, the weight and volume of the brain decreases. (pages 477 and 478)

Critical Thinking Problems and Clinical Application 1. a. The only likely diagnosis is hydrocephalus. (p. 463) b. CT or ultrasound, but especially pneumoencephalography. (p. 477)

Copyright © 2010 Pearson Education, Inc.

155

156

Text and media guide to human anatomy and physiology

2. 3. 4.

5.

6.

7.

8.

C. The lateral and third ventricles are enlarged; the fourth ventricle, central canal, and subarachnoid space are unaffected. When the arachnoids become obstructed, all areas of CSF become enlarged. (p. 463) Alzheimer's disease. (p. 465) Probably the frontal lobes, particularly the prefrontal cortex, which mediates personality and moral behavior. (p. 439) In myelomeningocele, a cyst protrudes from the spine that contains parts of the spinal cord, nerve roots, and meninges. The pressure during vaginal delivery can cause the cyst to rupture, leading to infection and further damage. A cesarean section is preferable. (p. 478) Parkinson's disease. B. Neurons of the substantia nigra; Dopamine neurotransmitter deficiency. C. Combined drug therapy with L-Dopa, carbidopa and a dopamine agonist. (pp. 465-466) Cynthia's palsy from the waist down is the result of damage to specific and non-specific ascending pathways, resulting in loss of sensory information to the brain from the extremities and damage to the upper motor neurons, but not the lower ones, the descending ways. . All of this leads to the loss of voluntary control of muscle movements, but leaves reflex movements intact. So pressure sores would be a problem as Cynthia will be immobilized for a long time and unable to feel the localized compressions they cause. As a result of voluntary sensory and motor loss, she is prone to bladder infections and infrequent, incomplete urination due to her inability to sense when her bladder is full, which can cause her to overfill. Muscle spasms result from reflex contractions elicited by lower motor neurons that are still intact. (p. 476) The left hemisphere of the brain was affected. The specific area of ​​the brain affected was Broca's area. Broca's area is usually located on the left side of the brain and controls thinking, language readiness, and the muscles involved in speech. (p. 437) The needle is inserted below L2 in the lumbar spine. The needle is inserted into the subarachnoid space to drain CSF and test for the presence of pathogens. (p. 468)

Recommended Reading Birmingham, Karen. "The Future of Neuroprotective Drugs in Doubt". Nature Medicine 8(1) (January 2002): 5. Bower, B. "The brain can forge some memories in waves." Science News 160(19) (November 2001): 294. Bucciantini, Monica, et al. "The inherent toxicity of aggregates implies a common mechanism for protein misfolding diseases." Nature 416 (6880) (April 2002): 507–511. Calder, AJ, et al. "Neuropsychology of fear and aversion". Nature Reviews: Neuroscience 2 (5) (May 2001): 352-363. Check it out Erika. "Parkinson's patients show a positive response to implants." Nature 416 (6882) (2002 Apr): 666. Dunnett, S.B., et al. "Cell Therapy in Parkinson's – Stop or Go?" Nature Reviews: Neuroscience 2 (5) (May 2001): 365-368. Eichenbaum, Howard. "A cortical-hippocampal system for declarative memory". Nature Reviews: Neuroscience 1(1) (October 2000): 41-50. Fricker-Gater, Rosemary A. and Stephen B. Dunnett. "Rewiring the Parkinson's Brain". Nature Medicine 8(2) (February 2002): 105-106. Copyright © 2010 Pearson Education, Inc.

Chapter 12

the central nervous system

Gross, Charles G. "Neurogenesis in the Adult Brain: Death of a Dogma." Nature Reviews: Neuroscience 1(1) (October 2000): 67-72. Hansel, DE, et al. "Neuropeptide Y functions as a neuroproliferative factor." Nature 410 (6831) (April 2001): 940–944. Helmut, Laura. "Redesigning the brain map of the body". Science 296 (5573) (May 2002): 1587–1588. Macklis, Jeffrey D. "New Memories from New Neurons." Nature 410 (6826) (March 2001): 314-315. Manabe, Toshiya. "Does BDNF have presynaptic or postsynaptic targets?" Science 295 (5560) (March 2002): 1651–1652. MAQUET, Pierre. "The role of sleep in learning and memory". Science 294 (5544) (November 2001): 1048-1051. MARX, John. "New clues to the 'how' of Alzheimer's disease". Science 293 (5538) (2001 Sep): 2192-2194. Miller, Earl K. "The Prefrontal Cortex and Cognitive Control." Nature Reviews: Neuroscience 1(1) (October 2000): 59-65. Nathanson, Neal, and Paul Fine. "Polio eradication: a dangerous end". Science 296 (April 2002): 269–270. Saey, T.H. "Fruit flies need an adequate dose of dopamine to learn without sleep." Science News 174(5) (August 2008): 8. Shi, Song-Hai. "AMPA receptor dynamics and synaptic plasticity". Science 294 (5548) (November 2001): 1851–1852. Siegel, Jerome M. "The Memory Consolidation Hypothesis of REM Sleep." Science 294 (5544) (November 2001): 1058-1063. Star, Claudius. "Initial patterns of the central nervous system: how many organizers?" Nature Reviews: Neuroscience 2(2) (February 2001): 92–98. Stickgold, R., and J. M. Ellenbogen. "Easy! The sleeping brain in action. Scientific American Mind 19 (4) (2008 Aug/Sept): 23-30. Svitil, Kathy A. "Brain Fire: Programmable Implants Can Help Epileptics Detect Seizure Onset?" Discover 23 (5) (May 2002) Young, E. "Sleep Tight." New Scientist 197 (2647) (March 2008) : 30–34 Zimmer, C. "The Brain: Feel Like You're Racing against the Clock?" Discover 29(8) (August 2008): 21–23.

Copyright © 2010 Pearson Education, Inc.

157

13

The peripheral nervous system and reflex activity.

Objectives 1. Define the peripheral nervous system and list its components.

11. Define plexus. Name the main plexuses and describe the distribution and function of the peripheral nerves radiating from each plexus.

PART 1: SENSORY RECEPTORS AND SENSATION

PART 3: ENGINE END AND ENGINE ACTIVITY

sensory receptors

peripheral motor endings

2. Classify common sensory receptors by structure, stimulus recognized, and body location. Sensory Integration: From Sensation to Perception 3. Describe the events that lead to sensation and perception. 4. Describe receptor and generator potentials and sensory adaptation. 5. Describe the main aspects of sensory perception.

PART 2: TRANSMISSION CIRCUITS: NERVES AND THEIR STRUCTURE AND REPAIR Nerves and associated ganglia 6. Define ganglia and give the general location of ganglia in the body. 7. Describe the general structure of a nerve. 8. Follow the process of nerve regeneration. Cranial nerves 9. Name the 12 pairs of cranial nerves; indicate the body region and the structures innervated by it. spinal nerves

12. Compare and contrast the motor endings of somatic and autonomic nerve fibers. Motor integration: from intention to effect 13. Describe the three levels of the motor hierarchy. 14. Compare the roles of the cerebellum and basal ganglia in controlling motor activity. PART 4: REFLEX ACTIVITY The reflex arc 15. Name the components of a reflex arc and distinguish between autonomic and somatic reflexes. Spinal Reflexes 16. Compare and contrast the extension, flexion, sacrum extensor, and Golgi tendon reflexes. Developmental Aspects of the Peripheral Nervous System 17. Describe the developmental relationship between the segmented arrangement of peripheral nerves, skeletal muscles and skin dermatomes. 18. List the changes that occur in the peripheral nervous system with age.

10. Describe the origin of a spinal nerve and the general distribution of its branches.

158 Copyright © 2010 Pearson Education, Inc.

Chapter 13

The peripheral nervous system and reflex activity.

159

Suggested Lesson Plan PART 1: SENSORY RECEPTORS AND SENSATION I. Sensory Receptors (pp. 485-488; Fig. 13.1; Table 13.1) A. Sensory receptors are specialized in responding to changes in their environment called stimuli (pp. 485 , Fig. 13.1). B. Receptors can be classified by the type of stimulus and include mechanoreceptors, thermoreceptors, photoreceptors, chemoreceptors, and nociceptors (p. 485). C. Receptors can be classified according to their location or the location of the stimulus and include exteroceptors, interoceptors and proprioceptors (p. 486). D. Receptors can be classified based on their structural complexity and can be simple or complex (p. 486). E. Simple receptors are general senses and can be unencapsulated or encapsulated dendritic terminals (pp. 486-488; Table 13.1). 1. Unencapsulated dendritic endings are free or bare nerve endings and sense temperature, pain, itch, or light touch. 2. Encapsulated dendritic tails consist of a dendrite encased in a connective tissue capsule and detect discriminatory touch, initial, continuous, deep pressure and stretch of muscles, tendons and joint capsules.

II. Sensory Integration: From Sensation to Perception (pp. 488-491; Fig. 13.2) A. The somatosensory system, the part of the sensory system that serves the body wall and extremities, comprises the receptor level, the sensory level of circuitry and the level of perception (pp. 488-491; Fig. 13.2). 1. Processing at the receptor level involves a stimulus that must excite a receptor for the sensation to occur. 2. Circuit level processing is involved in delivering impulses to the appropriate region of the cerebral cortex for localization and perception of the stimulus. 3. Perceptual level processing involves the interpretation of sensory input to the cerebral cortex. 4. Pain perception protects the body from damage and is stimulated by extremes of pressure and temperature, and by chemicals released from damaged tissue.

PART 2: TRANSMISSION CIRCUITS: NERVES AND THEIR STRUCTURE AND REPAIR III. Nerves and Associated Ganglia (pp. 491-492; Figs. 13.3-13.4) A. A nerve is a cord-like organ composed of parallel bundles of peripheral axons surrounded by fibrous sheaths (p. 491; Fig. 13.3 ). B. Ganglia are collections of neuronal cell bodies associated with nerves in the PNS (p. 491). C. If a neuron in the axon is damaged and the cell body remains intact, severed or compressed axons can regenerate (pp. 491-492; Fig. 13.4).

4. Cranial nerves (pp. 493-501; Fig. 13.5; Table 13.2) A. There are twelve pairs of cranial nerves that originate in the brain (pp. 493-501; Fig. 13.5; Table 13.2).

159 Copyright © 2010 Pearson Education, Inc.

160

Text and Media Human Anatomy and Physiology Teacher's Guide 1. The olfactory nerves (cranial nerve I) perceive smells. 2. The optic nerves (cranial nerve II) are responsible for seeing. 3. Oculomotor, trochlear, and oculomotor nerves (cranial nerves III, IV, and VI) allow movement of the eyeball. 4. The trigeminal nerves (cranial nerve V) provide facial sensation and motor control of the muscles of mastication. 5. The facial nerves (cranial nerve VII) allow movement of the muscles that produce facial expression. 6. The vestibulocochlear nerves (VIIIth cranial nerve) are responsible for hearing and balance. 7. The glossopharyngeal nerves (cranial nerve IX) control the tongue and pharynx. 8. The vagus nerves (cranial nerve X) control various visceral organs. 9. The accessory nerves (cranial nerve XI) are related to the vagus nerves. 10. The hypoglossal nerves (cranial nerve XII) innervate the tongue muscles.

V. Spinal nerves (pp. 501-511; figs. 13.6-13.12; boxes 13.3-13.6) A. Thirty-one pairs of mixed spinal nerves arise from the spinal cord and supply the entire body except the head and neck (p. 502, figs. 13.6-13.7 ). 1. Each spinal nerve is connected to the spinal cord by a dorsal root and an abdominal root. B. Innervation of certain body regions (pp. 502-511; Figs. 13.8-13.12; Boxes 13.3-13.6) 1. Branches are distal and are tributaries of spinal nerves which carry motor and sensory fibers. 2. The back is innervated by the dorsal branches, each branch innervating the muscle aligned with the spinal origin point. 3. In the thorax only, the ventral branches are arranged in a simple segmental pattern, analogous to that of the dorsal branches. 4. The cervical plexus is formed by the ventral branches of the first four cervical nerves. 5. The brachial plexus is located partly in the neck and partly in the axilla and arises from virtually all nerves innervating the upper extremity. 6. The sacral and lumbar plexuses overlap, and since many fibers of the lumbar plexus contribute to the sacral plexus via the lumbosacral trunk, the two plexuses are often referred to as the lumbosacral plexus. 7. The area of ​​skin supplied by the cutaneous branches of a single spinal nerve is called the dermatome. 8. Hinton's Law states that any nerve supplying a muscle that produces motion in a joint also supplies the joint and overlying skin.

PART 3: ENGINE END AND ENGINE ACTIVITY VI. Peripheral motor endings (p. 512) A. Peripheral motor endings are the element of the PNS that activates effectors by releasing neurotransmitters (p. 512). B. Somatic motor fiber endings that innervate voluntary muscles form elaborate neuromuscular junctions with their effector cells and release the neurotransmitter acetylcholine (p. 512).

Copyright © 2010 Pearson Education, Inc.

Chapter 13

The peripheral nervous system and reflex activity.

C. Connections between autonomic motor terminals and visceral effectors surround the varices and release acetylcholine or epinephrine as their neurotransmitter (p. 512).

VIII. Motor Integration: Intention to Effect (pp. 512-513; Fig. 13.13) A. Levels of Motor Control (pp. 512-513; Fig. 13.13) 1. The segmental level is the lowest level in the motor control hierarchy and is formed by the circuits of the spinal cord. 2. The plane of projection has direct control over the spinal cord. 3. The precommand level consists of the cerebellum and basal ganglia and is the highest level of the motor system hierarchy.

PART 4: REFLEX ACTIVITY VIII. The Reflex Arc (p. 514; Fig. 13.14) A. Reflexes are rapid, predictable, unlearned motor responses to a stimulus and occur in very specific neural pathways called reflex arcs (p. 514 ; Fig. 13.14).

IX. Spinal reflexes (pp. 514-520; Figs. 13.15-13.19) A. Spinal reflexes are somatic reflexes mediated by the spinal cord (pp. 514-520; Figs. 13.15-13.19). 1. During the stretch reflex, the muscle spindle lengthens and is stimulated by external or internal stretching. 2. The Golgi tendon reflex produces muscle relaxation and lengthening in response to contraction. 3. The flexion or withdrawal reflex is triggered by a painful stimulus and causes automatic withdrawal from the body part threatened by the stimulus. 4. The crossed extension reflex is a complex spinal reflex consisting of an ipsilateral withdrawal reflex and a contralateral extension reflex. 5. Superficial reflexes are triggered by gentle stimulation of the skin.

X. Developmental Aspects of the Peripheral Nervous System (p. 520) A. Spinal nerves branch off from the developing spinal cord and adjacent neural crest and exit between the developing vertebrae. Each nerve is connected to the adjacent muscle mass (p. 520). B. The cranial nerves innervate the muscles of the head in a similar manner (p. 520). C. Sensory receptors atrophy to some degree with age and there is decreased muscle tone in the face and neck; Reflections occur a little slower (p. 520).

Cross-references For more information on the topics discussed in Chapter 13, see the chapters listed below. 1st 2nd 3rd 4th 5th

Chapter 3: Membrane Functions Chapter 4: Nervous Tissue Chapter 5: Skin Sensation and Sensory Receptors Chapter 9: Neuromuscular Connection Chapter 11: Membrane Potentials; neural integration; serial and parallel processing; synapse; Neurotransmitters Copyright © 2010 Pearson Education, Inc.

161

162

Text and media Teacher's manual of human anatomy and physiology 6. Chapter 12: Ascending and descending pathways of the spinal cord; spinal roots; spinal cord gray and white matter 7. Chapter 15: Sensory Receptors for the Special Senses and Generative Potentials; cranial nerves, which connect to your special senses; Reflex Actions of the Special Senses 8. Chapter 23: Reflex Actions and Control of the Digestive Secretions; nerve plexuses involved in digestion; Role of the Vagus Nerve in Parasympathetic Control 9. Chapter 25: Control of the Spinal Voiding Reflex 10. Chapter 27: Spinal Reflexes and the Physiology of Sexual Response

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 22: Human Reflex Physiology 2. Marieb, E.N. & S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 22: Human Reflex Physiology

Teaching Tips 1. Emphasize the difference between the central and peripheral nervous systems, but emphasize that the nervous system functions as a continuous unit, although we like to study its anatomy in parts. Due to this approach, students often overlook the integration of all areas with each other. 2. Many students will have difficulty understanding the difference between receiving potentials, generating potentials, and action potentials. It's worth taking the time to make sure the distinction is clear. 3. When discussing nerve anatomy, emphasize the similarity between the basic structure of muscle tissue and nerve tissue. Also, make students aware of the similarity in nomenclature. Point out that if you know the structure of the muscle, you already know the anatomy of the nerve (with slight changes in names). 4. Students often have problems with neuron regeneration and myelination (ie, understanding why, since both CNS and PNS neurons are myelinated, regeneration occurs in the PNS and not the CNS). Spend some time explaining the difference, or refer the class to Chapter 11 to review myelination, the Schwann sheath, and oligodendrocytes. 5. Using a diagram or model of the spinal cord, describe the pathway of a spinal reflex. Emphasizes the origin of the reflex with a stimulus at sensory receptors, transmission in the spinal cord along sensory neurons passing through the dorsal root, integration of sensory input into the spinal cord, and then motor flow carried along the dorsal root to the effector organs. along the neurons in the ventral area of ​​the root. This approach not only allows students to see the flow of information through the spinal cord, but also helps them understand the subdivisions of the nervous system as integrated parts of a complete system. 6. Emphasize to students that the CNS receives sensory inputs from many sources simultaneously, all of which can be aggregated into a single specific motor output.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Choose a student to help illustrate reflexes such as the patellar, plantar, and abdominal reflexes.

Copyright © 2010 Pearson Education, Inc.

Chapter 13

The peripheral nervous system and reflex activity.

3. Obtain a skull to illustrate the location, exits and entrances of various cranial nerves such as B. the olfactory nerve, the optic nerve and the trigeminal nerve. 4. Obtain a sheep brain with intact cranial nerves to illustrate their location. 5. Use a 3D model of the peripheral nervous system to visualize the distribution of the spinal nerves. 6. Obtain a three-dimensional model of a cross-section of the spinal cord to illustrate the five components of a reflex arc and terms such as ipsilateral, contralateral, and monosynaptic.

Critical Thinking/Points for Discussion 1. How can novocaine be injected into an area of ​​the lower jaw to numb the entire side of the jaw and tongue? 2. How can seat belts for front and rear passengers in cars prevent serious neurological damage? How can using only lap belts cause serious harm? 3. Some over-anxious parents cradle their newborns in their hands. What harm can that do? 4. Pregnant women often experience numbness in their fingers and toes. There? 5. Animals act far more thoughtfully than humans. There? 6. Different types of spinal cord injuries result in different degrees of loss of function. Explain why paralyzed people may still have the ability to feel in affected areas. Also describe the differences in injuries that lead to spastic and flaccid paralysis.

Library Research Topics 1st 2nd 3rd 4th

How is acupuncture related to the distribution of the spinal nerves? Will all polio victims be paralyzed? What different forms are there? How was microsurgery used to reattach severed peripheral nerves? What techniques can be used to increase our reflective actions?

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all of the chapter-specific online media resources for Chapter 13 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives PART 1: SENSORY RECEPTORS AND SENSATION Section 13.1 Sensory Receptors (pp. 485-488) Section 13.2 Sensory Integration: From Sensation to Perception (pp. 488-491) PART 2: TRANSMISSION CIRCUITS: NERVES AND THEIR STRUCTURE AND REPAIR Section 13.3 Nerves and associated ganglia (pp. 491–492)

Copyright © 2010 Pearson Education, Inc.

163

164

Text and media Teacher's manual of human anatomy and physiology Section 13.4 Cranial nerves (pp. 493-501) Section 13.5 Spinal nerves (pp. 501-511) Memory game: nerves and related CNS structures PART 3: MOTOR END AND ACTIVITY MOTOR Section 13.6 Peripheral motor endings (p. 512) Case Study: Neuromuscular Dysfunction Section 13.7 Motor Integration: Effect Intention (pp. 512-513) PART 4: REFLECTIVE ACTIVITY Section 13.8 The Reflex Arc (p. 514) Animation A&P Flix: The Reflex Arc Memory Game: Reflex and Response Tracts Section 13.9 Spinal Reflexes (pp. 514-520) MP3 Tutor Session: Spinal Reflexes Case Study: Nervous System Section 13.10 Developmental Aspects of the Peripheral Nervous System (p. 520) Chapter Summary Crossword 13.1 Crossword 13.2 Web Links Chapter Tests Art Labeling Test Matching Test Multiple Choice Test Chapter Practice Test Title Practice Test Study Histology Atlas myeBook Flashcards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1. Reflexes and Conscious Movement (FHS; 28 min, 1993). This program examines the range of conscious and unconscious reflexive and controlled movements of the human body, shows how controlling nerve impulses arise and are carried out, traces actions such as walking and scratching from the nerve cell to the brain, and distinguishes will from habit and reflection.

Copyright © 2010 Pearson Education, Inc.

Chapter 13

The peripheral nervous system and reflex activity.

2. Spinal Cord Injury: Recovery of Function (FHS; 20 min, 1994). Provides an overview of spinal cord injury diagnosis for different treatment levels. Excellent for classroom discussions and presentations. 3. The spine: the body's central highway (FHS; 13 min, 2002). This edition of the Science Screen Report discusses the structure and function of the spinal cord, the impact of spinal cord damage on body movement, and medical advances in the treatment of spinal cord injuries.

A.D.A.M.® Interactive Anatomy® 4.0 software (see full list on page 9 of this manual). A.D.A.M.® MediaPro (see page 9 of this manual for a complete list). A.D.A.M.®Anatomy Practice (see page 87 of this manual for a complete list). Interactive Physiology® 10 System Suite: Nervous System I and II (see page 137 of this manual for a complete list). 5. Practice Anatomy Lab™ 2.0: Human Cadaver Anatomical Models (See page 9 of this guide for a complete list). 6. The Ultimate Human Body, version 2.2 (see page 9 of this manual for a complete list).

1. 2. 3. 4.

Materials to Improve Teaching Thumbnails of all the figures in Chapter 13 can be found in Appendix B.

Figure 13.1 Figure 13.3 Figure 13.4 Figure 13.5 Figure 13.7 Figure 13.7 Figure 13.9 Figure 13.10 Figure 13.11 Figure 13.13 Figure 13.14 Figure 13.15 Figure 13.18 Table 13.18 Table 13.18 3.3.3.3.3.3. 3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3. Table 13.4 Table 13.5 Table 13.6

Place of the PNS in the structural organization of the nervous system. Three basic levels of neural integration in sensory systems. structure of a nerve. Regeneration of a nerve fiber in a peripheral nerve. Location and function of the cranial nerves. spinal nerves. Formation of spinal nerves and distribution of branches. The cervical plexus. The brachial plexus. The Lumbar Plexus. The sacral plexus. dermatome map. engine control hierarchy. The five basic components of all reflex arcs. Anatomy of the muscle spindle and Golgi tendon organ. function of the muscle spindle. The stretch reflex The Golgi tendon reflex. The crossed stretch reflex. Common sensory receptors classified by structure and function Cranial nerves Branches of the cervical plexus (see Figure 13.8) Branches of the brachial plexus (see Figure 13.9) Branches of the lumbar plexus (see Figure 13.10) Branches of the sacral plexus (see Figure 13.11)

Copyright © 2010 Pearson Education, Inc.

165

166

Text and media guide to human anatomy and physiology

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Essay Questions with Short Answers 12. The SNP enables the SNC to obtain information and execute its decisions. (p. 485) 13. The PNS includes all neural tissues outside the CNS, ie sensory receptors, peripheral nerves (cranial or spinal), ganglia and motor nerve endings. Peripheral nerves transmit sensory and motor impulses, ganglia contain cell bodies of sensory or autonomic nerve fibers, sensory receptors receive stimuli, and motor endplates release neurotransmitters that regulate effector activity. (p. 485) 14. Sensation is simply the knowledge of a stimulus, while perception also includes the meaning of the stimulus. (p. 488) 15. a. Central pattern generators (CPGs) control locomotion and frequently recurring motor activities. B. The precommand center, cerebellum, and basal ganglia modify and control the activity of the CPG circuits. (p. 512) 16. See Figure 13.13. 17. The cerebellum integrates inputs from all ascending pathways before those inputs reach the cortical command centers. The basal ganglia play a role in inhibiting cortical areas of the brain and preventing the response until the inhibition stops. (p. 513) 18. In the PNS, macrophages and Schwann cells physically and chemically support the regeneration process. Macrophages do not support the process in the CNS. In addition, the oligodendrocytes die and therefore do not help in fiber regeneration. (pp. 491 and 492) 19. a. Spinal nerves are formed from dorsal and ventral roots attached distally to the spinal ganglion. Spinal nerves are mixed nerves. (p. 502; Fig. 13.6.) b. The ventral branches, except those in the thorax, which form the intercostal nerves, contribute to the major plexuses that supply the anterior and posterior trunks of the body and the extremities. The dorsal branches innervate the muscles and skin of the back (posterior trunk). (p. 502) 20. a. A plexus is a branching network of nerves formed by the roots of various spinal nerves that ensures that damage to a nerve root does not result in complete loss of innervation to that part of the body. (p. 502) b. See numbers. 13.8 to 13.11 and Tables 13.3 to 13.6, pp. 504–510, for detailed information on each of the four plexuses. 21. The ipsilateral reflex is a reflex elicited and affecting the same side of the body; Contralateral reflexes involve a reflex that starts on one side of the body and affects the other side. (p. 519) 22. The flexion or withdrawal reflex is a protective mechanism to withdraw from a painful stimulus, resulting in loss of pain. (p. 518) 23. Flexor reflexes are overpowering, polysynaptic, ipsilateral protective reflexes. Crossed stretch reflexes consist of an ipsilateral withdrawal reflex and a contralateral stretch reflex, which usually helps with balance. (pp. 518-519) 24. The sensory input of a crossed stretch reflex illustrates parallel processing, an ipsilateral response to a stimulus. The serial processing phase consists of motor activity, the contralateral response, which activates the extensor muscles on the opposite side of the body. (p. 519) 25. Reflex tests assess the state of the nervous system. Exaggerated, distorted, or absent reflexes indicate degeneration or pathology of specific regions of the nervous system, often before other signs appear. (p. 519) Copyright © 2010 Pearson Education, Inc.

Chapter 13

The peripheral nervous system and reflex activity.

26. Dermatomes are related to the regions of sensory innervation of spinal nerves. Spinal nerves correlate with the segmented body plan, as do muscles (at least embryologically). (p. 510)

Critical Thinking Questions and Clinical Applications 1. Precise realignment of severed and regenerated axons with their previous effector targets is highly unlikely. Nerve-muscle coordination has to be re-learned. Also, not all damaged fibers regenerate. (p. 492) 2. He would have trouble flexing his right foot dorsally and the knee joint would be unstable (more side-to-side rocking of the femur on the tibia). (pp. 515 and 516) 3. The brachial plexus was damaged when he suddenly broke his fall by holding on to the branch. (p. 505) 4. The left trochlear (IV) nerve, which innervates the superior oblique muscle responsible for this action. (p. 493) 5. The region of motor and sensory loss follows the course of the sciatic nerves (and their subdivisions); therefore they must have been badly damaged by the shooting accident. (p. 510) 6. Specific ascending pathways in the sphenoidal cord carry discriminatory tactile information from the upper extremities to the cortex. You need to use feature abstraction and possibly pattern recognition to identify a specific pattern feature, e.g. B. the teeth on a key or the hair on a rabbit's foot. (p. 490) 7. The right facial nerve was affected. This condition is called Bell's palsy and is often caused by herpes simplex 1 virus infection (p. 498).

Recommended reading Cox, James J., et al. "SCN9A canalopathy causes a congenital inability to feel pain." Nature 444 (December 2006): 894–898. Gillespie, P.G. and R.G. Walker. "Molecular Basis of Mechanosensory Transduction". Nature 413 (6852) (Sept. 2001): 194-202. Hunt, Stephen P., and Patrick W. Mantyh. "The Molecular Dynamics of Pain Control". Nature Reviews: Neuroscience 2(2) (February 2001): 83-91. Julius, D. and A.I. bas tree. "Molecular Mechanisms of Nociception". Nature 413 (6852) (2001 Sep): 203-210. Konstantinos, Meletis, et al. "Spinal cord injury reveals multilineal differentiation of ependymal cells". PLoS Biology 6(7) (July 2008). Kwon, BK, CG Fisher, M.F. Dvorak, and W. Tetzlaff. "Strategies to Promote Neural Repair and Regeneration After Spinal Cord Injury". Spine 30 (17 Sep 2005): S3–S13. Raineteau, Oliver, and Martin E. Schwab. "Plasticity of motor systems after incomplete spinal cord injury". Nature Reviews: Neuroscience 2 (4) (April 2001): 263-273. Yang, Jay, and Christopher L. Wu. "Gene therapy for pain". American Scientist 89(2) (March/April 2001): 126-135. Zuker, Charles S. "A Cold Ion Channel." Nature 416 (6876) (2002 Mar): 27-28.

Copyright © 2010 Pearson Education, Inc.

167

14

The autonomic nervous system

Aims Introduction 1. Define the autonomic nervous system and explain its relationship to the peripheral nervous system. 2. Compare the somatic and autonomic nervous systems in terms of effectors, efferent pathways, and released neurotransmitters. 3. Compare and contrast the functions of the parasympathetic and sympathetic nervous system. Anatomy of the ANS 4. For the parasympathetic and sympathetic parts, describe the site of origin of the CNS, the location of the ganglia, and the general pathways of the fibers. ANS physiology

6. Describe the clinical significance of drugs that mimic or inhibit adrenergic or cholinergic effects. 7. Describe the effects of the parasympathetic and sympathetic nervous system on the following organs: heart, blood vessels, gastrointestinal tract, lungs, adrenal medulla and external genitalia. 8. Describe the control of the autonomic nervous system. ANS homeostatic imbalance 9. Explain the association between some types of hypertension, Raynaud's disease and autonomic dysreflexia with disorders of autonomic function. Aspects of ANS development 10. Describe some effects of aging on the autonomic nervous system.

5. Define cholinergic and adrenergic fibers and list the different types of their receptors.

Suggested Lesson Plan I. Introduction (pp. 526-528, Figs. 14.1-14.2) A. Comparison of the somatic and autonomic nervous systems (pp. 526-527; Fig. 14.2) 1. The somatic nervous system stimulates skeletal muscle, whereas the ANS stimulates cardiac and innervates smooth muscles and glands. 2. In the somatic nervous system, the cell bodies of neurons are located in the spinal cord, and their axons extend to the skeletal muscles that innervate them. The ANS consists of a chain of two neurons.

168 Copyright © 2010 Pearson Education, Inc.

Chapter 14

The autonomic nervous system

3. The neurotransmitter released by somatic motoneurons is acetylcholine, which always has an excitatory effect; the neurotransmitters released by the ANS are epinephrine and acetylcholine, both of which can be excitatory or inhibitory. 4. There is an overlap between the somatic and autonomic nervous systems, and most of the body's responses to various internal and external stimuli involve both skeletal muscle activity and visceral organ responses. B. Departments of the Autonomic Nervous System (pp. 527-528; Fig. 14.1) 1. The parasympathetic department minimizes the body's energy expenditure while controlling the activities of digestion and elimination. 2. The sympathetic prepares the body to respond (or vigorously exercise) to an emergency or threat.

II. Anatomy of the ANS (pp. 528-535; Figs. 14.3-14.8; Box 14.1) A. Parasympathetic (craniosacral) division (pp. 529-530; Figs. 14.3-14.4; Box 14.1) 1. Preganglionic axons divide and go from the CNS almost to the structures to be innervated, where they synapse with ganglion neurons in the terminal ganglia. 2. The cranial outlet consists of preganglionic fibers that pass via the cranial oculomotor, facial, glossopharyngeal, and vagus nerves. 3. The remainder of the colon and pelvic organs are supplied by the sacral tributary originating from neurons located in the lateral gray matter of spinal cord segments S2-S4. B. Sympathetic (thoracolumbar) part (pp. 530-534; Figs. 14.3, 14.5-14.6; Table 14.1) 1. The sympathetic part supplies the visceral organs in the internal body cavities, but also all visceral structures in the upper part of the body Body Somatic Body 2. When synapses are formed in chain ganglia, postganglionic axons enter the ventral (or dorsal) branches of adjacent spinal nerves via the communicating branches called the gray communicating branches. 3. T5 inferior preganglionic fibers synapse in collateral ganglia; Therefore, these fibers move in and out of sympathetic chains without synapses. 4. Some fibers of the thoracic splanchnic nerves synapse with the hormone-producing marrow cells of the adrenal cortex. C. Visceral sensory neurons are the first link in autonomic reflexes, sending information about chemical changes, stretching, and irritation of the viscera (pp. 534-535; Figs. 14.7-14.8).

3. ANS physiology (pp. 535-540; Fig. 14-9; Tables 14.2-14.5) A. Neurotransmitters and receptors (pp. 535-536; Table 14.2) 1. Cholinergic receptors, such as nicotinic and muscarinic receptors, bind of acetylcholine. 2. Alpha and beta adrenergic receptors bind epinephrine. B. Knowing the locations of the cholinergic and adrenergic receptor subtypes allows the prescription of specific drugs to achieve the desired inhibitory or stimulatory effects in the target organs (pp. 535–536; Table 14–3).

Copyright © 2010 Pearson Education, Inc.

169

170

C. Interactions of Autonomous Areas (pp. 536–539; Table 14.4) 1. Most visceral organs are doubly innervated by both areas of the ANS, allowing dynamic antagonism between areas and precise control of visceral activity. 2. The sympathetic increases the heart rate, dilates the airways, and inhibits digestion and elimination when the body is under stress. 3. Once the stress is over, the parasympathetic nervous system returns heart rate and airway diameter to normal, allowing digestion and elimination to resume. 4. Sympathetic tone throughout the vasculature allows the firing rate of sympathetic neurons to control blood vessel diameter and regulate systemic blood pressure. 5. Parasympathetic tone is often dominant in the heart, digestive system, and urinary tract, maintaining normal homeostatic levels of functioning unless overridden by the sympathetic system during stress. 6. The departments of the autonomic nervous system can work together rather than antagonistically, as in sexual arousal. 7. The sympathetic system plays a unique role in controlling the adrenal medulla, sweat glands, arrector pili muscles, kidneys and most blood vessels. 8. The parasympathetic exerts localized and short-lived control over its effectors, while the effects of the sympathetic are persistent and widespread. D. Control of Autonomic Functions (pp. 539-540, Fig. 14.9) 1. The brainstem appears to exert the most direct influence on autonomic functions. 2. The hypothalamus is the main integrative center of the autonomic nervous system. 3. Cortical or voluntary control of the autonomic nervous system seems possible.

4. ANS Homeostatic Imbalance (p. 540-541) A. Hypertension or hypertension may be due to an overactive sympathetic vasoconstrictor response due to sustained high levels of stress (p. 540). B. Raynaud's disease is characterized by intermittent attacks causing the skin on the fingers and toes to become pale, then cyanotic and painful (pp. 540-541). C. Autonomic dysreflexia is a life-threatening condition in which autonomic and somatic motor neurons fire uncontrollably (p. 541).

V. Developmental aspects of the ANS (p. 541) A. Embryonic and fetal development of the autonomic nervous system (p. 541). 1. The preganglionic neurons and the somatic motor neurons of the ANS originate in the embryonic neural tube. 2. The ANS structures (ganglionic neurons, adrenal medulla and all autonomic ganglia) found in the PNS originate from the neural crest. 3. Nerve growth factor is a protein secreted by the target cells of postganglionic axons. B. With age, the efficiency of the ANS begins to decline, in part due to structural changes in some preganglionic axon terminals (p. 541).

Copyright © 2010 Pearson Education, Inc.

Chapter 14

The autonomic nervous system

Cross-references For more information on the topics covered in Chapter 14, see the chapters listed below. 1. Chapter 3: Membrane Functions; membrane receptors 2. Chapter 4: nerve tissue 3. Chapter 11: membrane potentials; neural integration; serial and parallel processing; synapse; Neurotransmitters 4. Chapter 12: Ascending and descending pathways of the spinal cord; spinal roots; gray and white matter of the spinal cord 5. Chapter 18: The role of sympathetic and parasympathetic (and epinephrine and norepinephrine) in the spinal cord's control of heart rate 6. Chapter 19: Sympathetic control of vessel diameter blood vessels 7. Chapter 23: Control Sympathetic and parasympathetic Control of Digestive Processes 8. Chapter 25: Sympathetic Control of Blood Vessels to the Kidney; Parasympathetic Pelvic Splanchnic Nerves and Urinary System 9. Chapter 27: Sympathetic and Parasympathetic Effects on Human Sexual Response

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 21: Spinal cord, spinal nerves and autonomic nervous system 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 21: Spinal Cord, Spinal Nerves, and Autonomic Nervous System

Teaching Tips 1. Because the autonomic nervous system is more complex than the somatic nervous system, it is worth spending some time comparing and contrasting the anatomy of both. 2. Figure 14.4 is a good 3D representation of the parasympathetic pathways; However, as an early introduction during the lesson, it may be helpful to use the enlarged slide in Figure 14.3 or to draw a 2-D schematic diagram of the sympathetic and parasympathetic pathways so that the class can logically follow the structure of the circuit. and understand what "connected" appears. Then guide the students through the general construction shown in Figure 14.4, p. 529. 3. Emphasize that somatic efferent pathways consist of a motor neuron cell body in the CNS, whose axon extends through the PNS to directly innervate the skeletal muscle effector. In contrast, the autonomic efferent pathways follow the same general plan, but consist of two motor neurons connected in series. 4. Point out that in many cases sympathetic and parasympathetic synapses use different neurotransmitters, a key feature in the dual nature of autonomic function. This will be illustrated when discussing the fight/flight and rest/digestion responses. 5. Many students struggle with the idea of ​​neurotransmitter/receptor function. Point out that many substances that are chemically similar to the actual neurotransmitter are capable of eliciting the same response. Emphasize that it is the binding of a substance to a receptor that triggers the cellular response.

Copyright © 2010 Pearson Education, Inc.

171

172

Text and Media Human Anatomy and Physiology Teacher Guide 6. When describing sympathetic and parasympathetic tone, emphasize the excitatory versus inhibitory nature of many responses. Then present the rate of fire as a touch on the table. As heart rate increases, responsiveness increases and vice versa, resulting in a change in ANS responsiveness. 7. Emphasize that there is a constant level of parasympathetic stimulation (tone) in many visceral organs and that there is enough sympathetic stimulation to keep the systems in homeostasis.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Without announcing what you are going to do, enter the classroom quietly, take your notes, and shout loudly (to startle the students). Then ask each student to make a list of all the organs involved and the effects. 3. Obtain a preserved cat and dissect it to expose the sympathetic nerve trunk, celiac ganglia, splanchnic nerves, and other parts of the ANS. 4. Obtain a 3D model of a longitudinal and cross-sectional view of the spinal cord, showing parts of the ANS and specifically the sympathetic, gray and white branches.

Critical Thinking/Discussion Points 1. Describe the role of beta-blockers in the treatment of certain types of visceral disorders. 2. At certain times, when people are very excited or in a sudden shock, their bowel and/or urinary sphincters get out of control. As for the role of ANS, why is that? 3. Some people often catch a cold after a very stressful event, like final exams. Is there a connection between the SNA, stress and the occurrence of a disease? 4. Most people feel very tired after a large meal. There? 5. How can biofeedback be used to reduce the effects of constant pain and stress? 6. Why is the sympathetic effect diffuse and long-lasting while the parasympathetic effect is local and short-lived? What would happen to the body systems in a stressful situation if these traits were reversed? How should the anatomy be modified? 7. Vagotomy is an operation in which a branch of the vagus nerve is severed. It is widely used to eliminate gastric parasympathetic stimulation in hypersecretion of gastric juice. What would be the consequences of cutting the entire nerve instead of just a specific branch?

Library research topics 1. Do all animals have an autonomic nervous system? If so, is it more or less advanced than ours? 2. The ANS regulates the peristaltic waves of the gastrointestinal tract. What would happen if the ganglia and/or the fibers that control this activity were damaged? What bacteria or type of trauma can cause this? 3. Ulcers seem to occur in people with high blood pressure. What are the causes of this problem and what is the treatment? 4. Nicotine and muscarine are substances that bind to specific receptors. What exactly are these receptors? Draw a cell membrane and visualize what the receptors would look like.

Copyright © 2010 Pearson Education, Inc.

Chapter 14

The autonomic nervous system

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all chapter-specific online media resources for Chapter 14 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 14.1 Introduction (pp. 526-528) Section 14.2 Anatomy of the ANS (pp. 528-535) MP3 Tutor Session: Differences between the sympathetic and parasympathetic nervous systems Memory Game: Autonomic Pathways Memory Game: The Major Ganglia of the ANS Autonomous Nervous System Section 14.3 Physiology of the ANS (pp. 535-540) Section 14.4 Homeostatic imbalance of the ANS (pp. 540-541) Case study: nervous tissue Case study: cardiac arrhythmias Section 14.5 Developmental aspects of the ANS (p. 541 ) Chapter summary Crossword 14.1 Web links Chapter tests Art lettering test Matching test Multiple- Choice test chapter practice test practice test study tools histology atlas myeBook flashcards glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For AV vendor information, see the AV Resource Guide in Appendix A. Copyright © 2010 Pearson Education, Inc.

173

174

Text and media guide to human anatomy and physiology

Video 1. Biologix Nerve Impulse Conduction (DE; 29 min., 1997). This video explores the electrochemical nature of nerve impulse conduction and transmission. He uses simulations to analyze the different levels of membrane potential and presents studies of how chemicals affect membrane potential. 2. Brain and Nervous System: Your Information Superhighway (FHS; 31 min, 1998). This program explores the brain and nervous system using the analogy of computers and the Internet. 3. Stress management (ESF; 19 min.). Show the difference between positive stress, which boosts the immune system, and negative stress, which can increase the likelihood of illness. 4. Neural connection video (WNS; 30 min). This introductory video illustrates the biochemical and cellular properties of the nervous system and how the vertebrate neural network works. Discuss the wide variety of sensory cells that all organisms larger than a single cell possess in one way or another.

A.D.A.M.® Interactive Anatomy® 4.0 software (see full list on page 9 of this manual). A.D.A.M.® MediaPro (see page 9 of this manual for a complete list). A.D.A.M.® Anatomy Practice (see page 87 of this manual for a complete list). Set of 10 interactive physiology systems: Nervous System I & II (see page 137 for full list). 5. Practice Anatomy Lab™ 2.0: Human Cadaver Anatomical Models (See page 9 of this guide for a complete list). 6. The Ultimate Human Body, version 2.2 (see page 9 of this manual for a complete list). 1st 2nd 3rd 4th

Material to improve the lesson Thumbnails of all illustrations in Chapter 14 can be found in Appendix B.

Figure 14.1 Figure 14.2 Figure 14.3 Figure 14.4 Figure 14.5 Figure 14.6 Figure 14.7 Figure 14.8 Figure 14.9 Table 14.1 Table 14.2 Table 14.3 Table 14.4 Make connections

Position of the ANS in the structural organization of the nervous system. Comparison of the somatic and autonomic nervous systems. General description of the subdivisions of the SCN. Parasympathetic division of the ANS. Sympathetic tribes and railways. Sympathetic division of the ANS. visceral reflexes. Referred pain card. SNA Control Planes. Anatomical and Physiological Differences Between the Parasympathetic and Sympathetic Portions Cholinergic and Adrenergic Receptors Selected Classes of Drugs Affecting Autonomic Nervous System Activity Effects of the Parasympathetic and Sympathetic Portions on Various Organs Homeostatic Interrelationships Between the Nervous System and Other Body Systems Copyright © 2010 Pearson Education, Inc . . .

Chapter 14

The autonomic nervous system

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 6. The involuntary nervous system is used to reflect your subconscious control; The visceral-emotional system reflects the fact that the hypothalamus is the primary regulatory center for both emotional (limbic) response and visceral control. The term visceral also indicates the location of most of its effectors. (p. 526) 7. The white communicating branches contain myelinated preganglionic fibers which leave the spinal nerve and enter the sympathetic trunk; The gray communicating branches represent postganglionic fibers, are not myelinated, and enter the spinal nerve to proceed to their final destination. (pp. 530 to 532) 8. Sweat glands: increase sweat production; Pupils of the eyes - dilate (widen); Adrenal medulla: releases norepinephrine and epinephrine; Heart: increased frequency and force of contraction; lungs - bronchodilation; Liver: glycogenolysis and release of glucose into the blood; Blood vessels to skeletal muscles - dilatation; Blood vessels to the digestive organs - narrowing; Salivary glands: Narrowing of the blood vessels that supply the gland, reducing saliva production. (p. 538) 9. All except effects on the adrenal medulla, liver and blood vessels. (p. 538) 10. All preganglionic and postganglionic fibers of the parasympathetic part secrete acetylcholine. Some postganglionic sympathetic fibers secrete acetylcholine. Only the postganglionic fibers of the sympathetic nervous system release norepinephrine. (p. 535) 11. "Tone" in ANS divisions refers to the frequency of firing of sympathetic and parasympathetic neurons. Sympathetic tone determines the degree of constriction or dilation throughout the vasculature under resting conditions, while parasympathetic tone is important in determining heart rate and GI function. The resting tone of each system helps maintain homeostasis under normal conditions. (p. 537) 12. Acetylcholine: nicotine and muscarine; Norepinephrine - Alpha 1, Alpha 2, ß1, ß2. See Table 14.3 for the main locations. (pp. 535 and 536) 13. The nuclei of the reticular formation of the brainstem, especially those of the medulla oblongata. (p. 540) 14. The hypothalamus is the main integrative center that coordinates heart rate, blood pressure and body temperature. (p. 539) 15. The premise of biofeedback training is that we do not exercise routine voluntary control over our visceral activities because we are poorly aware of our internal environment. The training allows participants to become aware of their body's signals and then make subtle internal changes that help them manage things like migraines and stress. (p. 540) 16. Elderly people often complain of constipation and dry eyes and faint when changing position, e.g. B. Standing up suddenly after sitting down. (p. 541) 17. The cell body of the preganglionic neuron lies in the CNS, while the cell body of the ganglion neuron lies in the autonomic ganglion, not distal ("post") to the ganglion. However, its axon is distal to the ganglion, hence the term postganglionic axon is correct. (p. 526)

Questions of Critical Thinking and Clinical Application 1. Parasympathetic stimulation of the bladder through the release of acetylcholine increases bladder tone and relaxes the urinary sphincters, a result reproduced by bethanechol. Mr. Johnson's insanity would be the result of low blood pressure due to a low heart rate. Your wheezing is due to narrowed airways. This Copyright © 2010 Pearson Education, Inc.

175

176

Text and media guide to human anatomy and physiology

2.

3.

4. 5.

Two symptoms, along with decreased tear flow, diarrhea, spasms, and unwanted penile erection, are all parasympathetic effects that have been enhanced by the parasympathomimetic effects of your drug. (p. 538) Referred pain is the sensation of pain that appears to originate from a location other than the pain stimulus. Damage to the heart results in pain impulses entering the spinal cord in the thoracic region and also receiving impulses from the left chest and left arm. (p. 535) Nicotine can cause vasospasm, causing skin temperature to drop, which can trigger a seizure. In addition, drugs prescribed for Raynaud's disease are vasodilators and nicotine would interfere with their effects. (pp. 540-541) Tiffany may experience temporary dizziness, blurred vision, dry mouth, constipation, and difficulty urinating or incontinence. (p. 537) Smell stimulates the olfactory nerves and transmits information to the CNS. The response is parasympathetic activation, which stimulates increased secretion from the salivary glands (mouthwash) and increased gastric secretory activity and motility (stomach growl). (p. 538)

Recommended Reading Ebadi, Manuchair. Pharmacodynamic principles of phytotherapy. 2nd ed. Boca Raton: CRC Press, 2007. Herbert, W. "Punching the Biological Timeclock." Science News 122 (July 1982). House, MA "Cocaine". American Journal of Nursing 90 (April 1990): 40-45. Kalin, N.H. "The Neurobiology of Anxiety." Scientific American 268 (May 1993): 94. Kaufmann, H., K. Nahm, D. Purohit and D. Wolfe. "Autonomic failure as the initial presentation of Parkinson's disease and Lewy body dementia". Neurology 63 (May 2004): 1093–95. Revkin, A. "The Huntington's Hunt." Discover (December 1993): 100. Simpson, S. "Pain, Pain, Go Away." Science News 155 (February 1999): 108-110.

Copyright © 2010 Pearson Education, Inc.

fifteen

special senses

Goals

The chemical senses: taste and smell

The eye and seeing 1. Describe the structure and function of the ocular ancillary structures, the layers of the eye, the lens and the humors of the eye. 2. Describe the causes and consequences of cataracts and glaucoma. 3. Trace the path of light through the eye to the retina and explain how light is focused for distance and near vision. 4. Describe the causes and consequences of astigmatism, myopia, hyperopia and presbyopia. 5. Describe the events involved in the stimulation of photoreceptors by light and compare and contrast the role of rods and cones in vision. 6. Compare and contrast light and dark adaptation. 7. Trace the visual pathway to the visual cortex and briefly describe the steps of visual processing.

8. Describe the location, structure and afferent pathways of taste and smell receptors and explain how these receptors are activated. The Ear: Hearing and Balance 9. Describe the general structure and function of the outer, middle and inner ear. 10. Describe the sound conduction pathway to the fluids of the inner ear and trace the auditory pathway from the spiral organ (of Corti) to the temporal cortex. 11. Explain how someone can distinguish between pitch and loudness and locate the source of noise. 12. List the possible causes and symptoms of otitis media, deafness and Meniere's syndrome. 13. Explain how the balance organs in the semicircular canals and vestibule help maintain dynamic and static balance. Aspects of the development of the special senses 14. Name the changes that occur in the special senses with age.

Suggested Lesson Plan I. The Eye and Sight (pp. 548-569; Figs. 15.1-15.20) A. Sight is our predominant sense; 70% of our body's sensory receptors are located in the eye (p. 548). B. Accessory Structures of the Eye (pp. 548-551; Figs. 15.1-15.3) 1. The eyebrows are short, coarse hairs that cover the supraorbital rims of the eye and protect the eyes and prevent perspiration. 2. The eyelids (palpebrae), eyelashes and associated glands help protect the eye from physical danger and dryness.

177 Copyright © 2010 Pearson Education, Inc.

178

Text and media Teacher's manual of human anatomy and physiology 3. The conjunctiva is a transparent mucous membrane that lines the eyelids and the whites of the eyes. Creates a lubricating mucus that prevents the eye from drying out. 4. The lacrimal apparatus consists of the lacrimal gland, which secretes a dilute saline solution that cleans and protects the eye when lubricated, and ducts that drain excess fluid into the nasolacrimal duct. 5. The movement of each eyeball is controlled by six extraocular muscles innervated by the oculomotor and trochlear nerves. C. Structure of the Eyeball (pp. 551-556; Figs. 15.4-15.9) 1. Three layers form the wall of the eyeball. a. The tunica fibrosa is the outermost layer of the eye and is made up of dense avascular connective tissue with two regions: the sclera and the cornea. B. The tunica vascularis (uvea) is the middle layer and has three regions: the choroid, the ciliary body, and the iris. C. The inner layer (retina) is the innermost layer, which consists of two layers: the outer pigmented layer absorbs light; The inner nerve layer contains millions of photoreceptors (rods and cones) that convert light energy. 2. Internal Chambers and Fluids a. The posterior segment (base) is filled with a clear gel called the vitreous humor, which transmits light, supports the posterior surface of the lens, holds the retina close to the pigment layer, and contributes to intraocular pressure. B. The anterior segment (cavity) of the eye is filled with aqueous humor, which supplies the lens and cornea with nutrients and oxygen while carrying waste away. 3. The lens is a flexible, transparent, biconcave, avascular structure that can change shape to allow precise focusing of light on the retina. D. Physiology of vision (pp. 556-569; Figs. 15.10-15.20) 1. General description: light and optics a. Electromagnetic radiation includes all energy waves, from longwave to shortwave, and includes visible light, which our eyes see as color. B. Refraction of a ray of light occurs when it strikes the surface of another medium at an oblique angle rather than at a right angle. 2. Concentration of light on the retina a. Light is diffracted three times: when it enters the cornea and when it enters and exits the lens. B. Far viewpoint is the distance beyond which no change in lens shape is required (approximately 6 meters or 20 feet). C. Focusing for near vision requires the eye to make three adjustments: lens accommodation, pupillary constriction, and eyeball convergence. i.e. Nearsightedness, or nearsightedness, occurs when objects are focused in front of the retina and close objects appear smooth but distant objects appear blurry. Y. Farsightedness, or farsightedness, occurs when objects become focused behind the retina, causing distant objects to be seen clearly but close-up objects to appear blurry. 3. Photoreception is the process by which the eye perceives light energy. a. Photoreceptors are modified neurons structurally resembling tall epithelial cells.

Copyright © 2010 Pearson Education, Inc.

Chapter 15

4.

5.

6.

7.

8.

9.

special senses

B. The rods are very delicate and are best used for night vision. The cones are less sensitive to light and better adapted to bright light and color vision. C. Photoreceptors contain a light-absorbing molecule called retinal. Stimulation of Photoreceptors a. The visual pigment of the rods is rhodopsin, which is formed and broken down within the rods. B. The breakdown and regeneration of cone visual pigments is essentially the same as for rhodopsin. Exposure of the photoreceptors to light causes pigment breakdown that hyperpolarizes the receptors, thereby inhibiting the release of the neurotransmitter that carries the information. Light adaptation occurs when we move from darkness to bright light. The sensitivity of the retina decreases drastically and the neurons in the retina change from a rod to a cone system. Dark adaptation occurs when we move from a well-lit area to a dark one. The cones stop working and rhodopsin begins to accumulate in the rods, increasing the sensitivity of the retina. Visual pathway to the brain a. Ganglion cells of the retina fuse at the back of the eyeball and become the optic nerve, which crosses the optic disc to become the visual pathways. B. The visual pathways send their axons to neurons within the lateral geniculate body of the thalamus. C. Axons from the thalamus project through the internal capsule to form optical radiation from fibers in the brain's white matter. These fibers project to the primary visual cortex in the occipital lobe. Visual processing occurs when exposure of photoreceptors to light hyperpolarizes them, causing bipolar rod-cone neurons to send signals to their ganglion cells.

II. The chemical senses: taste and smell (pp. 569-574; Figs. 15.21-15.24) A. Taste and smell receptors are chemoreceptors that respond to chemicals in solution (p. 569). B. Olfactory Epithelium and the Sense of Smell (pp. 569-571; Figs. 15.21-15.22) 1. The olfactory epithelium is the olfactory organ in the roof of the nasal cavity. 2. Olfactory receptors are bipolar neurons with a thin apical dendrite ending in a bud with multiple olfactory cilia. 3. In order to smell a given odorant, it must be volatile and soluble in the fluid lining the olfactory epithelium, which stimulates the olfactory receptors. 4. In olfactory transduction, an odorant binds to the olfactory receptor, a G protein, and the second messenger cyclic AMP. 5. Axons from olfactory receptor cells synapse in the olfactory bulbs and send impulses through the olfactory tracts to the thalamus, hypothalamus, amygdala, and other members of the limbic system. C. Taste Buds and the Sense of Taste (pp. 571 and 573; Figs. 15.23 and 15.24) 1. Taste buds, the sense organs of taste receptors, are located in the oral cavity, most of them in the tongue. 2. Taste sensations can be classified into one of five basic qualities: sweet, sour, bitter, salty and umami.

Copyright © 2010 Pearson Education, Inc.

179

180

Text and Media Human Anatomy and Physiology Teacher Guide 3. Physiology of Taste a. In order for a chemical to be tasted, it must be dissolved in saliva, pass through the taste pore, and come into contact with a taste thread. B. Each taste sensation seems to have its own specific transmission mechanism. 4. The afferent fibers that carry taste information from the tongue are mainly located in the facial nerve and cranial nerves of the glossopharynx. 5. Taste impulses from the few taste buds in the epiglottis and lower pharynx are transmitted through the vagus nerve. 6. Taste is strongly influenced by smell and by the stimulation of thermoreceptors, mechanoreceptors and nociceptors. D. Homeostatic Imbalances of the Chemical Sense (p. 573) 1. Anosmias are olfactory disorders resulting from head injury, severe olfactory nerves, inflammation of the nasal cavity, or aging. 2. Uncinate attacks are olfactory hallucinations. 3. Taste disturbances are less common but can be caused by respiratory infections, head trauma, chemicals, medications, or radiation to the head and neck.

3. The Ear: Hearing and Balance (pp. 574-588; Figs. 15.25-15.38) A. Structure of the Ear (pp. 574-577; Figs. 15.25-15.28) 1. The outer ear consists of the pinna. and the external auditory canal, which is covered by hair with skin, sebaceous and cerumen glands. 2. The middle ear or tympanic cavity is a small air-filled, mucosa-lined cavity in the petrous bone of the temporal bone. It is traversed by the auditory ossicles. 3. The inner ear has two main areas: the bony labyrinth and the membranous labyrinth. a. The vestibule is the central cavity of the bony labyrinth with two membranous sacs attached to the perilymph, the sacculus, and the utricle. B. Semicircular canals project from the posterior part of the vestibule, each of which contains an equilibrium receptor region called the crista ampullaris. C. The snail-shaped spiral cochlea extends from the front of the vestibule and contains the cochlear duct, which houses the helix (organ of Corti), the receptors for hearing. B. Physiology of hearing (pp. 577-583; Fig. 15.29-15.33) 1. Sound properties a. Sound is a pressure disturbance created by a vibrating object and propagated by the molecules in the medium. B. Frequency is the number of waves that pass a given point in a given time. C. The amplitude or height of the wave indicates the intensity of a sound (loudness). 2. The sound of air entering the external ear canal hits the eardrum and causes it to vibrate. 3. Basilar membrane resonance mechanically processes sound signals before they reach receptors. 4. The transmission of sound stimuli occurs after the trapped stereocilia of hair cells are deflected by localized movements of the basilar membrane. 5. Impulses generated in the cochlea travel through the spiral ganglion along the afferent fibers of the cochlear nerve to the cochlear nuclei of the medulla oblongata, the superior olivary nucleus, the inferior colliculus, and finally the auditory cortex. Copyright © 2010 Pearson Education, Inc.

Chapter 15

special senses

6. Auditory processing involves perceiving pitch, recognizing loudness, and locating sounds. C. Auditory Homeostatic Imbalances (p. 583) 1. Deafness is any hearing loss, however slight. 2. Tinnitus is a ringing or clicking noise in the ears without auditory stimuli. 3. Ménière's syndrome is a labyrinthine disorder that causes a person to have repeated bouts of dizziness, nausea, and vomiting. D. Balance and Orientation (pp. 584-587; Figs. 15.34-15.37) 1. The sense of balance is responsive to various head movements and depends on input from the inner ear, vision and information from stretch receptors in the muscles. and tendons 2. The sensory receptors for static balance are the maculae. 3. The dynamic balance receptor is the crista ampullaris, located in the ampulla of the semicircular canals and activated by head movements. 4. Information from the equilibrium receptors goes directly to the reflex centers in the brainstem, not to the cerebral cortex.

4. Developmental Aspects of the Special Senses (pp. 588-589) A. Taste and Smell (p. 588) 1. Smell and taste are highly developed at birth. 2. Women generally have a more keen sense of taste and smell than men. 3. From the fourth decade of life, the ability to taste and smell decreases because receptors are replaced more slowly than in younger people. B. Vision (p. 588) 1. In the fourth week of development, the eyes begin to develop and connections to the CNS are made even before the development of photoreceptors. 2. Sight is the only sense that is not fully developed at birth. Newborns only see in shades of gray, exhibit uncoordinated eye movements, and often only use one eye at a time. 3. By 5 months vision has improved and by 5 years vision is well developed. 4. With age, the lens becomes less clear and the pupil partially narrows, causing a decrease in visual acuity in people over 70 years old. C. Hearing and Balance (pp. 588-589) 1. Hearing begins to develop in the embryo at 3 weeks. 2. Newborns can hear but react reflexively. From about the fourth month of life, hearing involves recognition. 3. With age, the ability to hear high-pitched sounds decreases and hearing loss is exacerbated by exposure to loud noise.

Cross-references For more information on the topics discussed in Chapter 15, see the chapters listed below. 1st 2nd 3rd 4th 5th

Chapter Chapter Chapter Chapter Chapter

4: epithelium; exocrine glands; connective tissue 5: sebaceous and sweat glands 8: synovial joints 10: naming of skeletal muscles 11: synapses; neurotransmitters

Copyright © 2010 Pearson Education, Inc.

181

182

Text and Media Teacher's Guide to Human Anatomy and Physiology 6. Chapter 12: Cerebral Cortex; thalamus; CSF formation (similar to aqueous humor formation) 7. Chapter 13: Receptor and generator potentials; cranial nerves; reflex activity; chemoreceptors 8. Chapter 21: Inflammation 9. Chapter 22: Relationship between the Eustachian tube and the respiratory system 10. Chapter 23: Secretion of saliva and gastric juice; salivary reflex; taste buds and buds

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 24: Special Senses: Vision Exercise 25: Special Senses: Hearing and Balance Exercise 26: Special Senses: Smell and Taste 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 24: Special Senses: Seeing. Exercise 25: Special Senses: Hearing and Balance. Exercise 26: Special senses: smell and taste

Teaching Tips 1. Emphasize that not every taste sensation is localized to a specific area, but that there is significant overlap between the different sensory areas. Students often assume that a certain point on the tongue only responds to one type of substance. 2. Emphasize the importance of other sensations (especially smell) in the perception of taste. 3. During the olfactory anatomy lesson, ask the class what would happen to the sense of smell if the mucous glands beneath the olfactory epithelium were absent. 4. Emphasize that olfactory receptors are the only renewable neurons in the body and are therefore the only exception to the rule that neurons do not replicate. 5. There is often confusion in the terminology of the cameras of the eye. Point out that the anterior segment of the eye is divided into anterior and posterior chambers by the iris. 6. Initially, it is difficult for students to understand the concept of ciliary muscle contraction, which leads to thickening of the lens (for near). Intuitively, most people think that the lens stretching process is the result of muscle contraction, not relaxation. Spend some time reinforcing this concept. 7. Ask students to focus on objects at night. Explain that they shouldn't be looking directly at the object, but slightly to the side, and the object should look brighter. Relate this exercise to the distribution of rods and cones in the eye. 8. As an interesting point, mention that the ossicles are connected by the smallest synovial joints in the body. 9. Emphasize the difference between static and dynamic balance by comparing and contrasting the anatomy of each balance type.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. Copyright © 2010 Pearson Education, Inc.

Chapter 15

special senses

2. Pick four volunteers and spritz different strengths of cologne on their wrists. Then determine how long it will take for everyone to "get used to" the colony. 3. Bring a convex lens to class and have students hold the lens and focus it on a distant object. You will find that it is upside down and reversed. Then explain that the human eye is also a single lens system. The question must be asked: "Why don't we see things backwards?" 4. Create a 3D model of an eye and an ear to illustrate the different anatomical parts of each. 5. Prepare a fresh (or preserved, if unavailable) bovine eye to visualize the anatomical structure and composition of the tissues and fluids. 6. Obtain a skull to illustrate the location of all bone structures related to the senses. 7. Get a set of ear bones to illustrate how tiny they are.

Critical Thinking/Points for Discussion 1. Most people with sinusitis cannot smell or taste. There? 2. Wine tasting can be a real art. Why do some people taste better than others? What influence do tobacco, alcohol and/or sweets have on wine tasting? Why is it helpful to swirl a glass of wine and then smell it? 3. Certain types of sunglasses can do more harm than good. What could be wrong with cheap sunglasses? 4. What would happen to the senses of taste and smell if the taste and smell receptors were specific to only one substance? 5. If the sclera is avascular, why do we see blood vessels in the white of the eye? 6. How is it possible that the cornea is transparent and the sclera is opaque when both are made of the same material and blend into each other? 7. Investigate the consequences on ocular anatomy and vision when aqueous outflow exceeds performance. 8. Explain why depth perception is lost when one eye is not working. 9. If the number of cones feeding a single ganglion cell were multiplied by ten, what would be the implications for color vision? 10. Investigate the consequences for sound perception when the tympanic membrane is doubled in area. What would happen if the oval window had an increased surface area? Would noise be heard if the round window were rigid?

Library Research Topics 1. How successful are cochlear implants? Which surgical techniques are used? 2. Some permanently deaf people have been helped through the use of computers and electrical probes attached to specific areas of the brain. How is this possible and what is the current state of research in this area? 3. Contact lenses have long been used to correct vision problems. What is the status of contact lens implants and why are ophthalmologists reluctant to perform them? 4. What substances are found in wines such as Cabernet, Chardonnay, Chenin Blanc and others that offer a wide variety of flavors and aromas? 5. If hearts, lungs and livers can be transplanted, why not eyes? What would be some of the technical difficulties?

Copyright © 2010 Pearson Education, Inc.

183

184

Text and media guide to human anatomy and physiology

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all chapter-specific online media resources for Chapter 15 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Aims Section 15.1 The Eye and Vision (pp. 548–569) MP3 Tutor Session: The Visual Path Artist Labeling: the eye and associated ancillary structures (Fig. 15.1b, p. 548) Artist Labeling: Internal Structures of the Eye (Fig. 15.4a, p. 552) Case study: Special senses: Vision Section 15.2 The chemical senses: Taste and smell (pp. 569-574) Memory game: Factors of sight and the art of smell Section 15.3 Hearing: Hearing and balance ( p. 574 –588) Art Labelling: Structure of the ear (Fig. 15.25a–b, p. 575) Section 15.4 Aspects of the development of the special senses (pp. 588–589) Chapter summary Memory game: sense organs Crossword puzzle 15.1 Crossword puzzle 15.2 Crossword puzzle 15.3 Crossword puzzle 15.4 Crossword puzzle 15.5 Web Links Chapter Quizzes Art Lettering Quiz Matching Quiz Multiple Choice Quiz True/False Quiz Chapter Practice Quiz Chapter Learning Tools Histology an Atlas myeBook flashcard glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Copyright © 2010 Pearson Education, Inc.

Chapter 15

special senses

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1. The eye: seeing comes from light (IM; 22 min., 2004). This DVD explores the structures and functions of the human eye. It covers topics such as the role of light in vision and the formation and transmission of images. 2. How Sweet It Is: Taste and Tasting (NIMCO; 22 min, 2001). Provides an introduction to the sense of taste, shows how tasting works, and discusses the role that smell plays in tasting. 3. The nose knows: smell and the nose (NIMCO; 23 min., 2001). Explore the olfactory organs and analyze the molecular structure of smells and how the brain interprets smells. 4. The Senses (FHS; 20 min., 1995). This show from The New Living Body series shows how the senses of sight and balance work and how they interact with each other. 5. Making Sense to the Senses (FHS; 56 min., 1997). Discover the beauty and complexity of visual, auditory, chemosensory and tactile perception.

A.D.A.M.® Interactive Anatomy® 4.0 software (see full list on page 9 of this manual). A.D.A.M.® MediaPro (see page 9 of this manual for a complete list). A.D.A.M.® Anatomy Practice (see page 87 of this manual for a complete list). Explore Perception (Win/Mac). It examines phenomena such as apparent motion, pitch perception, sensory adaptation, and visual and auditory illusions. 5. Practice Anatomy Lab™ 2.0: Human cadaver, anatomical models, histology (see full list on page 9 of this manual). 6. The Ultimate Human Body, version 2.2 (see page 9 of this manual for a complete list). 1st 2nd 3rd 4th

Materials to Improve Teaching Thumbnails of all the figures in Chapter 15 can be found in Appendix B.

Index Instructor Slide/Resource DVD Image Image Image Image Image Image

15,1 15,2 15,3 15,4 15,5 15,6 15,7

Figure Figure Figure Figure Figure Figure

15,8 15,9 15,10 15,11 15,12 15,13 15,14

The eye and the ancillary structures. The tear apparatus. Extrinsic Eye Muscles. Internal structure of the eye (sagittal section). Dilation and constriction of the pupil, anterior view. Microscopic anatomy of the retina. Part of the back wall (fundus) of the right eye as seen with an ophthalmoscope. circulation of the aqueous humor. Photo of a waterfall. The electromagnetic spectrum and photoreceptor sensitivities. Refraction. Diffraction of light by a convex lens. Focus for distance and near vision. Refraction Issues Copyright © 2010 Pearson Education, Inc.

185

186

Text and Media Teacher's Guide to Human Anatomy and Physiology figure figure figure figure figure

15,15 15,16 15,17 15,18 15,19 15,20

Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure

15,21 15,22 15,23 15,24 15,25 15,26 15,27 15,28 15,29 15,30 15,31 15,32 15,33 15,34 15,35 15,36 15, 37

retinal photoreceptors. Formation and degradation of rhodopsin. phototransduction events. Signal transmission in the retina. Visual pathway to the brain and to the visual fields, bottom view. Responses of central and decentered retinal ganglion cells to different types of illumination. olfactory receptors. odor transduction process. Location and structure of the taste buds on the tongue. The Taste Path Ear Structure. The three auditory ossicles and associated skeletal muscles. Membranous labyrinth of the inner ear. Anatomy of the Cochlea. Sound: source and propagation. Frequency and amplitude of sound waves. Sound wave path and basilar membrane resonance. Photo of the hair cells of the cochlea with their precise arrangement of stereocilia. The audio track. Structure of a macula. The effect of gravity on a macular receptor cell in the utricle. Location, structure and function of an ampoule ridge in the inner ear. Ways of the balance and orientation system.

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 30. The nasolacrimal duct opens into the nasal cavity. (p. 549) 31. The rods are visual receptors for dim light, while the cones are for bright light and sharp color vision. (p. 553) 32. The fovea is lateral to the optic disc. Contains only cones and provides a detailed color view for critical viewing. (p. 553) 33. Changes in the retina until it is completely remodeled; The retina-opsin combination tears and separates the retina and opsin (whitening). The net effect is to "turn off" sodium input into the cell, effectively hyperpolarizing the rod. (p. 562) 34. Each cone responds most strongly to one of these colors of light, but there is an overlap in their absorption spectra that explains the other hues. (p. 562) 35. The receptors are located in the roof of the nasal cavity. They are badly positioned because the air has to make a sharp upward curve to reach them. (p. 570) 36. Wrong. Each olfactory receptor has only one type of receptor protein but can bind to many different types of odorant molecules. (p. 570) 37. The five basic tastes are sweet, sour, salty, bitter and umami. Taste is served by cranial nerves VII (face), IX (glossopharyngeal), and X (vagus). (pp. 571 and 572)

Copyright © 2010 Pearson Education, Inc.

Chapter 15

special senses

38. With age, the lens enlarges, loses crystal clarity and discolours, and the iris dilator muscles become less efficient. Atrophy of the organ of Corti reduces hearing acuity, especially for high-pitched sounds. Smell and taste are reduced due to a gradual loss of receptors, which reduces appetite. (pp. 588 and 589)

Critical Thinking Questions and Clinical Application 1. Papilledema: a nipple-like bulge of the optic disc at the eyeball caused by conditions that increase intracranial pressure. An increase in CSF pressure caused by an intracranial tumor compresses the walls of the central vein, causing optic disc stasis and bulging. (p. 589) 2. Pathogenic microorganisms spread from the nasopharynx through the ear canal into the tympanic cavity. They may then spread posteriorly via the antrum mastoideum to the air cells of the mastoid, causing mastoiditis, and medial to the inner ear, causing secondary labyrinthitis. If not controlled, the infection can spread to the meninges, causing meningitis and possibly an abscess in the temporal lobe of the brain or cerebellum. They can also enter the blood and cause sepsis. The reason for his dizziness and loss of balance is a disturbance of the vestibular apparatus caused by labyrinthitis. (p. 574) 3. Conjunctivitis. The foreign body is probably in the conjunctival sac near the opening of the tear ducts. (p. 549) 4. This is called a retinal detachment. The condition is serious, but the retina can be surgically reattached with a laser before permanent damage occurs. (p. 553) 5. The inability to hear high-pitched sounds is called presbycusis, a type of sensorineural deafness. It is caused by the gradual loss of auditory receptors throughout life, but is accelerated when a person is exposed to loud rock music for long periods of time. (p. 589) 6. Blindness because visual impulses are prevented from reaching the papilla. (p. 566) 7. Albinism involves an inherited inability of melanocytes to synthesize tyrosinase, an enzyme necessary for the production of melanin, a light-absorbing pigment normally present in the choroid and pigmented layer of the retina. The lack of melanin allows light to be scattered and reflected in the eye, causing visual confusion. (p. 559) 8. Jan had tinnitus. (p. 583) 9. This condition could be a retinal detachment. (p. 553) 10. In addition to nausea and fatigue, chemotherapy can affect your sense of taste. (p. 573)

Recommended Reading Barinaga, Márcia. "The course of the smell is predetermined." Science 294 (5545) (November 2001): 1269-1271. Berson, David M. "Phototransduction by Retinal Ganglion Cells Adjusting the Circadian Clock." Science 295 (5557) (February 2002): 1070-1073. Cerius, Gregory. "Artificial Vision". Discover 22(8) (Aug 2001): 50–54. Cheung, Ning and others. "Quantitative assessment of early diabetic retinopathy using fractal analysis". Diabetes Care (October 2008): http://care.diabetesjournals.org/cgi/content/abstract/dc08-1233v1.

Copyright © 2010 Pearson Education, Inc.

187

188

Text and media manual for teachers of human anatomy and physiology Daugman, John. "Iris detection". American Scientist 89(4) (2001 Jul/August): 326-333. Flintstone, Stuart. "How the olfactory system makes flavors meaningful". Nature 413 (6852) (2001 Sep): 211-218. Frasnelli, J., B. Schuster, and T. Hummel. "People with congenital anosmia have stronger but similar peripheral central trigeminal responses." Cerebral Cortex 17(2) (February 2007): 370-377. GAGESCU, Raluca. "Listen, listen." Nature Reviews: Molecular Cell Biology 2(8) (2001 Aug): 565. Hattar, S., et al. "Melanopsin-containing retinal ganglion cells: architecture, projections, and intrinsic photosensitivity". Science 295 (5557) (February 2002): 1065-1070. Lindemann, B. "Receptors and Taste Transduction." Nature 413 (6852) (2001 Sep): 219-225. Nirenberg, SM, et al. “Retinal ganglion cells function largely as independent encoders.” Nature 411 (6838) (June 2001): 698–701. Oliver, Dominik and others. "Intracellular anions as a voltage sensor of prestin, the outer hair cell motor protein". Science 292 (5525) (2001 June): 2340-2343. Picaud, Franck and Claude Desplan. "A New View of Photoreceptors". Nature 416 (6877) (2002 Mar): 139-140. Stevens, David R., et al. "Hyperpolarization-activated channels HCN1 and HCN4 mediate responses to acidic stimuli". Nature 413 (6856) (October 2001): 631-635. Sun, Hui and Jeremy Nathans. "The Challenge of Macular Degeneration". Scientific American 285(4) (October 2001): 69-75. Weiss, Gisele. "Why is a mushy potato chip unappetizing?" Science 293 (5536) (September 2001): 1753–1754. wood, heather. "Sweet feeling." Nature Reviews: Neuroscience 2 (6) (June 2001): 382.

Copyright © 2010 Pearson Education, Inc.

the endocrine system

sixteen

Goals

main endocrine glands

The endocrine system: an overview

11. Describe the important effects of the two groups of hormones produced by the thyroid. 12. Follow the process of formation and release of thyroxine. 13. Give the general functions of parathyroid hormone. 14. Name the hormones produced by the adrenal gland and their physiological effects. 15. Briefly describe the importance of melatonin. 16. Compare and differentiate the effects of the two main pancreatic hormones. 17. Describe the functional role of hormones in the testes, ovaries and placenta.

1. Point out the important differences between the hormonal and neural controls of how the body functions. 2. Name the most important endocrine organs and describe their location in the body. 3. Distinguish between hormones, paracrine and autocrine. Hormones 4. Describe how hormones are classified chemically. 5. Describe the two main mechanisms by which hormones exert their effects on target tissues. 6. Name three types of interactions of different hormones acting on the same target cell. 7. Explain how the release of hormones is regulated. The Pituitary Gland and the Hypothalamus 8. Describe the structural and functional relationships between the hypothalamus and the pituitary gland. 9. Name and describe the main effects of the anterior pituitary hormones. 10. Analyze the structure of the posterior pituitary gland and describe the action of the two hormones it releases.

Secretion of hormones by other organs 18. Name a hormone produced by the heart. 19. Indicate the location of the enteroendocrine cells. 20. Briefly explain the hormonal functions of the kidney, skin, adipose tissue, bone and thymus gland. Developmental aspects of the endocrine system 21. Describe the effects of aging on the functioning of the endocrine system.

Suggested Lesson Plan I. The Endocrine System: An Overview (pp. 595-596; Fig. 16.1) A. Endocrinology is the scientific study of endocrine organs and hormones (p. 595; Fig. 16.1). 1. Hormones are chemical messengers that are released into the blood and act on target cells over a period of a few seconds to several days. Copyright © 2010 Pearson Education, Inc.

189

190

Text and Media Teacher's Guide to Human Anatomy and Physiology 2. Hormonal targets involve most cells in the body and regulate reproduction, growth and development, electrolyte, water and nutrient balance, cellular metabolism, and energy balance and the mobilization of the body's defenses . 3. Endocrine glands have no ducts and release hormones by diffusion. 4. The endocrine glands include the pituitary, thyroid, parathyroid, adrenal, and pineal glands. 5. Various organs such as the pancreas, the gonads (testes and ovaries) and the placenta contain endocrine tissues. B. Autocrine are local chemical messengers that act on the same cells that secrete them, while paracrine are local chemical messengers that act on neighboring cells rather than the cells that release them (p. 595).

II. Hormones (p. 596-601; Fig. 16.2-16.4) A. Chemistry of hormones (p. 596) 1. Hormones are long-distance chemical signals that are released from cells into the extracellular fluid and regulate the metabolic functions of other cells. . 2. Most hormones are amino acid based, but gonadal and adrenal cortical hormones are cholesterol derived steroids. 3. Eicosanoids, which include leukotrienes and prostaglandins, are derived from arachidonic acid. B. Mechanisms of hormone action (pp. 596-598; Figs. 16.2-16.4) 1. Hormones normally cause changes in membrane permeability or membrane potential, stimulate the synthesis of proteins or regulatory molecules, activate or deactivate enzymes, induce secretory activity or stimulate the mitosis . 2. Water-soluble hormones (all amino acid-based hormones except thyroid hormone) exert their effects through an intracellular second messenger that is activated when a hormone binds to a membrane receptor. 3. Fat-soluble hormones (steroids and thyroid hormones) diffuse into the cell, where they bind to intracellular receptors, migrate to the nucleus, and activate specific target DNA sequences. 4. Second messenger systems, which are activated when a hormone binds to a plasma membrane receptor, activate G proteins inside the cell that alter enzyme activity. 5. Direct gene activation occurs when a hormone binds to an intracellular receptor that activates a specific region of DNA, causing mRNA production and initiating protein synthesis. C. Target Cell Specificity (p. 598) 1. Cells must have specific membranes or intracellular receptors to which hormones can bind. 2. The target cell's response depends on three factors: the blood level of the hormone, the relative number of receptors on the target cell, and the affinity of the receptor for the hormone. 3. Target cells can change their sensitivity to a hormone by changing the number of receptors. D. Half-Life, Onset, and Duration of Hormone Activity (p. 599) 1. The concentration of a hormone reflects its rate of release and the rate of inactivation and elimination from the body. 2. The half-life of a hormone is the time a hormone stays in the blood and is shorter for water-soluble hormones. 3. Target organ response and duration of response vary widely between hormones. Copyright © 2010 Pearson Education, Inc.

Chapter 16

the endocrine system

E. Interaction of Hormones in Target Cells (p. 600) 1. Permissiveness occurs when one hormone cannot exert its full effect without another hormone being present. 2. Synergism occurs when more than one hormone produces the same effects on a target cell and their combined effects are potentiated. 3. Antagonism occurs when one hormone opposes the action of another hormone. F. Control of Hormone Release (p. 600; Fig. 16.4) 1. Most hormone synthesis and release is regulated by negative feedback mechanisms. 2. Stimuli to the endocrine glands can be humoral, neural, or hormonal. 3. Modulation of the nervous system allows hormonal, humoral, and neural stimuli to modify hormone secretion in response to changes in bodily needs.

3. Pituitary and Hypothalamus (pp. 601-608; Figs. 16.5-16.7; Table 16.1) A. The pituitary gland lies in the sella turcica of the skull and is connected to the brain via the infundibulum (p. 601; Fig. 16.5) . B. The pituitary gland has two lobes: the posterior pituitary or neurohypophysis of neural origin and the anterior pituitary or adenohypophysis of glandular origin (pp. 601-603; Fig. 16.5). 1. The hypothalamic-pituitary tract is a neural connection between the hypothalamus and the posterior pituitary that extends through the infundibulum. 2. The hypothalamic-pituitary portal system is a vascular connection between the hypothalamus and anterior pituitary that extends through the infundibulum. C. Hormones of the Anterior Pituitary (pp. 603-605; Figs. 16.6-16.7; Box 16.1) 1. The anterior pituitary produces six hormones, four of which are tropic hormones that regulate the secretion of other hormones and one is a pituitary hormone. a. Proopiomelanocortin (POMC) is a prohormone that can be subdivided into adrenocorticotropic hormone, two natural opiates, and melanocyte-stimulating hormone. B. Growth hormone acts on target cells in the liver, skeletal muscle, bone and other tissues to induce the production of insulin-like growth factors (IGFs). C. Thyroid Stimulating Hormone (TSH) promotes secretion from the thyroid gland. i.e. Adrenocorticotropic hormone (ACTH) promotes the release of corticosteroid hormones from the adrenal cortex. Y. The gonadotropins FSH (follicle stimulating hormone) and LH (luteinizing hormone) regulate the function of the gonads. F. Prolactin stimulates the gonads and promotes milk production in humans. D. Hormones of the Posterior Pituitary and Hypothalamus (pp. 605-608; Box 16.1) 1. The posterior pituitary produces two neurohormones: oxytocin, which promotes uterine contraction and milk flow, and antidiuretic hormone (ADH), which prevents large swings in the balance Water.

4. The thyroid gland (pp. 608-612; Figs. 16.8-16.10; Table 16.2) A. The thyroid consists of hollow follicles with follicular cells that produce thyroglobulin and parafollicular cells that produce calcitonin (p. 608; Fig. 16.8).

Copyright © 2010 Pearson Education, Inc.

191

192

Text and Media Teacher's Guide to Human Anatomy and Physiology B. Thyroid hormone consists of two amino hormones, thyroxine (T4) and triiodothyronine (T3), which act on all cells in the body to increase basal metabolic rate and body heat production. (pp. 609–612; figs. 16.9–16.10; table 16.2). C. Calcitonin is a peptide hormone that lowers blood calcium levels by inhibiting osteoclast activity and stimulating Ca2 uptake and incorporation into bone matrix (pp. 611-612).

V. The Parathyroid Glands (pp. 612-614; Figs. 16.11-16.12) A. The parathyroid glands contain chief cells which secrete parathyroid hormone or parathyroid hormone (pp. 612-613; Figs. 16.11-16.12).

SEEN. The Adrenal Glands (pp. 614-620; Figs. 16.13-16.16; Table 16.3) A. The adrenal glands or adrenal glands consist of two regions: an inner adrenal medulla and an outer adrenal cortex (p. 614; Fig. 16.13). B. The adrenal cortex produces corticosteroids from three different regions: the zona glomerulosa, the zona fasciculata, and the zona reticularis (pp. 614-618; Figs. 16.11-16-15; Box 16.3). 1. Mineralocorticoids, mainly aldosterone, are essential for regulating electrolyte concentrations in extracellular fluids. 2. Aldosterone secretion is regulated by the renin-angiotensin mechanism, by fluctuations in blood sodium and potassium ion concentrations, and by ACTH secretion. 3. Glucocorticoids are released in response to stress from the action of ACTH. 4. Gonadocorticoids are mostly weak androgens that are converted to testosterone and estrogen in tissue cells. C. The adrenal medulla contains chromaffin cells that synthesize epinephrine and norepinephrine (pp. 618-620; Figs. 16.13, 16.16; Table 16.3).

VIII. The Pineal Gland (p. 620) A. The only major secretory product of the pineal gland is melatonin, a hormone derived from serotonin, in a diurnal cycle (p. 620). B. The pineal gland receives indirect information from the visual pathways to determine the time of day and night (p. 620).

VIII. Other Endocrine Glands and Tissues (pp. 620-624; Figs. 16.17-16.18; Box 16.5) A. The pancreas is a mixed gland containing endocrine and exocrine cells (pp. 620-623; Figs. 16.17-16.19 ; Box 16.5). 1. Glucagon is sent to the liver, where it promotes glycogenolysis, gluconeogenesis, and the release of glucose into the blood. 2. Insulin lowers blood sugar levels by increasing the transport of glucose across the membrane into the body's cells. B. The gonads and placenta (p. 623) 1. The ovaries produce estrogen and progesterone. 2. The testicles produce testosterone. 3. The placenta secretes estrogens, progesterone, and human chorionic gonadotropin, which act in the uterus to affect pregnancy. C. Secretion of hormones by other organs (p. 623; Table 16.5) 1. The atria of the heart contain specialized cells that secrete the atrial natriuretic peptide, which reduces blood volume, blood pressure, and blood sodium concentration. Copyright © 2010 Pearson Education, Inc.

Chapter 16

the endocrine system

2. The gastrointestinal tract contains enteroendocrine cells throughout the mucosa that secrete hormones to regulate digestive functions. 3. The kidneys produce erythropoietin, which tells the bone marrow to make red blood cells. 4. The skin produces cholecalciferol, an inactive form of vitamin D3. 5. Adipose tissue produces leptin, which acts on the CNS to induce satiety, and resistin, an insulin antagonist. 6. Osteoblasts in skeletal tissue secrete osteocalcin, a hormone that promotes increased insulin secretion by the pancreas and restricts fat storage by adipocytes. 7. The thymus produces thymopoietin, thymic factor and thymosin, which are essential for the development of T lymphocytes and the immune response.

IX. Developmental aspects of the endocrine system (pp. 624, 626-627) A. Endocrine glands derived from the mesoderm produce steroid hormones; those derived from the ectoderm or endoderm produce proteins, amines, peptides or hormones (p. 624). B. Environmental pollutants have been shown to affect sex hormones, thyroid hormones and glucocorticoids (p. 624). C. Aging can cause changes in the rate of secretion, breakdown, excretion, and sensitivity of target cells (p. 626).

Cross-references For more information on the topics discussed in Chapter 16, see the chapters listed below. 1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th 11th 12th 13th

14

fifteen.

Chapter 1: Negative Comments Chapter 2: Steroids; Amino Acids Chapter 3: General Cell Function Chapter 4: Endocrine Glands Chapter 6: Bone Homeostasis; Epiphyseal Plate Chapter 11: Enkephalin and Beta-Endorphin; Noradrenaline and Adrenaline Chapter 12: Hypothalamus Chapter 14: Noradrenaline and Adrenaline Chapter 19: Hepatic Portal System; control of blood pressure; Atrial natriuretic peptide and regulation of blood pressure Chapter 21: Effects of thymus hormones Chapter 23: Gastrin and secretin (hormones of the digestive system) Chapter 24: Effects of insulin and glucagon; Hormonal function related to general body metabolism Chapter 25: Function of antidiuretic hormone; Effects of Aldosterone on Kidney Tissues; renin-angiotensin mechanism of blood pressure regulation; Role of Atrial Natriuretic Factor and Fluid and Electrolyte Balance Chapter 26: Function of Antidiuretic Hormone; Effects of Aldosterone on Kidney Tissues; renin-angiotensin mechanism of blood pressure regulation; role of parathyroid hormone and calcium balance in development; role of atrial natriuretic peptide and fluid and electrolyte balance; Role of Estrogens and Glucocorticoids in Fluid and Electrolyte Balance Chapter 27: Role of Gonadotropins; testosterone production; Role of FSH and LH in Reproduction; role of relaxin and inhibin in reproduction; ovarian physiology; Brain Testicular Axis Copyright © 2010 Pearson Education, Inc.

193

194

Text and media Manual of human anatomy and physiology 16. Chapter 28: Stimulating milk production by the mammary gland (due to prolactin secretion); results from the release of oxytocin and prolactin; role of parathyroid hormone and calcium balance in development; Functions of human placental lactogen and human chorionthyrotropin; prostaglandins and reproductive physiology; role of relaxin

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 27: Functional anatomy of the endocrine gland Exercise 28: Hormone action PhysioEx™ 8.0 Exercise 28B: Physiology of the endocrine system: computer simulation 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 27: Functional anatomy of the endocrine glands Exercise 28: Hormone action PhysioEx™ 8.0 Exercise 28B: Physiology of the endocrine system: computer simulation

Teaching Tips 1. A flowchart structure is an ideal way to consolidate a large volume of complex material into a compact package. Suggest that the class map out the entire endocrine system on a single large piece of brown paper in the form of a flowchart. Let's start at the top with the pituitary gland and follow each hormone's path to its target tissue. When students can see the whole picture on a single page, they will easily master the concepts of endocrine function. 2. Emphasize that small amounts of the hormone are enough to produce a fairly large effect in the body. 3. Students are often confused as to the actual location of neuropituitary hormone production. Point out that the hypothalamus is the primary site of production and that the axons of hormone-producing neurons end in the neuropituitary (where neurohormones are released). 4. Emphasize the importance of receptor regulation in non-insulin dependent (type 2) diabetes. 5. The Mechanism of Hormone Action is an ideal way to ask the class some critical thinking questions. Ask the class, "If you know the properties of steroids and proteins, how should these hormones be transported in the blood and what mechanism (second messenger or intracellular receptor) requires what type of hormone?" 6. Some hormones are also neurotransmitters. Emphasize to students that there is no difference between a hormone and a neurotransmitter, using an example such as norepinephrine; the difference lies in the source of the chemical. 7. Use the root word definitions to emphasize the function of the parts of the pituitary gland: adeno-gland; neuronervous. 8. State the advantage of a portal system (eg the digestive system) for the direct release of releasing and inhibitor hormones from the hypothalamus into the pituitary gland. 9. If possible, provide pairs of antagonistic hormones (glucagon-insulin, calcitonin-parathyroid hormone) and direct control versus control by regulatory factors (hormones).

Copyright © 2010 Pearson Education, Inc.

Chapter 16

the endocrine system

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Use a torso model and/or stuffed animal model to show the endocrine glands. 3. Use photos to demonstrate various endocrine disorders such as goiter, gigantism, cretinism, acromegaly, etc.

Critical Thinking/Discussion Points 1. Discuss how the negative feedback mechanism controls hormonal activity and yet allows hypo- and hypersecretory disorders to occur. 2. Examine why the pancreas, ovaries, testicles, thymus, digestive organs, placenta, kidneys and skin are considered endocrine functions. Relate the endocrine functions to their non-endocrine functions. 3. Discuss the role of the endocrine system in stress and stress responses. 4. Explain the basis for the fact that nervous control is rapid but short-lived, while hormonal control is slow onset but long-lasting. How would the body's function change if the rate of hormonal breakdown increased? Reduced? 5. Why do protein-based and steroid-based hormones use second messenger and intracellular receptor mechanisms of action, respectively, based on their chemical properties? 6. Examine the consequences of increasing the number of receptors, decreasing the number of receptors, and increasing or decreasing hormone release rates. 7. Present the following scenario to the students: you have just finished a large meal and are relaxing when you are suddenly threatened by a thief. Ask students to explain what happens in the body from an autonomic and hormonal point of view. Encourage them to think logically and be as complete as possible.

Library Research Topics 1. Examine the role of hormones in the treatment of non-hormonal disorders. 2. Investigate the hereditary aspect of certain hormones (e.g. diabetes mellitus and certain thyroid disorders). 3. Examine the role of prostaglandins in treating homeostatic imbalances. 4. Identify the different circadian rhythms of the body. 5. Research methods for determining the level of blood hormones. 6. Define diabetes insipidus. How is this type of diabetes related to insulin-related diabetes? 7. Research the various diseases of the pituitary gland and discuss what physical effects result from them.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all chapter-specific online media resources for Chapter 16. Copyright © 2010 Pearson Education, Inc. All rights reserved.

195

196

Text and media guide to human anatomy and physiology in one convenient place, with eBook links to each section of the book. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 16.1 The Endocrine System: An Overview (pp. 595-596) Artist Labeling: Location of Selected Endocrine Organs in the Body (Fig. 16.1, p. 595) Physiology Interactive® Set of 10: Endocrine System Orientation Physiology Interactive ® 10 -Kit: Overview of the Endocrine System Section 16.2 Hormones (pp. 596-601) Physiology® 10-Interactive Kit: Hormone Biochemistry, Secretion and Transport Physiology® 10-Interactive Kit: The Effect of Hormones on Cells Section 16.3 The Pituitary and Hypothalamus ( pp. 601-608) MP3 Tutor Session: Regulation of the Hypothalamus Interactive Physiology® 10-System Suite: The Hypothalamic-Pituitary Axis Case Study: Endocrine System Section 16.4 The Thyroid Gland (pp. 608-612 ) Section 16.5 The Parathyroid Glands (pp. 612–614) Section 16.6 The adrenal glands (pp. 614–620) Set of 10 interactive physiology systems: Stress response Section 16.7 The gland Pineal (p. 620) Section 16.8 Other endocrine glands and tissues (pp. 620–624) Fal lStudy: Diabetes mellitus Section 16.9 Developmental aspects of the endocrine system (p. 624, 626–627) Chapter Summary Memory Game: Endocrine Structure and Function Memory Game: Regulatory Processes Associated with the Endocrine System PhysioEx™ 8.0: Physiology of the Endocrine System Crossword 16.1 Crossword 16.2 Web Links Chapter Quizzes Artistic Labeling Quiz Matching Quiz Multiple Choice Quiz True-False -Quiz Practice Quiz Chapter Tools Study Histology Atlas myeBook Flashcards Glossary

Copyright © 2010 Pearson Education, Inc.

Chapter 16

the endocrine system

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Slide 1. Cable Gland Type (CBS). Provides scanning electron micrographs of the organization, zona glomerulosa, zona fasciculata, and zona reticularis.

Video 1. Diagnosis and treatment of diabetes (FHS; 22 min, 1998). Explore the manifestation, diagnostic tests, treatment, and biochemistry of diabetes mellitus. 2. The Endocrine System: Molecular Messengers, Chemical Control (IM; 30 min, 2007). This DVD examines hormones, target cell hormone receptors and feedback mechanisms in the endocrine system. It also deals with the hormone-producing organs such as the thymus, pancreas, ovaries, and kidneys. 3. Hormonal control (ESF; 10 min.). This video discusses the role hormones play in maintaining homeostasis. The show illustrates how hormone production stimulates responses and how hormone production is in turn controlled. 4. Hormonally Yours (FHS; 50 min, 1999). From the Body Chemistry: Understanding Hormones series, this show explores the role of hormones in gender and sexuality. 5. The paradise of hormones? (ESF; 50 mins, 1999). Part of the Body Chemistry: Understanding Hormones series, this program attempts to answer questions about the role of hormones in maintaining youthful vitality. 6. Hormonal Hell (FHS; 50 min., 1999). From the Body Chemistry: Understanding Hormones series, this program explores how hormones affect different stages of life. 7. Hormones: messengers (FHS; 27 min., 1984). This program from The Living Body series covers a variety of bodily processes that are controlled and coordinated by hormones. 8. Selected effects of hormones and other chemical messengers (BC; 10 min., 1994). This video offers an examination of the mode of action of selected hormones through three experiments: the effect of pituitary hormones on the frog ovary, the effect of hyperinsulinism on a small fish, and the effect of epinephrine on the heart.

A.D.A.M.® Interactive Anatomy® 4.0 software (see full list on page 9 of this manual). A.D.A.M.® MediaPro (see page 9 of this manual for a complete list). A.D.A.M.® Anatomy Practice (see page 87 of this manual for a complete list). Interactive set of 10 Physiology® systems: Endocrine System (BC; Win/Mac). It includes the identification of the major glands and their target tissues, as well as the classification and function of hormones. 5. Practice Anatomy Lab™ 2.0: Human cadaver, anatomical models, histology, cat, fetal pig (see full list on page 9 of this manual). 6. The Ultimate Human Body, version 2.2 (see page 9 of this manual for a complete list).

1. 2. 3. 4.

Copyright © 2010 Pearson Education, Inc.

197

198

Text and media guide to human anatomy and physiology

Material to improve the lesson Thumbnails of all illustrations in Chapter 16 can be found in Appendix B.

Instructor Index Slide/Resource DVD Figure 16.1 Figure 16.2 Figure Figure Figure Figure

16,3 16,4 16,5 16,6

Figure Figure Figure Figure Figure

16,7 16,8 16,9 16,10 16,11 16,12

Figure 16.13 Figure 16.14 Figure Figure Figure Figure Table Table Table Table Table

16,15 16,16 16,17 16,18

16,1 16,2 16,3 16,4 16,5

A Closer Look Making Connections

Location of selected endocrine organs of the body. Cyclic AMP second messenger mechanism of water-soluble hormones. Mechanism of direct gene activation of fat-soluble hormones. Three ways of stimulating the endocrine glands. Relationship between the pituitary and hypothalamus. Metabolism and growth-promoting effects of growth hormone (GH). Regulation of thyroid hormone secretion. Thyroid. Synthesis of thyroid hormones. thyroid disorders. The parathyroid glands. Effects of parathyroid hormone on bone, kidney and intestine. Microscopic structure of the adrenal gland. Main mechanisms controlling the release of aldosterone from the adrenal cortex. The effects of excess glucocorticoids. Stress and Adrenal Gland. Photomicrograph of pancreatic tissue with differential staining. Regulation of blood sugar levels by insulin and glucagon from the pancreas. Pituitary hormones: summary of regulation and effects Main effects of thyroid hormones (T4 and T3) on the body Adrenal gland hormones: summary of regulation and effects Symptoms of insulin deficiency (diabetes mellitus) Selected examples of hormones produced by organs other than major endocrine organs Sweet Revenge: Taming the Monster DM? Homeostatic interrelationships between the endocrine system and other body systems

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 15. A hormone is a chemical messenger that is released into the blood to be transported throughout the body. (p. 595) 16. Binding of a hormone to intracellular receptors would lead to the longest lasting response since extracellular receptors activate second messenger systems which are rapidly degraded by intracellular enzymes. (p. 597)

Copyright © 2010 Pearson Education, Inc.

Chapter 16

the endocrine system

17. a. The anterior pituitary is connected to the hypothalamus by a rod of tissue, the infundibulum (p. 601); the pineal gland depends on the roof of the third ventricle (p. 620); the pancreas is dorsal to the stomach and partially retroperitoneal (pp. 620-621); the ovaries are retroperitoneal organs within the female pelvic cavity (p. 623); the testes are contained in an extra-abdominal pouch called the scrotum (p. 623); and the adrenal glands are above the kidneys. (p. 614) b. The anterior pituitary produces six hormones: growth hormone, thyroid-stimulating hormone, adrenocorticotropic hormone, follicle-stimulating hormone, luteinizing hormone, and prolactin (pp. 606-607); the pineal gland produces melatonin (p. 620); the pancreas produces glucagon and insulin and small amounts of somatostatin (p. 621); the ovaries produce estrogen and progesterone (p. 623); the testicles produce androgens, mainly testosterone (p. 623); and the adrenal glands produce cortical mineralocorticoid, glucocorticoid, and gonadocorticoid hormones, as well as the adrenal medullary hormones epinephrine and norepinephrine. (pp. 614-615) 18. The endocrine regions important for the stress response are the adrenal medulla and the adrenal cortex. The adrenal medulla produces hormones that mimic the action of neurotransmitters from the sympathetic part of the autonomic nervous system. The adrenal cortex produces the glucocorticoids (and mineralocorticoids) that are important for the stress response. Hormones from the adrenal medulla act in the alarm reaction; Hormones of the adrenal cortex in the resistance stage. (pp. 614, 616, 619) 19. Hormone release from the anterior pituitary is controlled by hypothalamic-releasing hormones (and hypothalamic inhibitors). (p. 603) 20. The posterior pituitary consists largely of axons from hypothalamic neurons, which store and secrete antidiuretic hormone (ADH) and oxytocin synthesized by hypothalamic neurons. (p. 605) 21. Deficiency of iodine (necessary to produce functional T3 and T4) causes colloidal or endemic goiter. (p. 611) 22. Problems that older people may have due to decreased hormone production include the following: a. Chemical or borderline diabetes c. increased body fat b. reduced basal metabolic rate d. Osteoporosis (pp. 626-627) 23. Specialized heart muscle cells produce atrial natriuretic peptide that promotes sodium and water loss in the kidneys. (p. 624) Neurons in the posterior pituitary secrete oxytocin, which promotes contraction of smooth muscle in the uterus, or antidiuretic hormone, which increases water reabsorption in the kidneys. (pp. 605-606) In addition, neurosecretory cells in the adrenal medulla secrete epinephrine and norepinephrine. (p. 619) 24. High levels of stress may increase cortisol secretion and contribute to loss of memory or cognitive function. Lower aldosterone levels can lead to a slight increase in plasma K+. A relative lack of estrogen can lead to atherosclerosis. A lack of estrogen, but a small change in PTH, can also contribute to osteoporosis. In addition, with age, glucose tolerance decreases, leading to an increase in blood sugar, and thyroid fibrosis leads to a decrease in basal metabolic rate. (pp. 616 and 617)

Critical Thinking Questions and Clinical Application 1. It is not uncommon to find them in other regions of the neck or even in the chest. Adjacent neck regions should be checked first. (p. 612) 2. Insulin should be administered since the symptoms indicate diabetic shock. (p. 622) Copyright © 2010 Pearson Education, Inc.

199

200

Text and Media Human Anatomy and Physiology Teacher's Guide 3. The hormone that is secreted in excess is growth hormone. Clutter is gigantism. The enlarged pituitary gland puts pressure on the optic chiasm (or other parts of the visual pathway). (p. 603) 4. a. A likely possibility is that Sean has Addison's disease, a hyposecretory disorder of the adrenal cortex that affects the secretion of glucocorticoids and mineralocorticoids. The main mineralocorticoid, aldosterone, is responsible for promoting Na+ uptake along with K+ secretion in the nephron. The resulting hyposecretion of aldosterone would account for its elevated plasma K+. B. An ACTH stimulation test allows the physician to distinguish between pituitary deficiency of ACTH secretion and adrenal sensitivity or insufficiency. C. If ACTH is not causing a normal rise in cortisol, then the problem has adrenal origins and is likely Addison's disease. i.e. If ACTH causes an increase in cortisol secretion, there is likely a problem in the anterior pituitary gland, such as: B. a tumor or malignancy. (p. 618) 5. Mr. Proulx has Cushing's disease caused by high levels of prednisone. Its general malaise is due to muscle weakness and possible hyperglycemia, its swelling to water and salt retention, and the drug's anti-inflammatory effects play a role in suppressing defense mechanisms related to the immune system, thereby increasing your susceptibility to colds. (pages 617 and 618)

Suggested Reading Birnbaum, Morris J. "Dialogue between muscle and fat." Nature 409 (6821) (February 2001): 672-673. Mathis, D., et al. "B cell death during progression to diabetes". Nature 414 (6865) (2001 December): 792-799. Rabinovich, Alex. "Autoimmune diabetes mellitus". Science and Medicine 7(3) (May/June 2002): 18-27. Ralph, Janet. "Can Infant Feeding Lead to Diabetes?" Science News 159(7) (February 2001): 111. Saltiel, A.R. and CR. barge. "Insulin signaling and regulation of glucose and lipid metabolism". Nature 414 (6865) (December 2001): 799-807. Leicht, Simon H. "Cardiovascular steroidogenesis." Science and Medicine 8(1) (2002 Jan/Feb): 36–45.

Copyright © 2010 Pearson Education, Inc.

Sangre

Summary of Objectives: Composition and Functions of Blood 1. Describe the composition and physical properties of whole blood. Explain why it is classified as connective tissue. 2. Name eight functions of the blood. Blood plasma 3. Discuss the composition and functions of plasma. Shaped elements 4. Describe the structure, function and production of red blood cells. 5. Describe the chemical composition of hemoglobin. 6. Give examples of disorders caused by red blood cell abnormalities. Explain what is wrong with each disorder. 7. Name the classes, structural features and functions of leukocytes. 8. Describe how leukocytes are produced. 9. Give examples of white blood cell disorders and what is wrong with each disorder.

17

10. Describe the structure and function of platelets. Hemostasis 11. Describe the processes of hemostasis. List the factors that limit clot formation and prevent unwanted clot formation. 12. Give examples of hemostatic disorders. State the cause of each condition. Transfusion and blood substitution 13. Describe the ABO and Rh blood groups. Explain the basis of transfusion reactions. 14. Describe the fluids used to replenish blood volume and the circumstances of their use. Diagnostic blood tests 15. Explain the diagnostic importance of blood tests. Developmental aspects of the blood 16. Describe the changes in the sites of blood production and the type of hemoglobin produced after birth. 17. Name some blood disorders that become more common as you get older.

Suggested Lesson Plan I. Overview: Composition and Functions of Blood (pp. 635-636; Fig. 17.1) A. Constituents (p. 635; Fig. 17.1) 1. Blood is a specialized connective tissue composed of living cells known as Elements are called suspended in a non-living liquid matrix, blood plasma. 2. The centrifuged blood is separated into three layers: erythrocytes, buffy coat and plasma. 3. Blood hematocrit represents the percentage of erythrocytes in whole blood.

201 Copyright © 2010 Pearson Education, Inc.

202

Text and Media Teacher's Guide to Human Anatomy and Physiology B. Physical Properties and Volumes (p. 635) 1. Blood is a slightly basic liquid (pH 7.35–7.45) which, by virtue of its presence, has a higher density and viscosity than water has of formed elements. 2. Normal blood volume is 5-6 liters in males and 4-5 liters in females. C. Functions (pp. 635-636) 1. Blood is the medium for the transport of oxygen and nutrients, the transport of metabolic waste to elimination sites, and the distribution of hormones. 2. Blood helps regulate body temperature, pH of body fluids, and fluid volume in fluid compartments. 3. Blood protects against excessive blood loss through the clotting mechanism and against infection through the immune system.

II. Blood plasma (p. 636; Table 17.1) A. Blood plasma consists primarily of water (90%) and solutes, including nutrients, gases, hormones, waste products, products of cell activity, ions and proteins (p. 636; Table 17.1) . Table 17.1). B. Plasma proteins make up 8% of plasma solutes, mainly albumin, which act as transporters (p. 636).

3. Shape Elements (pp. 637-649; Fig. 17.2-17.12; Tab. 17.2) A. Erythrocytes (pp. 637-643; Fig. 17.2-17.8) 1. Erythrocytes or red blood cells are small, biconcave shaped cells . They lack nuclei and most organelles, and contain mostly hemoglobin. a. Hemoglobin is an oxygen-fixing pigment responsible for carrying most of the oxygen in the blood. B. Hemoglobin consists of the protein globin bound to the red pigment heme. 2. Production of erythrocytes a. Hematopoiesis, or the formation of blood cells, takes place in the red bone marrow. B. Erythropoiesis, the formation of red blood cells, begins when a myeloid stem cell transforms into a proerythroblast, which develops into mature red blood cells. C. Red blood cell production is controlled by the hormone erythropoietin. i.e. The nutritional requirements for the formation of erythrocytes include iron, vitamin B12 and folic acid, as well as proteins, lipids and carbohydrates. Y. Blood cells have a short lifespan due to the lack of nuclei and organelles; The destruction of dead or dying blood cells is carried out by macrophages. 3. Red blood cell disorders a. Anemia is characterized by a lack of red blood cells. B. Polycythemia is characterized by an abnormal excess of red blood cells. B. Leukocytes (pp. 643-648; Figs. 17.9-17.11; Table 17.2) 1. Leukocytes or white blood cells are the only elements formed that are complete cells and make up less than 1% of the total blood volume. 2. Leukocytes are essential to our defense against disease. 3. Granulocytes are a major group of leukocytes characterized as large cells with lobulated nuclei and visibly stained granules; all are phagocytic. a. Neutrophils are the most numerous type of leukocytes. They are chemically attracted to sites of inflammation and are active scavenger cells. B. Eosinophils are relatively rare and attack parasitic worms.

Copyright © 2010 Pearson Education, Inc.

Chapter 17

Sangre

C. Basophils are the least numerous white blood cells and release histamine to promote inflammation. 4. Agranulocytes are an important group of lymphocytes that lack visible staining granules. a. T lymphocytes directly attack tumor cells and those infected with viruses; B lymphocytes produce antibody cells. B. Monocytes become macrophages and activate T-lymphocytes 5. Leukocyte production and lifespan a. Leucopoiesis, the formation of white blood cells, is regulated by the production of interleukins and colony stimulating factors (CSFs). B. Leucopoiesis involves the differentiation of stem cells along two pathways: lymphoid and myeloid stem cells. 6. Leukocyte Diseases a. Leukopenia is an abnormally low white blood cell count. B. Leukemias are clones of a single white blood cell that are unspecialized and divide uncontrollably. C. Infectious mononucleosis is a disease caused by the Epstein-Barr virus. C. Platelets (pp. 648-649; Fig. 17.12) 1. Platelets are not whole cells but fragments of large cells called megakaryocytes. 2. Platelets are critical to the clotting process as they form the temporary blockage when a blood vessel ruptures. 3. Platelet formation involves repeated mitosis of megakaryocytes without cytokinesis.

4. Hemostasis (pp. 649-654; Figs. 17.13-17.14; Table 17.3) A. Rupture of a blood vessel stimulates hemostasis, a rapid, localized response designed to reduce clotting blood loss (p. 649). B. Vascular spasm is the immediate vasoconstrictive response to blood vessel injury (p. 649). C. Formation of Platelet Plugs (pp. 649-650; Fig. 17.13) 1. When the endothelium is damaged, the platelets become sticky and pointed, sticking to each other and to the wall of the damaged vessel. 2. Once attached, other platelets are attracted to the site of injury, activating a positive feedback loop for clot formation. D. Coagulation or blood clotting is a multi-step process in which blood goes from a liquid to a gel (pp. 650-652; Figs. 17.13-17.14; Table 17.3). 1. Factors that promote clotting are called clotting factors or procoagulants; those that inhibit clot formation are called anticoagulants. 2. The coagulation process consists of three phases: formation of prothrombin activator, conversion of prothrombin to thrombin and formation of the fibrin network from fibrinogen in plasma. a. The intrinsic coagulation pathway is so named because all the necessary factors are present in the blood. It is a slower clotting pathway and can be triggered by negatively charged surfaces such as activated platelets, collagen or glass. B. The extrinsic signaling pathway is initiated by an endothelium-derived protein factor called tissue factor (TF) or Factor III and can occur very rapidly.

Copyright © 2010 Pearson Education, Inc.

203

204

Text and Media Teacher's Guide to Human Anatomy and Physiology E. Clot retraction and repair (p. 652) 1. Clot retraction is a process in which contractile proteins within platelets contract and pull on the strands of adjacent fibrin, causing the Plasma squeezed out of the clot will clot. and bandage the edges of the damaged tissue. 2. Repair is stimulated by platelet growth factor (PDGF). F. Fibrinolysis removes unnecessary clots by the action of the enzyme plasmin, which digests fibrin (p. 652). G. Factors that Limit Growth or Clot Formation (pp. 652-653) 1. Fast moving blood disperses clotting factors before they can initiate a coagulation cascade. 2. Thrombin that does not bind fibrin is inactivated by antithrombin III and protein C and by heparin. H. Disorders of Hemostasis (pp. 653-654) 1. Thromboembolic disorders result from conditions that cause undesirable clotting, such as: B. stiff endothelial vessels, slow blood flow or blood congestion. 2. Disseminated intravascular coagulation is a condition that results in generalized coagulation in intact vessels and can occur as a complication of pregnancy, sepsis, or incompatible blood transfusions. 3. Bleeding disorders arise from abnormalities that prevent normal clot formation, such as: B. Lack of circulating platelets, lack of procoagulant synthesis or hemophilia.

V. Blood transfusion and substitution (pp. 654-657; Fig. 17.15; Table 17.4) A. Whole blood transfusions are routine when blood loss is significant or when thrombocytopenia is being treated (pp. 654-656; Fig. 17.15); Table 17.4). 1. People have different blood types based on the specific antigens on the membranes of red blood cells. 2. ABO blood groups are based on the presence or absence of two types of agglutinogens. 3. Preformed antibodies (agglutinins) are present in the blood plasma and do not correspond to the person's blood. 4. Rh factor is a group of RBC antigens that are either present in Rh blood or not present in Rh blood. 5. A transfusion reaction occurs when the infused donor's blood type is attacked by agglutinins in the recipient's blood plasma, resulting in agglutination and hemolysis of the donor cells. B. Blood volume and plasma expanders are administered at extremely low blood volume (pp. 656-657).

SEEN. Diagnostic Blood Tests (p. 657) A. Changes in some visual properties of the blood can indicate diseases such as anemia, heart disease and diabetes (p. 657). B. White blood cell differential counts are used to detect differences in the relative amounts of certain types of blood cells (p. 657). C. The prothrombin time, which measures the amount of prothrombin in the blood, and the platelet count assess the state of the hemostatic system (p. 657). D. SMAC, SMA12-60 and complete blood count (CBC) provide comprehensive values ​​of blood condition (p. 657).

Copyright © 2010 Pearson Education, Inc.

Chapter 17

Sangre

VIII. Aspects of blood development (p. 657) A. Before birth, formation of blood cells occurs in the yolk sac, liver and spleen of the fetus, but by the seventh month the red bone marrow is the main site of hematopoiesis (p. 657) . . B. Fetal blood cells produce hemoglobin-F, which has a higher affinity for oxygen than adult hemoglobin, hemoglobin-A (p. 657).

Cross-references For more information on the topics covered in Chapter 17, see the chapters listed below. 1st 2nd 3rd 4th 5th 6th 7th

8. 9. 10. 11. 12.

Chapter 3: Diffusion; osmosis Chapter 4: Tissue repair Chapter 6: Hematopoietic tissue Chapter 18: Role of the heart in blood supply Chapter 19: Vasoconstriction as a blood flow control mechanism; Summary of Arteries, Capillaries, and Veins Chapter 20: Role of the Spleen in Removing Old Red Blood Cells; Macrophages Chapter 21: Role of Granulocytes in Non-Specific Resistance; role of lymphocytes (T and B cells) in specific immune response; role of monocytes (macrophages) in the immune response; SUPPORT; antigen-antibody interaction; diapedesis; Chemotaxis Chapter 22: Gas exchange between blood, lungs and tissues; Respiratory Gas Transport Chapter 23: Vitamin B12 Absorption; Vitamin K production in the colon Chapter 24: Role of blood in regulating body temperature Chapter 25: Erythropoietin related to kidney function; plasma filtration chapter 26: control of water and ion balance; acid-base balance

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 29: Blood PhysioEx™ 8.0 Exercise 29B: Blood Analysis: Computer Simulation 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 29: Blood PhysioEx™ 8.0 Exercise 29B: Blood Analysis: Computer Simulation

Teaching Tips 1. Emphasize that hematocrit is an indirect measure of the blood's O2-carrying capacity. More red blood cells means more O2 carried by the same amount of blood. 2. Emphasize that simple diffusional gradients cause the charging and discharging of respiratory gases and other substances. It can be helpful to ask students specific questions about diffusion of respiratory gases during the lesson to ensure the class understands this concept. 3. As an interesting point, mention that well-oxygenated blood is bright red; normal deoxygenated blood (at the tissue level) is dark red; and that hemoglobin turns blue under hypoxic conditions. Copyright © 2010 Pearson Education, Inc.

205

206

Text and Media Human Anatomy and Physiology Teacher Guide 4. Take some time to explore the feedback loop of erythropoiesis. This is a typical negative feedback mechanism that allows critical thought processes to be applied. 5. Mention that serum is essentially plasma with no clotting proteins. 6. Point out the delicate balance between clotting and preventing unwanted clotting. We want to make sure we stop bleeding, but at the same time prevent clots from forming in intact blood vessels. 7. Emphasize that ABO incompatibility does not require sensitization by prior blood transfusion, while Rh incompatibility does. 8. Regulation of hemostasis is often difficult for students. Areas to be clarified include: the continued presence of various coagulation factors circulating in the blood in an inactive form; the production of activating and inhibitory stimuli; and the importance of rapid blood flow in preventing spontaneous clot formation. 9. Students often have difficulty understanding the terms blood antigens and antibodies and how they relate to the terms agglutinogens and agglutinins. Emphasize the position in the blood of each.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. View the equipment used to determine hematocrit, sedimentation rate and cell count. Describe how these tests are performed and what information they provide. Perform a hematocrit test so students can see the difference in plasma volume and elements formed. 3. Provide blood group sera and ask students to type their own blood. All lancets and disposables should be placed in a disposable autoclave bag immediately after use, and used slides should be placed in freshly prepared 10% bleach solution and soaked for at least two hours. Both the autoclave bag and the slides should be autoclaved for 15 minutes. at 121˚C, 15 lbs. Pressure to ensure sterility. After autoclaving, the autoclave bag can be disposed of in any disposable container; Glass slides can be washed with laboratory detergent and prepared again for use. 4. Provide a centrifuged animal blood sample for students to examine the plasma for consistency, texture, and color. Have pH paper ready so students can determine their pH. Use this activity as a guide for a discussion of the composition and importance of plasma. 5. Use templates to display blood cells. 6. Prepare a stained blood smear to show as many types of white blood cells as possible.

Critical Thinking/Topics for Discussion 1. Discuss the fears and facts surrounding blood donation, transfusions and AIDS. 2. Investigate problems associated with injecting drug use (e.g., hepatitis, AIDS, tissue necrosis, and other blood-related diseases). 3. Discuss the autologous transfusion procedure. 4. Discuss why gamma globulin injections are painful. 5. Why do red blood cells have no nucleus? Why is this an advantage? 6. How can you explain that ABO blood group incompatibility causes a transfusion reaction in the first transfusion, while Rh incompatibility causes a problem in the second transfusion? Copyright © 2010 Pearson Education, Inc.

Chapter 17

Sangre

Library Research Topics 1st 2nd 3rd 4th 5th 6th 7th

8. 9.

Research blood disorders linked to injecting street drug use. Examine the role of blood in the AIDS epidemic. Investigate hereditary blood disorders. Discover blood antigens beyond A, B and Rh. Examine the different blood immunoglobulins, their functions and how they are produced (ie the stimulus required). Review the various uses of donated blood (i.e. packed red cells, platelets, etc.). Find out which diseases are blood borne and why these diseases are becoming more prevalent. Why is the careful handling of blood in the clinic crucial? What advances have been made that could make it possible to use blood stem cells as a source of stem cells for other cell lines? Examine cord blood bank expiry and frequency.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all chapter-specific online media resources for Chapter 17 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Learning objectives Section 17.1 Overview: Composition and functions of blood (pp. 635-636) Section 17.2 Blood plasma (p. 636) Memory game: Blood cells Section 17.3 Shaped elements (pp. 637-649) MP3 Tutor Session: Hemoglobin: Function and Impact Physiology® 10-System Interactive Game: Respiratory System: Gas Transport Memory Game: Identification of Form Elements of Blood Case Study: Iron Deficiency Anemia Case Study: Sickle Cell Anemia Section 17.4 Hemostasis (pp. 649-654) Section 17.5 Blood Transfusion and Replacement (pp. 654-657) Section 17.6 Diagnostic blood tests (p. 657) Section 17.7 Aspects of blood development (p. 657) Chapter summary Crossword 17.1 Crossword 17.2 Crossword 17.3 Web links

Copyright © 2010 Pearson Education, Inc.

207

208

Text and Media Human Anatomy and Physiology Teacher's Guide Chapter Test Art Labeling Test Matching Test Multiple Choice Test True/False Test Chapter Practice Test Learning Tools Histology Atlas myeBook Flashcards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Slides 1. Human blood smear, Wright's stain (FSE). Slide clearly distinguishes between erythrocytes and leukocytes.

Video 1. Hemorrhage and Coagulation (FHS; 31 min, 2000). Examines the body's coagulation mechanism using case studies. 2. Blood (FHS; 20 min, 1995). This video from The New Living Body series explains blood and circulation through the story of a person suffering from sickle cell anemia. 3. Blood is Life (ESF; 45 min., 1995). Award-winning video introducing human blood. 4. Blood disorders: questions and answers (ESF; 24 min, 1999). Find out about treatments for multiple myeloma and chronic lymphocytic leukemia.

Software 1. Blood and Immunity (EC, LP; Win/Mac). Teaches blood components, blood groups and blood processes. Contains information about HIV. 2. Blood and Circulatory System NEO/LAB (FSE; Win/Mac). It offers interactive exercises on blood types, morphology and genetics. 3. Interactive set of 10 Physiology® systems: cardiovascular system (BC; Win/Mac). Interactive software that explores the physiology of the cardiovascular system. 4. Practice Anatomy Lab™ 2.0: Histology (see full list on page 9 of this manual).

Material to improve the lesson Thumbnails of all illustrations in Chapter 17 can be found in Appendix B.

Copyright © 2010 Pearson Education, Inc.

Chapter 17

Sangre

Figure 17.1 Figure 17.2 Figure 17.3 Figure 17.4 Figure 17.5 Figure 17.6 Figure 17.7 Figure 17.8 Figure 17.9 Figure 17.10 Figure 17.11 Figure 17.12 Figure 17.13 Figure 17.14 Figure 17.15 Figure 17.16 Table 17.2.1

The main components of whole blood. Photomicrograph of a human blood smear stained with Wright's stain. Structure of the erythrocytes. Structure of Hemoglobin. Erythropoiesis: Formation of red blood cells. Mechanism of erythropoietin to regulate erythropoiesis. Red blood cell life cycle. Sickle cell anemia. Types and relative percentages of leukocytes in normal blood. Leukocytes Leukocyte formation. platelet genesis. Hemostasis Events. The intrinsic and extrinsic pathways of blood coagulation (clotting). Scanning electron micrograph of red blood cells encased in a fibrin mesh. Blood types from ABO blood types. Summary of the plasma composition of blood-forming elements Blood clotting factors (procoagulants) ABO blood groups

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 11. a. The elements formed are living blood cells. The main categories of elements formed are erythrocytes, leukocytes and platelets. B. Few of the elements formed are leukocytes. C. The buffy coat in a hematocrit tube contains white blood cells and platelets. (p. 635) 12. Hemoglobin consists of the protein globin bound to the dye heme. Each molecule contains four polypeptide chains (globins) and four heme groups, each with an iron atom at its center. Its job is to bind oxygen to each iron atom. When oxygen becomes charged (bound to hemoglobin), hemoglobin turns bright red. When oxygen is released from iron, hemoglobin turns dark red. (p. 638) 13. With a high hematocrit, you would expect the hemoglobin to be high since hematocrit is the percentage of blood that is made up of red blood cells. (p. 635) 14. Besides carbohydrates for energy and amino acids needed for protein synthesis, nutrients needed for erythropoiesis are iron and certain B vitamins (p. 640) 15. a. In the process of erythropoiesis, a stem cell transforms into a proerythroblast, giving rise to early and late erythroblasts, normoblasts, and reticulocytes. B. The immature cell type released into the circulation is the reticulocyte. C. The reticulocyte differs from a mature erythrocyte in that it still contains some coarse ER. (p. 639) Copyright © 2010 Pearson Education, Inc.

209

210

Text and Media Instructor's Guide to Human Anatomy and Physiology 16. Physiological attributes that contribute to the function of white blood cells in the body include the ability to move through amoeboid action, the display of positive chemotaxis, allowing areas with identify damaged tissue, diapedesis (movement through capillary walls) and the ability to participate in phagocytosis. (p. 643) 17. a. In a severe infection, the white blood cell count would be closer to 15,000 white blood cells/mm3 of blood. B. This condition is called leukocytosis. (p. 643) 18. a. Platelets appear as small discoid fragments of large multinucleated cells called megakaryocytes. They are essential to the clotting process and work together to form a temporary plug to prevent blood loss. B. Platelets should not be referred to as "cells" since they are just fragments of cells. (p. 648) 19. a. Hemostasis is literally "stagnant blood" because it refers to clotted blood. It includes the steps that prevent blood loss from the blood vessels. (p. 649) b. The three main steps in coagulation involve the formation of prothrombin activator by a cascade of activated procoagulants, the enzymatic use of prothrombin activator to liberate the active enzyme thrombin from prothrombin, and the use of thrombin to induce fibrinogen to form prothrombin chains fibrin. (pp. 649-652) c. The intrinsic pathway depends on the (intrinsic) substances present in the blood. It has many more steps and intermediate stages and is slower. The extrinsic mechanism bypasses the initial steps of the intrinsic mechanism and is triggered by tissue factor (thromboplastin) released from damaged cells in the vessel wall or surrounding tissues. (pp. 650 and 651) d. Calcium is essential for virtually all stages of clotting. (p. 651) 20. a. Fibrinolysis is the removal of clots once healing has occurred. B. The importance of this process is that without it, the blood vessels would gradually become clogged with clots that are no longer needed. (p. 652) 21. a. Excessive growth of clots is usually prevented by rapidly removing clotting factors and inhibiting activated clotting factors. (pp. 652 and 653) b. Two conditions that can lead to unnecessary (and undesirable) clot formation are roughness of the vessel wall endothelium and blood pooling. (p. 653) 22. Bleeding disorders occur when the liver is unable to synthesize its usual supply of procoagulants. (p. 653) 23. a. A transfusion reaction involves the agglutination of foreign red blood cells, leading to blockage of small blood vessels and lysis of the donated red blood cells. It occurs when incompatible blood is transfused. B. Possible consequences are impaired oxygen carrying capacity, fever, chills, nausea, vomiting, general toxicity and renal failure. (p. 656) 24. Iron deficiency anemia due to insufficient intake of iron-rich foods or pernicious anemia due to vitamin B12 deficiency can be caused, among other things, by improper nutrition. (p. 642) 25. Among the most common blood problems in the elderly are chronic types of leukaemia, anemia and thromboembolic diseases. (p. 657)

Critical Thinking Problems and Clinical Applications 1. Hematopoiesis is a process involving fairly rapid cell production. Because chemotherapy drugs simply target cells that exhibit rapid turnover (rather than other properties specific to cancer cells), hematopoiesis is a target of chemotherapy drugs and must be carefully monitored. (pp. 638 and 639)

Copyright © 2010 Pearson Education, Inc.

Chapter 17

Sangre

2 The woman would likely receive a whole blood transfusion. It is important that it maintains sufficient O2-carrying capacity to meet fetal needs and blood volume to maintain circulation. B. Blood tests that would be performed include ABO and Rh antigen tests and crossmatching. (p. 654 and 655) 3. a. Polycythemia is responsible for his increased red blood cell count, since more red blood cells need to be produced to increase their O2-binding and transport capacity at the high altitude (thinner air) of the Alps. The increased production of red blood cells was driven by increased production of erythropoietin. B. Your red blood cell count will not be higher than normal because excessive red blood cell production decreases the production of erythropoietin in the kidneys when adequate amounts of O2 are carried in the blood. (p. 643) 4. Janie's white blood cells are immature or abnormal and cannot defend her body in the usual way. (p. 648) 5. The red bone marrow is the site of hematopoiesis and when it is destroyed by benzene, stem cells are not produced, reducing the production of megakaryocytes (the precursor cells to platelets involved in blood clotting). (p. 638) 6. Tyler produces a high rate of reticulocytes (immature red blood cells), which explains his high hematocrit. (p. 639) 7. An analysis of the coagulation process described in the text should reveal that the two proteins in the blood are thrombin and fibrinogen. (p. 650) 8. Elevated red blood cell counts may be associated with smoking, due to frequent hypoxia resulting from inhalation of deoxygenated cigarette smoke. (p. 643) 9. Aspirin is a mild anticoagulant that can cause excessive bleeding during or after surgery. (p. 653)

Suggested Reading Becker, R. "Antiplatelet Therapy." Scientific American: Science and Medicine 3 (July/August 1996): 12-21. Eaton, W. and J. Hofrichter. "The Biophysics of Sickle Cell Hydroxyurea Therapy". Science 268 (May 1995): 1142–1143. GRAZER, Walter. "Wright's Stuff". Nature 416 (6878) (March 2002): 275-277. Hardison, R. "The Evolution of Hemoglobin." American Scientist 87 (March/April 1999): 126-137. Lin, L. "Photochemical Treatment of Platelets with Psoralen." Science and Medicine 5 (January/February 1998): 54-63. Luzzatto, Lucio and Rosario Notaro. "Hemoglobin Companion". Nature 417 (6890) (2002 June): 703-705. Nucci, ML and A. Abuchowski. "The Search for Blood Substitutes". Scientific American 278 (February 1998): 72-77. Pickrell, J. "The Globin family is growing." Science News 161(15) (2002 Apr): 230. Radetsky, P. "The mother of all blood cells." Discover 16 (March 1995): 86–93. Roos, Dirk, and Christine C. Winterbourn. "Lethal Weapons". Science 296 (5568) (April 2002): 669-670. Shivdasani, R., et al. "The transcription factor NF-E2 is required for platelet formation independent of the effects of thrombopoietin/MGDF on megakaryocyte development." Cell 81 (June 1995): 695-705. Ziegler, BL, et al. "KDR receptor: a key marker defining hematopoietic stem cells". Science 285 (September 1999): 1553. Copyright © 2010 Pearson Education, Inc.

211

18

The cardiovascular system: the heart

Goals

physiology of the heart

heart anatomy

10. Name the components of the cardiac conduction system and trace the conduction path. 11. Draw a diagram of a normal electrocardiogram. Name each wave and interval and what they represent. 12. List some of the abnormalities that can be detected in an EKG recording. 13. Describe normal heart sounds and explain how heart murmurs differ. 14. Describe the timing and events of the cardiac cycle. 15. List and explain the effects of various factors that regulate stroke volume and heart rate. 16. Explain the role of the autonomic nervous system in regulating cardiac output.

1. Describe the size, shape, location, and orientation of the heart in the chest. 2. Name the shells of the heart. 3. Describe the structure and function of each of the three layers of the heart wall. 4. Describe the structure and functions of the four chambers of the heart. Name each camera and provide the name and general course of the associated large ship(s). 5. Trace the path of the blood through the heart. 6. Name the main branches and describe the distribution of the coronary arteries. 7. Name the heart valves and describe their location, function and mechanism of action.

aspects of cardiac development

Cardiac muscle fibers 8. Describe the structural and functional properties of cardiac muscle and how it differs from skeletal muscle. 9. Briefly describe the events of contraction of heart muscle cells.

17. Describe the formation of the fetal heart and how the fetal heart differs from the adult heart. 18. Give examples of age-related changes in heart function.

Suggested Lesson Plan I. Anatomy of the Heart (pp. 662-672; Figs. 18.1-18.10) A. Size, Location and Orientation (p. 663; Fig. 18.1) 1. The heart is the size of a fist and weighs 250-300 Gram. 2. The heart is located in the mediastinum and two-thirds to the left of the midline. 3. The base points to the right shoulder and the crown points to the left hip.

212 Copyright © 2010 Pearson Education, Inc.

Chapter 18

The cardiovascular system: the heart

B. Coverings of the Heart (p. 663; Fig. 18.2) 1. The heart is contained in a double-walled sac, the pericardium. 2. Deep below the pericardium is the serous pericardium. 3. The parietal pericardium lines the interior of the pericardium. 4. The visceral pericardium or epicardium covers the surface of the heart. C. Layers of the Heart Wall (pp. 663-664; Fig. 18.3) 1. The myocardium is composed primarily of cardiac muscle and forms the bulk of the heart. 2. The endocardium lines the ventricles of the heart. D. Ventricles and Associated Great Vessels (pp. 664-668; Fig. 18.4) 1. The right and left atria are the receiving chambers of the heart. 2. The right ventricle pumps blood to the pulmonary trunk; the left ventricle pumps blood into the aorta. E. Pathway of Blood through the Heart (pp. 668-669; Fig. 18.5) 1. The right side of the heart pumps blood into the pulmonary circulation; The left side of the heart pumps blood into the systemic circulation. F. Coronary Circulation (pp. 669-670; Fig. 18.7) 1. The heart is not supplied with blood as it passes through the ventricle. 2. The coronary circulation supplies blood to the cells of the heart. 3. In myocardial infarction, there is a prolonged coronary blockage that leads to cell death. G. Heart Valves (pp. 670-672; Figs. 18.8-18.10) 1. The mitral and tricuspid valves prevent backflow into the atria when the ventricles contract. 2. When the heart is relaxed, the AV valves are open and when the heart is contracting, the AV valves close. 3. The aortic and pulmonary valves are located in the main arteries exiting the heart. They prevent blood from flowing back into the heart chambers. 4. When the heart is relaxed, the aortic and pulmonary valves are closed, and when the heart is contracting, they are open.

II. Cardiac muscle fibers (pp. 672-676; Figs. 18.11-18.12) A. Microscopic anatomy (pp. 672-673; Fig. 18.11) 1. Cardiac muscle is striated and contracts via the sliding thread mechanism. 2. The cells are short, thick, branched and connected by intercalated discs. B. Mechanism and events of contraction (pp. 673-675; Fig. 18.12) 1. Some heart muscle cells are self-excitable. 2. The heart contracts as a unit or does not contract at all. 3. The heart's absolute refractory period is greater than that of skeletal muscle, thereby avoiding tetanic contractions. C. Energy Requirements (p. 675) 1. The heart relies solely on aerobic respiration for its energy requirements. 2. The heart muscle is able to switch nutrient pathways to utilize any available nutrient supply.

Copyright © 2010 Pearson Education, Inc.

213

214

Text and media guide to human anatomy and physiology

3. Cardiac physiology (pp. 676-687; Figs. 18.13-18.23) A. Electrical events (pp. 676-680; Figs. 18.13-18.18) 1. The intrinsic conduction system consists of specialized heart cells that initiate and distribute impulses , which ensure that the heart depolarizes in an orderly manner. 2. Autorhythmic cells have an unstable resting potential, called the pacemaker potential, that is constantly depolarizing. 3. Impulses pass through the autorhythmic heart cells in the following order: SA node, AV node, AV bundle, right and left bundle branch and Purkinje fibers. 4. The autonomic nervous system alters the heartbeat: the sympathetic center increases the rate and depth of the heartbeat, and the parasympathetic center slows it down. 5. An electrocardiograph monitors and amplifies the heart's electrical signals and records them as an electrocardiogram (ECG). B. Heart sounds (p. 681; Fig. 18.19) 1. Normal a. The first sound, lub, corresponds to AV valve closure and is produced during ventricular systole. B. The second tone, dup, corresponds to the closing of the aortic and pulmonary valves and is produced during ventricular diastole. 2. Abnormal a. Heart murmurs are unusual heart sounds due to the turbulent backflow of blood through a valve that does not close tightly. C. Mechanical Events: The Cardiac Cycle (p. 682; Fig. 18.20) 1. Systole is the contractile phase of the cardiac cycle and diastole is the relaxation phase of the cardiac cycle. 2. A cardiac cycle is a series of pressure and volume changes in the heart during one beat. a. Ventricular filling occurs during mid or late ventricular diastole, when the AV valves are open, the semilunar valves are closed, and blood flows passively into the ventricles. B. The atria contract during ventricular late diastole, forcing the final volume of blood into the ventricles. C. The atria relax and the ventricles contract during ventricular systole, causing the AV valves to close and the semilunar valves to open as blood is expelled from the ventricles into the great arteries. i.e. During early diastole, isovolumic relaxation occurs, resulting in a rapid drop in ventricular pressure, causing the semilunar valves to close and the AV valves to open. D. Cardiac Output (pp. 682-687; Figs. 18.21-18.23) 1. Cardiac output is defined as the amount of blood pumped out of a heart chamber per beat and is calculated as the product of stroke volume and heart rate. 2. Stroke Volume Adjustment a. Preload: The heart's Frank-Starling law states that the critical factor controlling stroke volume is the degree to which heart muscle cells stretch just before contraction.

Copyright © 2010 Pearson Education, Inc.

Chapter 18

The cardiovascular system: the heart

B. Contractility: The force of contraction increases as the cytoplasmic concentration of calcium ions increases. C. Afterload: ventricular pressure that must be exceeded before blood can be ejected from the heart. 3. Heart rate regulation a. Sympathetic stimulation of pacemaker cells increases heart rate and contractility, while parasympathetic inhibition of pacemaker cells decreases heart rate. B. epinephrine, thyroxine and calcium affect the heart rate. C. Age, gender, exercise and body temperature affect heart rate. 4. Homeostatic Imbalance of Cardiac Output a. Congestive heart failure occurs when the heart's pumping capacity is so slow that blood flow cannot meet the needs of the tissues. B. Pulmonary congestion occurs when one side of the heart fails, resulting in pulmonary edema.

4. Aspects of cardiac development (pp. 688-690; Figs. 18.24-18.25) A. Embryological development (pp. 688-689; Figs. 18.24-18.25) 1. The heart begins as a pair of endothelial tubes that connect and fuse to form to form a single heart tube with four bulges representing the four chambers. 2. The foramen ovale is an opening in the interatrial septum that allows blood returning to the pulmonary circulation to be directed to the atrium of the systemic circulation. 3. The ductus arteriosus is a vessel that runs between the pulmonary trunk and the aortic arch and allows blood to drain from the pulmonary trunk into the aorta. B. Aspects of the Aging Heart (pp. 689-690) 1. Sclerosis and thickening of the valve leaflets occur over time in response to the constant pressure of blood against the valve leaflets. 2. The decrease in cardiac reserve is due to a decrease in the efficiency of sympathetic stimulation. 3. Myocardial fibrosis can occur in the nodes of the intrinsic conduction system and lead to arrhythmias. 4. Atherosclerosis is the gradual deposition of fatty plaques on the walls of systemic vessels.

Cross-references For more information on the topics covered in Chapter 18, see the chapters listed below. 1st 2nd 3rd 4th 5th 6th 7th

Chapter chapter chapter chapter chapter chapter chapter

1: ventral body cavity; mediastinum 3: cell junctions 4: serous membranes; cardiac muscle; squamous epithelium; Collagen 9: mechanisms of filament sliding 11: membrane potential 12: control of heart rate by the spinal cord 13: vagus nerve

Copyright © 2010 Pearson Education, Inc.

215

216

Text and Media Teacher's Guide to Human Anatomy and Physiology 8. Chapter 14: Neurotransmitters and Heart Rate; general sympathetic and parasympathetic function 9. Chapter 19: Arteriosclerosis; hydrostatic pressure and fluid movement; regulation of cardiac output and blood pressure; vasomotor centers and blood pressure control; role of baroreceptors and chemoreceptors in blood pressure control; control of volume and blood pressure; Blood flow to the heart 10. Chapter 22: Function of the pulmonary arteries and veins 11. Chapter 28: Fetal circulation and changes during labour

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 30: Cardiac anatomy Exercise 31: Cardiac conduction system and PhysioEx™ 8.0 electrocardiography Exercise 34B: Frog cardiovascular physiology: computer simulation 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 30: Cardiac Anatomy Exercise 31: PhysioEx™ 8.0 Electrocardiography and Cardiac Conduction System Exercise 34B: Frog Cardiovascular Physiology: Computer Simulation

Teaching Tips 1. Point out that the visceral layer of the pericardium (epicardium) is the same as the outermost layer of the heart wall. 2. Show a single diagram of the pericardium and heart wall to give students an overview of the structure. 3. Distinguish clearly between the atrium and the pinna. 4. Point out that blood flow through the right and left sides of the heart is simultaneous and that the direction of flow progresses from the atrium to the ventricle on both sides, with both sides of the heart pumping the same volume of blood. 5. Describe the design differences between atrioventricular valves and crescent valves and why the design of each valve type works best in its location. Point out that valves are not rigid structures, they are fragile structures. 6. Compare ion movement, depolarization and repolarization in cardiac muscle with that in skeletal muscle. Emphasize why a prolonged repolarization phase is important for heart muscle function. 7. Emphasize that pacemaker cells are cardiac muscle cells that have been simply modified to spontaneously depolarize. 8. Distinguish clearly between the fundamental rate, established by the heart's conduction system, and the acceleration or inhibition controls (sympathetic and parasympathetic), established by the medulla. 9. Emphasize that the ECG is a measure of the total electrical activity of the heart at the body's surface. Students often wonder why the EKG doesn't look like an action potential. 10. When discussing ventricular systole and diastole, reinforce the root word definitions to allow students to think critically about the meaning instead of memorizing the terminology, e.g. B. Isovolumetric means “equal volume”.

Copyright © 2010 Pearson Education, Inc.

Chapter 18

The cardiovascular system: the heart

11. Emphasize the relationship between pressure changes in the ventricles and blood flow through the heart. The concepts of pressure gradients and flow are often new to students. 12. Note that while the ventricles have a passive and active phase for filling, the atria only fill passively. 13. Relate the heart sounds to specific points in the heart cycle discussion to help students incorporate these ideas. 14. Distinguish clearly between preload as a function of mechanical strain and contractility as a function of the stimulus force of the contraction. 15. Discuss the importance of most of the blood volume bypassing the fetal lungs and the role of the foramen ovale and ductus arteriosus. Emphasize the importance of closing these structures after birth.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Play a recording of normal and abnormal heart sounds to accompany your presentation of valve function and dysfunction. ("Heart Sound Interpretation" is available to borrow free of charge from the chapters of the American Heart Association.) 3. Obtain normal and abnormal EKG recordings. Determine what is defective in the cardiac conduction system to produce the abnormal recordings. 4. Record the student volunteers' heartbeats as they stand and walk for a few minutes. Using a standard stroke volume, calculate the change in cardiac output. 5. Use heart models and prepared specimens to show the anatomy of the heart and its position in the thoracic cavity. 6. Using dissected animal specimens, compare fetal cardiac structures to adult structures.

Critical Thinking/Topics for Discussion 1. Relate the working of the heart to the working of a water pump. Include problems associated with low blood pressure to the heart and high blood pressure to the heart. 2. Discuss the signs of an impending heart attack. 3. Compare the meaning of ventricular fibrillation with atrial fibrillation. 4. Discuss the role of the heart muscle in ejecting blood from the ventricles instead of blood from the atria. 5. How would cardiac function change if AV node cells were depolarized faster than SA node cells? 6. What would happen to the heart (and the rest of the body) over time if partial blockage of the semilunar aortic valve occurs? 7. Discuss the symptoms and possible problems in a person with mitral valve prolapse. 8. Investigate the effect of digoxin as a therapy for heart murmurs. 9. Identify long-term stress and its role in hypertensive heart disease.

Library Research Topics 1. Investigate the role of antihypertensive drugs in cardiac activity. 2. Study alternatives to coronary bypass surgery. Copyright © 2010 Pearson Education, Inc.

217

218

Text and media manual for teachers of human anatomy and physiology 3rd 4th 5th 6th 7th 8th

Examine the known effects of street drugs on cardiac activity. Study the effect of smoking on the heart and its function. Examine the criteria for heart transplants and their success rate. Study the effect of exercise on heart function. Identify pacemaker use and what specific problems they are designed to address. Assess the status of artificial hearts or external heart pumps. Identify progress and problems. 9. Examine fetal heart defects and outline progress in treatment. 10. Research diagnostic tests used to measure heart health and what they should show.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all chapter-specific online media resources for Chapter 18 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 18.1 Anatomy of the Heart (pp. 662-672) Physiology® Interactive Systems Set of 10: Overview of the Anatomy of the Cardiovascular System: The Heart Artist's Caption: General Anatomy of the Heart, Anterior View (Fig. 18.4b, p. 665 ) Artist Caption: Gross Anatomy of the Heart, Internal View (Fig. 18.4e, p. 667) Memory Game: The Structure of the Heart Section 18.2 Cardiac Muscle Fibers (pp. 672-676) Physiology® Interactive Systems Set of 10: Cardiac Action Potential Section 18.3 Physiology of the Heart ( pp. 676-687) MP3 Session Tutor: Cardiovascular Pressure Physiology® Interactive Systems Set of 10: Intrinsic Conduction System Interactive Systems Physiology® Set of 10: Cycle Interactive Systems Set Cardiac Physiology®: Cardiac Output PhysioEx™ 8.0: Cardiovascular Physiology Frog Case Study: Coronary Stenosis Case Study: Cardiac Arrhythmias Memory Game: The System Cardiovascular Theme Section 18.4 Developmental Aspects of the Heart (pp. 688-690) Chapter Summary Kre uzword 18.1 Crossword 18.2 Web Links Chapter he Quizzes Art Labeling Quiz Correspondence Quiz

Copyright © 2010 Pearson Education, Inc.

Chapter 18

The cardiovascular system: the heart

Multiple Choice Quiz True-or-False Quiz Chapter Practice Test Study Tools Histology Atlas myeBook Flashcards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1. The circulatory system: two hearts beating as one (FHS; 28 min, 1989). This program from The Living Body series describes the structure and function of the heart. 2. Diagnosis of heart disease (FHS; 18 min, 1994). He talks about heart disease, the warning signs of a heart attack, EKGs and cardiac catheterization. Helps students visualize the different tests used to diagnose heart problems. 3. Heart attack (FHS; 50 min, 2000). From the series The Body Invaders, this show looks at the causes, symptoms and treatment of atherosclerosis. 4. Heart Valves: Heart Repair (FHS; 19 min). Describes the symptoms and treatment of aortic stenosis. It covers the features of angioplasty, the use of a pacemaker, and an implantable defibrillator. 5. The Human Cardiovascular System: The Heart Videotape (BC; 25 min., 1995). A sheep heart is used to illustrate the heart's structure and function, along with dissected human specimens and the cadaver to show the coronary artery and great vessels of the heart. 6. Pumping Life: Heart and Circulation (WNS; 20 min.). Explain the structure and function of the heart. It uses animation and live action. Discuss heart problems and the importance of preventative maintenance.

A.D.A.M.® Interactive Anatomy® 4.0 software (see full list on page 9 of this manual). A.D.A.M.® MediaPro (see page 9 of this manual for a complete list). A.D.A.M.® Anatomy Practice (see page 87 of this manual for a complete list). LOGAL® Biology Explorer™ CD-ROM: The cardiovascular system (WNS; Win/Mac). This program illustrates the role that the heart plays in the functioning of the human body. He studies the heart and its function, the effects of medication, the conditioning of the heart, and various heart diseases. 5. Interactive Physiology® 10-System Suite: Cardiovascular System (BC; Win/Mac 2008). Presents topics related to the physiology of the heart and blood vessels, such as blood pressure, cardiac output, the intrinsic conduction system, the cardiac action potential, and the cardiac cycle. 1st 2nd 3rd 4th

Copyright © 2010 Pearson Education, Inc.

219

220

Human Anatomy and Physiology Instructor's Text and Media Guide 6. Practice Anatomy Lab™ 2.0: Human cadaver, anatomical models, histology, cat, fetal pig (see page 9 of this guide for a complete list). 7. The Ultimate Human Body, version 2.2 (see page 9 of this manual for the full list).

Material to improve the lesson Thumbnails of all illustrations in Chapter 18 are in Appendix B.

Instructor Transparency Index/Resource DVD Figure 18.1 Figure 18.2 Figure 18.3 Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure

18,4 18,5 18,6 18,7 18,8 18,9 18,10 18,11 18,12 18,13 18,14

Figure 18.15 Figure 18.16 Figure 18.17 Figure 18.18 Figure 18.19 Figure 18.20 Figure 18.21 Figure 18.22 Figure 18.23 Figure 18.24

Position of the heart in the mediastinum. The layers of the pericardium and the layers of the heart wall. The circular and spiral arrangement of cardiac muscle bundles in the myocardium of the heart. Gross anatomy of the heart. The systemic and pulmonary circuits. Anatomical differences between the right and left ventricle. Cardiovascular. Heart valves. The atrioventricular valves. crescent flaps. Microscopic anatomy of the heart muscle. The action potential of contractile heart muscle cells. Pacemakers and action potentials of autorhythmic heart cells. Cardiac conduction system and sequence of action potentials during a heartbeat. Autonomic innervation of the heart. Recording an electrocardiogram (lead I). The sequence of depolarization and repolarization of the heart related to the deflection waves of an ECG trace. Normal and abnormal ECG recordings. Areas of the chest surface where heart sounds are best detected. Summary of events during the cardiac cycle. Norepinephrine increases cardiac contractility through a cyclic AMP second messenger system. Factors involved in the regulation of cardiac output. development of the human heart. Three examples of congenital heart defects.

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 10. The heart is located in the mediastinum. It is located in front of the spine and behind the breastbone. It leans slightly to the left. (p. 663) 11. The pericardium has two layers, one fibrous and one serous. The outer fibrous layer is a fibrous connective tissue that protects the heart and anchors it to surrounding structures. The inner serous layer (squamous epithelial cells) lines the

Copyright © 2010 Pearson Education, Inc.

Chapter 18

12

13

14

fifteen.

sixteen.

17

18

19

20

The cardiovascular system: the heart

Fibrous layer as the serous and parietal pericardium at the base of the heart continues across the heart surface as the visceral serous pericardium. The visceral serous pericardium is the outermost layer of the heart wall, i.e. the epicardium. (p. 663) Blood entering the right atrium on its way to the left atrium is in the pulmonary circulation. The course is as follows: right atrium, right ventricle, pulmonary trunk, right and left pulmonary arteries, lungs, pulmonary veins, left atrium. This circuit is called the pulmonary circuit. (p. 663) The coronary arteries actively supply blood to the myocardium when the heart is relaxed. The coronary vessels become compressed and fail to deliver blood when the ventricles contract. (p. 670) b. The main branches of the coronary arteries and the areas they serve are as follows: The left coronary artery runs to the left side of the heart and divides into the anterior interventricular artery and the circumflex artery. The anterior interventricular artery supplies blood to the interventricular septum and the anterior walls of both ventricles, and the circumflex artery supplies the left atrium and the posterior walls of the left ventricle. The right coronary artery divides on the right side of the heart, where it divides into the marginal artery and the posterior interventricular artery. The marginal artery supplies the right lateral myocardium of the heart and the posterior interventricular artery, which runs to the apex of the heart and supplies the posterior ventricular walls. (pp. 669-670) A longer myocardial refractory period is desirable because it prevents the heart from going into prolonged or tetanic contractions that would disrupt its pumping action. (p. 673) The elements of the heart's intrinsic conduction system, beginning with the pacemaker, are: SA node or pacemaker, AV node, AV bundle, right and left bundle branch, and Purkinje fibers. (p. 677) b. This system works to initiate and distribute impulses throughout the heart so that the myocardium depolarizes and contracts in an orderly and sequential fashion from the atria to the ventricles. (p. 676) See Figure 18.16. The P wave results from the propagation of impulses from the SA node through the atria. The QRS complex results from ventricular depolarization and precedes ventricular contraction. Its shape reflects the different sizes of the two ventricles and the time each takes to depolarize. The T wave is caused by ventricular repolarization. (pp. 679-680) The cardiac cycle includes all events associated with the flow of blood through the heart during a complete heartbeat. A cycle includes a period of ventricular filling (mid to late diastole, culminating in atrial systole), ventricular systole, and isovolumic relaxation (early diastole). (p. 682) Cardiac output is the amount of blood pumped from each ventricle in one minute. It can be calculated using the following equation: heart output heart rate stroke volume. (p. 682) The Frank-Starling law explains that the critical factor controlling stroke volume is the degree to which the heart muscle cells stretch just before contraction. The important factor in heart muscle stretching is the amount of blood that returns to the heart and stretches its ventricles. (p. 684) In a fetus, the combined function of the foramen ovale and ductus arteriosus is to allow blood to be diverted from the pulmonary circulation. B. If these shunts are left patent after birth, the gap will prevent adequate gas exchange, O2 loading, and CO2 unloading into the pulmonary circulation. (pp. 688 and 689)

Copyright © 2010 Pearson Education, Inc.

221

222

Text and media guide to human anatomy and physiology

Critical Thinking Issues and Clinical Application 1. Cardiac tamponade is compression of the heart due to accumulation of blood or inflammatory fluid in the pericardium. This compression reduces the heart's ability to beat and function as an effective pump, leading to an inadequate blood supply (leading to ischemia and cyanosis) and eventually cardiogenic shock. (p. 663) 2. a. To auscultate the aortic valve, place the stethoscope over the second intercostal space at the right sternal border. To auscultate the mitral valve, place the stethoscope over the apex of the heart in the fifth intercostal space, in line with the midline of the clavicle. (p. 670) b. These abnormal murmurs would be heard most clearly during ventricular diastole of the aortic valve and during atrial systole of the mitral valve. (pp. 670-671) c. An incompetent valve hisses after the valve supposedly closes. A stenotic valve makes a high-pitched sound when blood is forced through its narrowed opening during systole, just before the valve closes. (p. 672) 3. Failure of the left ventricle (which pumps blood around the body) can result in chest pain due to dead ischemic or dead heart cells; pale and cold skin due to lack of blood flow due to blocked ventricular contraction; and wet murmurs in the lower part of the lungs due to the high pressure and pooling of blood in the pulmonary circulation due to the non-functioning left ventricle. (pp. 670, 675) 4. Deoxygenated blood returning to the right heart from the systemic circulation is repeatedly recirculated through the systemic circulation, while oxygenated blood returning from the lungs is continuously recirculated through the pulmonary circulation. (pp. 688-689) 5. Gabriel, who was a drug user, probably became infected with a bacteria-contaminated ("dirty") needle used to administer heroin. (p. 681) 6. Synonyms are as follows: (a) coronary sulcus, (b) right AV valve, (c) left AV or mitral valve, and (d) atrioventricular bundle or bundle of His. (pp. 664, 670, 677)

Recommended reading Anversa, P. and B. Nadal-Ginard. "Myocyte renewal and ventricular remodeling". Nature 415 (6868) (January 2002): 240-243. Bers, DM "Cardiac Excitation-Contraction". Nature 415 (6868) (January 2002): 198–205. BONETA, Laura. "New study on the aging heart". Nature Medicine 8(3) (March 2002): 201. Dajer, Tony. "Scanning the Depths". Discover 23(3) (March 2002): 22–25. Gottleib, Roberta A., and Richard N. Kitsis. "See death in the living." Nature Medicine 7 (12) (December 2001): 1277-1278. Harder, B. "Vitamin Void." Science News 161(7) (February 2002): 161. Hoffman-Kim, Diane. "Tissue Engineering: Heart Valves". Science and Medicine 8 (March/April 2002): 62–64. Isner, J.M. "Myocardial Gene Therapy." Nature 415 (6868) (January 2002): 234-239. Marban, E. "Cardiac Canalopathies." Nature 415 (6868) (January 2002): 213-218. Nattel, S. "New Thoughts on Atrial Fibrillation 50 Years Later." Nature 415 (6868) (January 2002): 219–226. Rockman, H.A., W.J. Koch, and R.J. Lefkowitz. "Seven transmembrane receptors and cardiac function". Nature 415 (6868) (January 2002): 206-212. Towbin, JA and N.E. Bowles. "The Weak Heart". Nature 415 (6868) (January 2002): 227-233. Vane, John R. "Are you taking an aspirin every day again?" Science 296 (5567) (April 2002): 474-475.

Copyright © 2010 Pearson Education, Inc.

The cardiovascular system: blood vessels

19

8. Define hypertension. Describe their manifestations and consequences.

Objectives PART 1: GENERAL DESCRIPTION OF BLOOD VESSEL STRUCTURE AND FUNCTION Structure of blood vessel walls 1. Describe the three layers that normally make up the wall of a blood vessel and give the function of each. 2. Define vasoconstriction and vasodilation. Arterial System 3. Compare and contrast the structure and function of the three types of arteries.

Blood flow through body tissues: tissue perfusion 9. Explain how blood flow is regulated in the body in general and in its specific organs. 10. Describe the factors involved in capillary dynamics and explain their importance. 11. Define circulatory shock. Name several possible causes. PART 3: CIRCULATORY PATHWAYS: BLOOD VESSELS OF THE BODY The two main circulatory systems of the body

Capillaries 4. Describe the structure and function of a capillary bed. Venous system 5. Describe the structure and function of veins and explain how veins differ from arteries. PART 2: PHYSIOLOGY OF CIRCULATION Introduction to blood flow, blood pressure and resistance 6. Define blood flow, blood pressure and resistance and explain the relationships between these factors. Systemic blood pressure 7. List and explain the factors that affect blood pressure and describe how blood pressure is regulated.

12. Trace the course of blood through the pulmonary circuit and indicate the importance of this particular circuit. 13. Describe the general functions of the systemic circulation. Main vessels of the systemic circulation 14. Name the main arteries and veins of the systemic circulation and indicate their location. 15. Describe the structure and the special function of the hepatic portal system. Aspects of blood vessel development 16. Explain how blood vessels develop in the fetus. 17. Give examples of changes that commonly occur in blood vessels with age.

223 Copyright © 2010 Pearson Education, Inc.

224

Text and media guide to human anatomy and physiology

TEACHING SUGGESTIONS PART 1: OVERVIEW OF STRUCTURE AND FUNCTION OF BLOOD VESSELS (pp. 694-703; figs. 19.1-19.5; table 19.1) I. Structure of blood vessel walls (p. 695; figs. 19.1-19.2, table 19.1) A. The walls of all but the smallest blood vessels consist of three layers: tunica intima, tunica media, and tunica externa (p. 695; Fig. 19.1). B. The tunica intima reduces friction between the vessel walls and the blood; the tunica media controls vasoconstriction and vasodilation of the vessel; and the outer hull protects, strengthens, and anchors the ship to surrounding structures (p. 695; Fig. 19.2; Table 19.1).

II. Arterial System (pp. 695-698; Fig. 19.2; Tables 19.1-19.2) A. The elastic or conductive arteries contain large amounts of elastin, which allows them to withstand and cushion pressure fluctuations due to cardiac activity (p. 697, Fig. 19.2, Table 19.1). B. Muscular or distributional arteries carry blood to certain organs of the body and have the highest proportion of tunica media of any vessel, making them more active in vasoconstriction (p. 698; Table 19-1). C. Arterioles are the smallest arteries and regulate blood flow to capillary beds through vasoconstriction and vasodilation (p. 698).

3. Capillaries (pp. 698-700; Fig. 19.3-19.4; Tab. 19.1) A. Capillaries are the smallest vessels and enable the exchange of substances between blood and interstitial fluid (pp. 698-699; Fig. 19.3 Tab. 19.1) . 1. Continuous capillaries are the most common and allow passage of liquids and small solutes. 2. Windowed capillaries are more permeable to liquids and dissolved substances than continuous capillaries. 3. Sinus capillaries are leaky capillaries that allow the passage of large molecules between the blood and surrounding tissues. B. Capillary beds are microcirculatory networks composed of a vascular shunt and true capillaries that act as exchange vessels (pp. 699-700; Fig. 19.4). C. A cuff of smooth muscle called the precapillary sphincter surrounds each capillary of the metateriole and acts as a valve to regulate blood flow into the capillary (p. 700; Fig. 19-4).

4. Venous system (pp. 700-701; Fig. 19.5; Tab. 19.1) A. Venules form where capillaries converge, allowing fluid and white blood cells to move easily between blood and tissues (p. 700; Tab 19.1). B. The venules unite to form veins, which are relatively thin-walled vessels with large lumens containing about 65% of the total blood volume (pp. 700-701; Fig. 19.5; Table 19.1).

V. Vascular Anastomoses (pp. 701, 703) A. Vascular anastomoses form where vascular channels meet, allowing blood to flow to and from an area even when a channel is blocked (p. 701).

Copyright © 2010 Pearson Education, Inc.

Chapter 19

The cardiovascular system: blood vessels

PART 2: PHYSIOLOGY OF CIRCULATION (pp. 703 to 721; Figs. 19.6 to 19.18; Table 19.2) VI. Introduction to Blood Flow, Blood Pressure and Resistance (pp. 703-704) A. Blood flow is the volume of blood flowing through a vessel, organ or the entire circulatory system in a given period of time and can be expressed in ml/. minute (p. 703). B. Blood pressure is the force per unit area that blood exerts against a vessel wall and is expressed in millimeters of mercury (mm Hg) (p. 703). C. Drag is a measure of the friction between the blood and the vessel wall and is derived from three sources: blood viscosity, blood vessel length, and blood vessel diameter (p. 704). D. Relationship between flow, pressure, and resistance (p. 704) 1. When blood pressure increases, blood flow increases; As peripheral resistance increases, blood flow decreases. 2. Peripheral resistance is the most important factor affecting local blood flow since vasoconstriction or vasodilation can drastically alter local blood flow while systemic blood pressure remains unchanged.

VIII. Systemic blood pressure (pp. 704 and 706; Figs. 19.6 and 19.7) A. The pumping action of the heart produces blood flow; Pressure occurs when there is resistance to blood flow (p. 704). B. Systemic blood pressure is highest in the aorta and decreases along the way until it reaches 0 mm Hg in the right atrium (p. 705; Fig. 19.6). C. Arterial blood pressure reflects the number of arteries near the heart that can be dilated (compliant or compliant) and the volume imposed on them at any given time (p. 705; Fig. 19.6). 1. When the left ventricle contracts, blood is pushed into the aorta, creating a pressure spike called the systolic pressure (120 mm Hg). 2. Diastolic pressure occurs when the closed crescent valve prevents backflow of blood into the ventricles and the aorta recedes (70 to 80 mmHg). 3. The difference between diastolic and systolic pressure is called pulse pressure. 4. Mean arterial pressure (MAP) represents the pressure that drives blood to the tissues. D. The pressure of the arterial capillaries is low, between 40 and 20 mm Hg, which protects the capillaries from rupture but is still sufficient to ensure exchange between blood and tissues (p. 705; Fig. 19.6). E. Arterial venous pressure changes very little during the cardiac cycle and is low, reflecting the cumulative effect of peripheral resistance (pp. 705-706; Fig. 19.7).

VIII. Maintenance of blood pressure (pp. 706-713; Figs. 19.8-19.12; Table 19.2) A. Blood pressure varies directly with changes in blood volume and cardiac output, which are mainly determined by venous return and cardiac output. Neural and hormonal control (p. 706, figure 19.8). B. Short-term neural controls of peripheral resistance alter blood distribution to meet specific tissue requirements and maintain adequate MAP by altering blood vessel diameter (pp. 706–709; Fig. 19–9). 1. The vasomotor center is a group of sympathetic neurons in the spinal cord that controls changes in the diameter of blood vessels.

Copyright © 2010 Pearson Education, Inc.

225

226

Text and Media Teacher's Manual of Human Anatomy and Physiology 2. Baroreceptors sense stretch and send impulses to the vasomotor center, inhibiting its activity and promoting vasodilation of arterioles and veins. 3. Chemoreceptors sense an increase in blood carbon dioxide levels and stimulate the cardiac accelerator and vasomotor centers, increasing cardiac output and vasoconstriction. 4. Cortex and hypothalamus can modify blood pressure by signals from medullary centers. C. Chemical controls affect blood pressure by acting on vascular smooth muscle or the vasomotor center (p. 709; Table 19-2). 1. Norepinephrine and epinephrine promote increased cardiac output and general vasoconstriction. 2. Atrial natriuretic peptide acts as a vasodilator and aldosterone antagonist, causing a reduction in blood volume. 3. Antidiuretic hormone promotes vasoconstriction and water conservation by the kidneys, resulting in increased blood volume. 4. Angiotensin II acts as a vasoconstrictor and additionally promotes the release of aldosterone and antidiuretic hormone. 5. Factors derived from the endothelium promote vasoconstriction and are released in response to low blood flow. 6. Nitric Oxide is produced in response to high blood flow or other signaling molecules and promotes systemic and localized vasodilation. 7. Inflammatory chemicals like histamine, prostacyclin, and kinins are powerful vasodilators. 8. Alcohol inhibits the release of antidiuretic hormone and vasomotor center, resulting in vasodilation. D. Long-Term Mechanisms (p. 710; Figs. 19.10-19.11) 1. The direct renal mechanism counteracts the increase in arterial pressure by altering blood volume and thereby increasing renal filtration rate. 2. The indirect renal mechanism is the renin-angiotensin mechanism, which counteracts the drop in blood pressure that causes systemic vasoconstriction. E. Monitoring of circulatory efficiency is achieved by measuring pulse and blood pressure; these values, together with respiratory rate and body temperature, are called vital signs (pp. 710-712; Fig. 19.12). 1. A pulse is generated by alternately stretching and retracting the elastic arteries during each cardiac cycle. 2. Systemic blood pressure is measured indirectly by the auscultatory method, which is based on the use of a blood pressure cuff to alternately stop and reopen blood flow in the brachial artery of the arm. F. Changes in blood pressure can result in transient or sustained hypotension (low blood pressure) or hypertension (high blood pressure) (pp. 712-713).

IX. Blood Flow Through Body Tissues: Tissue Perfusion (pp. 713-721; Figs. 19.13-19.18) A. Tissue perfusion is involved in the delivery of oxygen and nutrients to and removal from tissue cells; gas exchange in the lungs; absorption of nutrients from the digestive tract; and formation of urine in the kidneys (p. 713; Fig. 19.13). B. The rate or velocity of blood flow changes as it travels through the systemic circulation; it is fastest in the aorta and slows down with decreasing vessel diameter (pp. 713-714; Fig. 19.14).

Copyright © 2010 Pearson Education, Inc.

Chapter 19

The cardiovascular system: blood vessels

C. Autoregulation: Local Regulation of Blood Flow (pp. 714-715; Fig. 19.15) 1. Autoregulation is the automatic adjustment of blood flow to each tissue in relation to its needs and is intrinsically controlled by changing the diameter of local arterioles. 2. Self-regulating metabolic regulation is strongly stimulated by the lack of oxygen in the tissue. 3. Myogenic control involves the localized response of vascular smooth muscle to passive stretch. 4. Long-term autoregulation develops over weeks to months and involves an increase in the size of existing blood vessels and an increase in the number of vessels in a given area, a process termed angiogenesis. D. Blood Flow in Specific Areas (pp. 715-717) 1. Blood flow to skeletal muscle varies with activity level and fiber type. 2. Muscle autoregulation occurs almost exclusively in response to decreased oxygen levels. 3. Cerebral blood flow is tightly regulated to meet neural needs, since neurons cannot tolerate periods of ischemia, and increased blood carbon dioxide levels cause marked vasodilation. 4. In the skin, local autoregulatory processes control the supply of oxygen and nutrients to cells, while neural mechanisms control the body's temperature-regulating function. 5. The autoregulatory control of blood flow to the lungs is the opposite of what occurs in most tissues: low lung oxygen causes vasoconstriction, while high oxygen causes vasodilation. 6. The movement of blood through the coronary artery of the heart is affected by aortic pressure and the pumping of the ventricles. E. Blood flow through the capillaries and capillary dynamics (pp. 717-719; Figs. 19.16-19.17) 1. Vasomotion, the slow, intermittent flow of blood through the capillaries, reflects the action of the precapillary sphincters in response to local self-control. regulatory 2. The capillary exchange of nutrients, gases and metabolic waste occurs between the blood and the interstitial space by diffusion. 3. Hydrostatic Head (HP) is the force of a fluid against a diaphragm. 4. Colloidal osmotic pressure (COP), the force opposing hydrostatic pressure, is created by the presence of large, non-diffusible molecules that are prevented from moving across the capillary membrane. 5. Fluids flow out of the capillaries when net HP exceeds net OP, but fluids enter the capillaries when net OP exceeds net HP. F. Circulatory shock is any condition in which blood volume is insufficient and cannot circulate normally, resulting in blood flow that cannot meet the needs of a tissue (pp. 719-721; Fig. 19.18). 1. Hypovolemic shock results from massive blood loss and may be characterized by increased heart rate and severe vasoconstriction. 2. Vascular shock is characterized by normal blood volume but extreme vasodilation, often associated with loss of vasomotor tone, resulting in poor perfusion and a rapid drop in blood pressure. 3. Transient vascular shock occurs due to prolonged exposure to heat, such as B. Sunbathing, which causes vasodilation of skin blood vessels.

Copyright © 2010 Pearson Education, Inc.

227

228

Text and media Teacher's manual of human anatomy and physiology 4. Cardiogenic shock occurs when the heart is too inefficient to maintain normal blood flow and is usually associated with myocardial damage such as repeated heart attacks.

PART 3: CIRCULAR PATHS: BLOOD VESSELS OF THE BODY (pp. 721-745; Figs. 19.19-19.30; Tab. 19.3-19.13) X. The two main circuits of the body (p. 721; Figs. 19.19-19.20; Tab. 19.3) A There are two distinct pathways to and from the heart: The pulmonary circuit runs from the heart to the lungs and back to the heart; The systemic circulation goes through all parts of the body before returning to the heart.

XI. Systemic arteries and veins: differences in pathways and pathways (p. 721; Table 19.12) A. There are some important differences between arteries and veins (p. 721; Table 19.12). 1. There is one terminal systemic artery, the aorta, but two terminal systemic veins: the superior and inferior vena cava. 2. The arteries are deep and well protected, but the veins are deep, running parallel to the arteries, and superficial, running just under the skin. 3. Arterial pathways are usually clear, but in venous pathways there are often many connections making them difficult to follow. 4. There are at least two areas where venous drainage does not parallel arterial supply: the dural sinuses, which drain the brain, and the hepatic portal system, which drains from the digestive organs to the liver before entering the main circulation.

XII. Major vessels of the systemic circulation (pp. 721-745; Fig. 19.21-19.30; Tab. 19.4-19.13) A. Four pairs of arteries supplying the head and neck (pp. 726-727; Fig. 19.22; Tab. 19.5) . B. The upper extremities are supplied entirely by arteries arising from the subclavian arteries (pp. 728-729; Fig. 19.23; Table 19.6). C. The arterial supply of the abdomen originates from the aorta (pp. 730-733; Fig. 19.24; Table 19.7). D. The internal iliac artery primarily serves the pelvic region; the external ilium supplies blood to the lower extremity and abdominal wall (pp. 734-735; Fig. 19.25; Table 19.8). E. The vena cava is the main tributary of the venous circulation (pp. 736-737; Fig. 19.26; Table 19.9). F. The blood draining from the head and neck is collected by three pairs of veins (pp. 738-739; Fig. 19.27; Table 19.10). G. The deep veins of the upper extremities follow the course of the accompanying arteries (pp. 740-741; Fig. 19.28; Table 19.11). H. Blood draining from the abdominal and pelvic viscera and abdominal walls returns to the heart via the inferior vena cava (pp. 742-743; Fig. 19.29; Table 19.12). I. Most of the deep veins of the lower extremity have the same names as the arteries that accompany them (p. 744; Fig. 19.30; Table 19.13).

Copyright © 2010 Pearson Education, Inc.

Chapter 19

The cardiovascular system: blood vessels

XIII. Aspects of development of blood vessels (p. 745) A. The vascular endothelium consists of mesodermal cells that accumulate in islets of blood throughout the embryo, giving rise to dilatations that form rudimentary vascular tubes (p. 745). B. In the fourth week of development, the heart and vestigial vessels circulate with blood (p. 745). C. Fetal vascular changes include shunts to bypass the fetal lungs (foramen ovale and ductus arteriosus), the ductus venosus, which bypasses the liver, and the umbilical arteries and veins, which carry blood to and from the placenta (p. 745) . D. At birth, the fetal shunts and shunts are closed and occluded (p. 745). E. Congenital vascular problems are rare, but the incidence of vascular disease increases with age, causing varicose veins, tingling in the fingers and toes, and muscle spasms (p. 745). F. Arteriosclerosis begins in youth but rarely causes problems into old age (p. 745). G. Blood pressure changes with age: Blood pressure in infants is about 90/55 but rises steadily during infancy to an average of 120/80 and eventually rises to 150/90 with age (p. 745).

Cross-references For more information on the topics covered in Chapter 19, see the chapters listed below. 1. Chapter 3: Fixed Joints; Diffusion; Osmosis 2. Chapter 4: Simple squamous epithelium; dense connective tissue; elastic connective tissue 3. Chapter 9: Smooth muscles 4. Chapter 12: Blood-brain barrier; Mark; Hypothalamus 5. Chapter 13: Sensory Receptors 6. Chapter 14: Sympathetic Control; Epinephrine and Norepinephrine 7. Chapter 16: Atrial Natriuretic Peptide 8. Chapter 17: Properties of Blood 9. Chapter 18: Cardiac Output; cardioinhibitory and cardioaccelerating centers 10. Chapter 20: Relationship between blood capillaries and lymphatic capillaries; Factors affecting the movement of liquids through the capillary membranes; The factors that support venous return are the same as those that support lymphatic return 11. Chapter 23: Splanchnic Circulation 12. Chapter 24: Regulation of Blood Flow Does Not Control Body Temperature 13. Chapter 25: Antidiuretic Hormone and Aldosterone Function do not control the blood pressure; Effect of alcohol on antidiuretic hormone (and therefore blood pressure); Role of fenestrated capillaries and arterioles in glomerular filtration; example vascular resistance and autoregulation of blood flow; concrete body example of capillary dynamics (filtration); Renin-angiotensin mechanism 14. Chapter 26: Edema; Renal mechanism of electrolyte balance 15. Chapter 28: Varicose veins and effects on pregnancy

Copyright © 2010 Pearson Education, Inc.

229

230

Text and media guide to human anatomy and physiology

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 32: Blood vessel anatomy Exercise 33: Human cardiovascular physiology Exercise 34: Frog cardiovascular physiology PhysioEx™ 8.0 Exercise 33B: Cardiovascular dynamics: computer simulation 2. Marieb, E.N. and S.J. Mitchell . Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 32: Blood Vessel Anatomy Exercise 33: Human Cardiovascular Physiology Exercise 34: Frog Cardiovascular Physiology PhysioEx™ 8.0 Exercise 33B: Cardiovascular Dynamics: Computer Simulation

Teaching Tips 1. Emphasize the smooth transition in the wall structure from artery to arteriole, capillary, venule and vein. 2. Instead of giving a lesson solely about muscular and elastic arteries, capillaries, etc., try to describe the basic structure of the wall and ask the class what the logical functions of these vessels might be given their construction. 3. Emphasize the differences in permeability between capillary types and the specific roles that these different types must play. 4. When discussing blood flow, introduce each factor (pressure, resistance, etc.) and then number them logically so students can appreciate the dynamic nature of blood transport. Students often treat the vasculature as a rigid set of tubes. 5. Spend some time going through a series of charts that describe muscle pumping as a factor that supports venous return. Students are often confused about how this mechanism works. 6. Work on the respiratory factor, which supports venous return along with second heart sound division. Students will understand the concept more easily when the two ideas are related. 7. Emphasize the importance of vasomotor tone. Students should be aware that unless the arteries are in a constant state of partial contraction (during normal activity), there would be no mechanism that would allow vasodilation. 8. Since hypertension and its risks are of interest to most people, use the discussion in this topic to bring together important concepts about heart and vascular function and the mechanisms of blood pressure control. 9. Students often struggle with the idea that capillaries have a larger total cross-sectional area than arteries. It often helps to visualize a single artery about 5 mm in diameter and 10 to 20 capillaries about 1 mm in diameter to show the relationship between the total area and the total number of vessels. 10. A discussion of pulmonary circulation is a good place to recall the relative sizes of the left and right hearts. Describe the short path of low pressure from the right ventricle to the left atrium. 11. Some students find it difficult to see that coronary circulation is greatest when the heart muscle is in diastole. Emphasize the elastic recoil of the aorta as the driving force, i. H. the aorta stores the force of ventricular contraction in its elastic connective tissue.

Copyright © 2010 Pearson Education, Inc.

Chapter 19

The cardiovascular system: blood vessels

12. A full understanding of fluid movement at the capillary level is critical to a full understanding of how other systems work. Refer students to Chapter 3 for an overview of osmosis and emphasize that this topic will come up again in future systems. 13. Emphasize that arteries always carry blood away from the heart and veins always return blood to the heart. 14. The functioning of the cardiovascular system is easy to master when using schematic diagrams. Test the student's knowledge by asking what the possible consequences are if partial crashes occur in different parts of the system. Students must be able to describe reduced perfusion of the systemic circulation, LV hypertrophy and eventual regurgitation, mitral regurgitation, pulmonary edema, eventual venous congestion, etc. This is an excellent exercise to demonstrate the circular nature of this closed system and that effects at some point in the system are likely to be completed if left unchecked.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Demonstrate the auscultatory method of determining blood pressure and provide the necessary equipment (sphygmomanometers and stethoscopes) for students to practice on each other. 3. Ask students to name the vessels shown using a human vessel model or unlabeled acetate. 4. Use a torso model, circulatory system model, and/or stuffed animal model to show major circulatory pathways. 5. Using a short dip hose, illustrate a capillary as a functional unit of the circulatory system. 6. Use a long balloon that is not fully inflated to illustrate the effect of pressure changes in a closed system.

Critical thinking/topics for discussion 1st 2nd 3rd 4th 5th

Discuss the need to monitor blood pressure for hyper- or hypotension. Explore the importance of proper nutrition to maintain normal blood flow. Discuss why some heart bypass surgeries need to be repeated. Explain how an artery loses its elasticity. In terms of blood flow mechanics, discuss why the pulse is visible on the arterial side but not on the venous side of the circuit. 6. Describe the factors that delay venous return. 7. Explain why water and solutes leave the bloodstream at the arteriolar end of the capillary bed and enter the bloodstream at the venous end. 8. Discuss why the elasticity of the great arteries is so important (or why atherosclerosis is such a threat).

Library Research Topics 1. Examine the role of diet in clearing or blocking blood vessels. 2. Investigate possible congenital anomalies of circulation arising from differences in fetal and adult circulation. 3. To study the effect of untreated hypertension on renal function. 4. Examine the procedures and types of valves currently used in valve replacement surgery.

Copyright © 2010 Pearson Education, Inc.

231

232

Text and Media Human Anatomy and Physiology Instructor Manual 5. Explore the different types of heart blocks and what they mean. 6. Examine the risk factors involved in heart disease and what can be done to minimize the risk.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all chapter-specific online media resources for Chapter 19 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives PART 1: OVERVIEW OF THE STRUCTURE AND FUNCTION OF BLOOD VESSELS (pp. 695-703) Section 19.1 Structure of Blood Vessel Walls (p. 695) Interactive Game of 10 Physiology®: Cardiovascular System: Anatomy Review: Structure and Function of Blood Vessels Section 19.2 Arterial system (pp. 695–698) Section 19.3 Capillaries (pp. 698–700) Section 19.4 Venous system (pp. 700–701) Section 19.5 Vascular anastomoses (pp. 701, 703) PART 2: PHYSIOLOGY OF THE CIRCULATION ( p. 8.0: Cardiovascular dynamics Section 19.7 Systemic blood pressure (pp. 704-706) Physiology® Interactive 10 System Set: Cardiovascular system: blood pressure measurement Section 19.8 Blood pressure maintenance (pp. 706-713) Interactive Physiology® 10 System suite: Cardiovascular system Hat : Blood Pressure Regulation Section 19.9 Blood Flow Through Body Tissues: Tissue Perfusion (pp. 713-721) Interactive Physiolog y® 10 System Suite: Cardiovascular System: Autoregulation and Capillary Dynamics Case Study: Septic Shock PART 3: CIRCULATORY PATHWAYS: BLOOD VESSELS IN THE BODY (p. 721–745) Section 19.10 The two main circuits of the body body (p. 721) Section 19.11 Systemic arteries and veins: differences in paths and courses (p. 721)

Copyright © 2010 Pearson Education, Inc.

Chapter 19

The cardiovascular system: blood vessels

Section 19.12 Major vessels of the systemic circulation (pp. 721-745) Section 19.13 Aspects of blood vessel development (p. 745) Artist's label: Major arteries of the systemic circulation (Fig. 19.21b, p. 725) Artist's label: Arteries of the systemic circulation systemic circulation or abdomen ( Fig. 19.24b, p. 731) Artist Tagging: Main veins of the systemic circulation (Fig. 19.26b, p. 737) Chapter Summary Crossword Puzzle 19.1 Crossword Puzzle 19.2 Links Web Questionnaire of your choice True Test -Fake Chapter Test Study Tools Histology Atlas myeBook Flashcards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1st edition: Rio da Vida (IM; 28 min., 1997). This DVD shows how food and chemicals are transported through the circulatory system to and from living cells in the body. 2. Circulation: What an Autopsy Reveals (IM; 50 min, 2006). In this DVD, Gunther von Hagens and John Lee demonstrate the weaknesses and fragility of the human circulatory system. They expose the network of veins and arteries in a deceased woman's body and dissect the heart to reveal atherosclerosis and the appearance of dead heart muscle. 3. Life under Pressure (FHS; 26 min., 1984). This program follows the journey of a red blood cell through the circulatory system to demonstrate the efficient and elegant design of delivering oxygen and nutrition to all parts of the body. It shows how veins and arteries are built to do their jobs. 4. Pump Life: Cardiovascular (WNS; 20 min). Explain the structure and function of the heart using animation and live action. Discuss heart problems and the importance of preventative maintenance. 5. William Harvey and the Circulatory System (FHS; 29 mins). This program provides an introduction to the life and work of William Harvey, the English physician and Copyright © 2010 Pearson Education, Inc.

233

234

Text and media Manual of human anatomy and physiology Physiologist who discovered the circulation of blood in the human body in 1628. The program describes how Harvey formulated his revolutionary new theories of heart action and the movement of blood through the heart, arteries and veins. .

Software 1. 2. 3. 4.

5. 6.

7. 8. 9.

A.D.A.M.® Interactive Anatomy® 4.0 (see page 9 of this manual for a complete list). A.D.A.M.® MediaPro (see page 9 of this manual for a complete list). A.D.A.M.® Anatomy Practice (see page 87 of this manual for a complete list). DynaPulse™ 200M Educational (DP; Windows). It describes cardiovascular function by combining medical tools with interactive software and graphics. It provides clinical quality systolic, diastolic, MAP and heart rate measurements. LOGAL® Biology Explorer™: Cardiovascular System CD-ROM (see page 219 of this manual for a complete list). Interactive set of 10 Physiology® systems: cardiovascular system (BC; Win/Mac). Presents topics related to the physiology of the heart and blood vessels, such as blood pressure, cardiac output, the intrinsic conduction system, the cardiac action potential, and the cardiac cycle. Practice Anatomy Lab™ 2.0: Human cadaver, anatomical models, cat, fetal pig (see full list on page 9 of this guide). The Ultimate Human Body, version 2.2 (see page 9 of this guide for a full list). Physiology of the Blood and the Circulatory System CD-ROM by WARD (WNS; Win/Mac). Learn more about the components of blood and the inner workings of the human heart. Practice simulating clinical techniques like counting hematocrit, taking blood pressure, and more.

Material to improve the lesson Thumbnails of all illustrations in Chapter 19 can be found in Appendix B.

Instructor Transparency Index/Resource DVD Figure 19.1 Figure 19.2 Figure 19.3 Figure 19.4 Figure 19.5 Figure Figure Figure Figure Figure

19,6 19,7 19,8 19,9 19,10

figure figure figure figure

19,11 19,12 19,13 19,14

Figure 19.15 Figure 19.16

Generalized structure of arteries, veins and capillaries. The relationship of the blood vessels to each other and to the lymph vessels. hair texture Anatomy of a capillary bed. Relative proportion of blood volume in the entire cardiovascular system. Blood pressure in different blood vessels of the systemic circulation. The muscle pump. Main factors increasing cardiac output. Baroreceptor reflexes that help maintain blood pressure homeostasis. Direct and indirect (hormonal) mechanisms of renal blood pressure control. Factors causing an increase in MAP. Places on the body where the pulse is most easily felt. Distribution of blood flow at rest and during physical exertion. Relationship between blood flow velocity and total cross-sectional area in various blood vessels in the systemic circulation. Summary of the intrinsic and extrinsic control of arteriolar smooth muscle in the systemic circulation. capillary transport mechanisms. Copyright © 2010 Pearson Education, Inc.

Chapter 19 Figure 19.17 Figure 19.18 Figure 19.19 Figure 19.20 Figure 19.21 Figure 19.22 Figure 19.23 Figure 19.24 Figure 19.25 Figure 19.26 Figure 19.27 Figure 19.28 Figure 19.29 Figure 19.30 Table 19.1 Table 19.2 Table 19.3 Table Table 19.3

19,5 19,6 19,7 19,8 19,9

Table 19.10 Table 19.11 Table 19.12 Table 19.13 Closer Look Making Connections

The cardiovascular system: blood vessels

The liquid flows in the capillaries. Events and signs of compensated (non-progressive) hypovolemic shock. pulmonary circulation. Schematic flow diagram showing an overview of the systemic cycle. main arteries of the systemic circulation. Arteries of the head, neck and brain. Arteries of the right upper extremity and thorax. abdominal arteries. Arteries of the right pelvis and lower extremity. main veins of the systemic circulation. Venous drainage of the head, neck and brain. Veins of the thorax and right upper extremity. abdominal veins. Veins of the right lower extremity. Summary of blood vessel anatomy Influence of selected hormones on variables affecting pulmonary artery pressure and systemic circulation (Figs. 19.19 and 19.20) Aorta and major arteries of systemic circulation (Fig. 19.21) Carotid and cervical arteries (Fig. 19.22) Arteries of the upper extremities and thorax (Fig. 19.23) arteries of the abdomen (Fig. 19.24) arteries of the pelvis and lower extremities (Fig. 19.25) the vena cavae and great veins of the systemic circulation (Fig. 19.26) veins of the head and neck (Fig. 19.27) Veins of the upper extremities and thorax (Fig. 19.28) Veins of the abdomen (Fig. 19.29) Veins of the pelvis and lower extremities (Fig. 19.30) Arteriosclerosis?

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 16. Capillary anatomy lends itself to the exchange of material between blood and interstitial fluid because their walls are very thin and they lack muscle and connective tissue. (p. 698) 17. Elastic arteries are the large, thick-walled arteries near the heart. They have generous amounts of stretch fabric on all tunics but especially on the center tunic. This stretchy fabric allows them to withstand large pressure swings as they stretch.

Copyright © 2010 Pearson Education, Inc.

235

236

Text and media guide to human anatomy and physiology

18

19

20

21

22

23

24

when the heart contracts and forces the blood into them. They decrease as blood flows into the circulatory system while the heart is relaxing. They also contain significant amounts of smooth muscle but are relatively inactive in vasoconstriction. (p. 697) Muscular arteries are medium-sized and smaller arteries later in the bloodstream that carry blood to specific organs in the body. Their tunica media contains proportionally more smooth muscle and less elastic tissue than elastic arteries, but they usually have an elastic layer on each surface of the media. They are more active in vasoconstriction and less compliant. (p. 698) Arterioles are the smallest arterial vessels. The smallest, the endarterioles, directly feed the capillary beds. The largest arterioles show all three tunicas and their tunica media consists mainly of smooth muscle with some scattered elastic fibers. The walls of the smaller arterioles are little more than smooth muscle cells that wrap around the lining of the tunica intima. When arterioles contract, the tissues they serve are largely bypassed; As the arterioles dilate, blood flow to the local capillaries increases dramatically. (p. 698) The equation showing the relationship between peripheral resistance, blood flow, and arterial pressure is as follows: Blood flow is equal to a change in arterial pressure between two points in the circulation divided by the resistance. (p. 704) Blood pressure is the force per unit area exerted by the blood contained in it on the wall of a blood vessel. Systolic pressure is the pressure that occurs during systole when aortic pressure is at its peak. Diastolic pressure is the pressure that occurs during diastole when aortic pressure falls to its lowest level. (pp. 704 and 705) b. The normal blood pressure of a young adult is between 110 and 140 mm Hg systolic and between 75 and 80 mm Hg diastolic. (p. 705) The neural controls responsible for controlling blood pressure work through reflex arcs, which mainly include the following components: baroreceptors and associated afferent fibers, medullary vasomotor center, vasomotor (efferent) fibers, and vascular smooth muscle. Neural controls are primarily aimed at maintaining appropriate systemic blood pressure and altering blood distribution to perform specific functions. (pp. 706-709) Velocity changes in different areas of the circuit reflect the cross-sectional area of ​​the vessel lines to be filled. Because the cross-sectional area is smallest in the aorta and largest in the capillaries, blood flow is fastest in the aorta and slowest in the capillaries. (pp. 713-714) Blood flow to the skin with nutrients is controlled by autoregulation in response to oxygen demand, while blood flow to regulate body temperature is controlled by neural intervention, i.e. the sympathetic nervous system (pp. 716-717) If someone fleeing from an attacker, blood flow is diverted to skeletal muscles in other body systems that don't directly require large amounts of blood. Blood flow increases in response to the release of acetylcholine from sympathetic vasodilator fibers and/or the binding of epinephrine to beta-receptors of vascular smooth muscle in skeletal muscle, and virtually all capillaries open to accommodate the increased flow. Systemic adaptations, mediated by the sympathetic vasomotor center, occur to ensure that the increased blood volume reaches the muscles. The severe vasoconstriction of the digestive tract temporarily diverts blood from these regions, allowing more blood to flow to the muscles. Adrenaline in the blood increases blood sugar levels, alertness and metabolic rate. The main factor that determines how long muscles can sustain vigorous activity is the cardiovascular system's ability to deliver adequate oxygen and nutrients. (p. 716) Nutrients, waste, and respiratory gases are transported to and from the blood and tissue spaces by diffusion. (p. 717) Copyright © 2010 Pearson Education, Inc.

Chapter 19

The cardiovascular system: blood vessels

25. a. The veins that drain the digestive organs help form the hepatic portal circulation. The most important are the superior and inferior mesenteric veins and the splenic veins. B. The portal circulation is a "foreign" circulation because it consists of veins draining into capillaries, which in turn drain into the veins. (pp. 742 and 743) 26. a. The text states that postcapillary venules function "rather like capillaries" (p. 700), meaning that the exchange of small molecules between blood and surrounding tissue fluid occurs through these venules. In addition, inflammatory fluid and white blood cells leave the postcapillary venules as they exit the capillaries. B. While capillaries consist of only one endothelium, postcapillary venules have fibroblasts scattered throughout their endothelial layer.

Critical Thinking Questions and Clinical Applications 1. Ms. Johnson induces an increase in heart rate and intense vasoconstriction, which allows blood in various pools to flow rapidly into the main circulatory channels. (pp. 706-709) 2. When sympathetic nerves are transected, vasoconstriction in the area will be reduced and vasodilation will occur. Therefore, blood flow to the area is increased. (p. 695) 3. An aneurysm is a balloon-like enlargement of a blood vessel that threatens to rupture the vessel. In this case, the aneurysm was so large that it pressed against the brainstem and cranial nerves, threatening to impair the function of these structures. Surgeons removed the enlarged section of the artery and sewed a section of sturdy tubing in its place. (p. 748) 4. Harry's condition suggests a case of transient vascular shock. Walking in the intense heat of the day caused skin blood vessels to dilate, leading to an increase in blood volume in the lower limbs (due to gravity). A subsequent decrease in blood flow to the heart caused Harry's blood pressure to drop, and his dizziness and fainting spells were an indication that the brain was not getting enough blood (hence oxygen). (p. 720) 5. The blood distribution is adapted to specific requirements by a short-term neural control mechanism. During exercise, the hypothalamus sends signals to reduce vasomotor stimulation of the vessels in the skin. Blood moves into the capillary beds and heat is radiated from the skin to lower body temperature. (p. 716) 6. (1) Ms. Taylor no longer produces enough plasma proteins to maintain adequate colloid osmotic pressure in the blood vessels. (p. 718) (2) The hydrostatic capillary pressure would increase, causing more liquid to flow out of the capillaries. (p. 718) (3) The osmotic pressure of the interstitial fluid would be increased by the increase in plasma proteins. This would cause more liquid to flow out of the capillaries. (p. 718) (4) The lymphatic vessels can no longer drain from the right arm, so that fluid accumulates in the arm and swells. The compression cuff would increase the hydrostatic pressure of the interstitial fluid and reduce the amount of fluid leaking from the capillaries in the right arm. (p. 718)

Recommended Reading Carmeliet, Peter. "Creating Unique Blood Vessels". Nature 412 (6850) (2001 Aug): 868-869.

Copyright © 2010 Pearson Education, Inc.

237

238

Text and media manual for teachers of human anatomy and physiology Christensen, Damaris. "It just clicked: making stents even better at keeping arteries open." Science News 160(21) (November 2001): 328-330. Corder, R., et al. "Reduced endothelin-1 synthesis by red wine". Nature 414 (6866) (December 2001): 863. Gross, Steven S. "Targeted Delivery of Nitric Oxide." Nature 409 (6820) (February 2001): 577-578. Harder, B. "Even normal high blood pressure is too high." Science News 160(18) (November 2001): 277. Jain, Rakesh K. "Taming Vessels to Treat Cancer." Scientific American 298(1) (January 2008): 56-63. LeCouter, J., et al. "Identification of a selective angiogenic mitogen for the endothelium of the endocrine gland". Nature 412 (6850) (Aug 2001): 877–884. MARX, John. "Possible new route to blood pressure control". Science 293 (5532) (2001 August): 1030. Miller, Greg. "The nerves tell the arteries to grow like a tree." Science 296 (5571) (2002 June): 2121. Pletcher, Mark J., et al. "Prehypertension in adolescence and coronary calcium later in life". Annals of Internal Medicine 149(2) (July 2008): 91-99. Schubert, C. "Vitamin A calibrates a heart clock, 24 hours a day, 7 days a week." Science News 160(2) (2001 Jul): 22. Seydel, Caroline. "The organs await the activation signal of the blood vessels." Science 293 (5539) (2001 Sept.): 2365. Swain, David P. "The water tower analogy of the cardiovascular system." Advances in Physiology Education 24(1) (December 2000): 43-50. Taubes, Gary. “Is Inflammation Getting to the Heart of the Matter?” Science 296 (5566) (April 2002): 242–245. Travis, J. "Blood vessels (without blood) give shape to organs." Science News 160(13) (2001 Sept): 198. Wang, L. "Radiation therapy keeps the arteries clear." Science News 159(4) (2001 Jan): 184. Zhu, Yan, et al. "Abnormal vascular function and hypertension in estrogen receptor beta-deficient mice". Science 295 (5554) (January 2002): 505-508.

Copyright © 2010 Pearson Education, Inc.

The lymphatic system and the lymphatic organs and tissues

Goals

20

lymph nodes

Lymph vessels 1. Name the functions of the lymph vessels. 2. Describe the structure and distribution of the lymph vessels. 3. Describe the origin of lymph and the mechanism(s) of lymph transport. Lymphatic Cells and Tissues 4. Describe the basic structure and cell population of lymphatic tissue. Distinguish between diffuse and follicular lymphoid tissue.

5. Describe the general location, histology, and function of the lymph nodes. Other Lymphatic Organs 6. Name and describe the other lymphatic organs in the body. Compare and contrast them structurally and functionally with the lymph nodes. Developmental aspects of the lymphatic system and lymphatic organs and tissues 7. Describe the development of the lymphatic system and lymphatic organs and tissues.

Suggested Course of Lessons I. Lymphatics (pp. 753–755; Figs. 20.1–20.2) A. The lymphatics form a unidirectional system in which lymph flows only to the heart (pp. 753–754; Figs. 20.1–20.2) . 1. The lymphatic transport system begins with the lymph capillaries, which lie between the tissue cells, and the blood capillaries in the loose connective tissue. 2. The lymph capillaries flow into the lymphatic collection vessels and transport the lymph to the lymph trunks. 3. The lymphatic trunks drain relatively large areas of the body and eventually drain the lymph back into the circulatory system via the thoracic duct, or right lymphatic duct. B Lymphatics are low-pressure vessels that use the same mechanisms as veins to return lymph to the circulatory system (pp. 754-755).

II. Lymphoid Cells and Tissues (pp. 755-756; Fig. 20.3) A. Lymphoid Cells (pp. 755-756) 1. Lymphocytes originate in the red bone marrow and mature into one of two immunocompetent cells: T lymphocytes ( T -cells) or B-lymphocytes (B-cells). 2. Macrophages play an important role in protecting the body and activating T lymphocytes Copyright © 2010 Pearson Education, Inc. All rights reserved.

239

240

Text and Media Instructor's Guide to Human Anatomy and Physiology 3. Dendritic cells found in lymphoid tissue also play a role in activating T lymphocytes 4. Reticular cells produce the stroma that carries the other cell types in lymphoid tissue. B. Lymphoid tissues harbor and provide a proliferation site for lymphocytes and an ideal surveillance site for lymphocytes and macrophages (p. 756; Fig. 20.3).

3. Lymph Nodes (pp. 756-758; Fig. 20.4) A. The major lymphatic organs of the body are the lymph nodes, which act as filters to remove and destroy microorganisms and other debris from the lymph before they are returned to the Lymph is transported body bloodstream. (p. 756). B. Each lymph node is surrounded by a dense fibrous capsule with an internal structure or stroma of reticular fibers supporting lymphocytes (pp. 756-757; Fig. 20.4). C. Lymph enters the convex side of a lymph node through afferent lymphatics and exits through fewer efferents after passing through several paranasal sinuses (pp. 757-758; Fig. 20.4).

4. Other Lymphatic Organs (pp. 758-761; Figs. 20.5-20.9) A. The spleen is the largest lymphatic organ and is located on the left side of the abdominal cavity just below the diaphragm (p. 758; Figs. 20.5-20.6 ). 1. The main function of the spleen is to remove old and defective red blood cells and platelets, as well as foreign objects and debris from the blood. It also provides a site for lymphocyte proliferation and immune surveillance. 2. The spleen is surrounded by a fibrous capsule and contains lymphocytes in the white pulp and macrophages in the red pulp. B. Thymus (pp. 759-760; Figs. 20.5, 20.7) 1. The thymus secretes hormones that render T lymphocytes immunocompetent. 2. The thymus consists of thymus lobes containing an outer cortex and an inner medulla. C. The tonsils are the simplest of the lymphoid organs and form a ring of lymphoid tissue around the pharyngeal opening. They appear as mucosal swellings that accumulate and eliminate many of the pathogens that enter the throat via food or air (p. 760; Figs. 20.5, 20.8). D. Groups of lymphoid follicles are found in the wall of the distal small intestine, Peyer's patches, and the cecum (pp. 760-761; Figs. 20.5, 20.9).

V. Developmental Aspects of the Lymphatic System and Lymphoid Organs and Tissues (p. 761) A. In the fifth week of embryonic development, the onset of lymphatic vessels and large clusters of lymph nodes are evident and develop from the lymphatic sacs. to the development of veins (p. 761). B. The thymus is an endodermal derivative, while the other lymphoid organs are derived from the mesoderm (p. 761). C. With the exception of the spleen and tonsils, the lymphatic organs are poorly developed at birth (p. 761).

Copyright © 2010 Pearson Education, Inc.

Chapter 20

The lymphatic system and the lymphatic organs and tissues

Cross-references For more information on the topics covered in Chapter 20, see the chapters listed below. 1st 2nd 3rd 4th 5th

Chapter 3: Interstitial Fluid Chapter 4: Reticular Connective Tissue Chapter 16: Thymus Gland and Hormone Production Chapter 17: Agranulocytes; granulocytes; Leukocyte Production and Life Expectancy Chapter 19: Blood Capillaries; hydrostatic and osmotic pressures related to fluid movement; Factors supporting venous return 6. Chapter 21: Role of the lymphatic organs in immunity; relationship of the thymus to cell-mediated immunity 7. Chapter 22: Tonsils 8. Chapter 23: Lactic acid function; tonsils; Lymphatic tissue associated with the digestive system (Peyer's patches)

Teaching Tips 1. Emphasize the difference between lymph capillaries and blood capillaries. Students often ask the question: "Since both are capillaries, why does interstitial fluid flow from blood capillary to lymph capillary?" 2. Point out that the same factors that support venous return also support lymphatic movement. Because blood and vessels are structurally similar and follow the same general paths, logic dictates that the factors affecting their fluid movements must also be similar. 3. Mention that lumps (swollen lymph nodes) are the "swollen glands" that appear with infectious processes. 4. Point out that the structure and location of the lymph nodes are ideal for filtering interstitial fluid (which contains tissue proteins, metabolic waste, and pathogenic microorganisms) released from the tissue spaces.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Use a torso model and/or dissected animal model to show the lymphoid organs. 3. Use a visual aid showing a person with elephantiasis to illustrate the swelling that results from blocked lymphatics. 4. Poll the class to determine how many students have had their tonsils removed. Explain that in the 1950's tonsillectomy was a routine operation and almost 100% of children in North America had their tonsils removed. In the 1960s, this operation was recognized as unnecessary.

Critical Thinking/Discussion Points 1. Explain why and how lymphedema occurs after modified radical mastectomy or similar surgery. 2. State the reason a doctor examines the neck for swollen lymph nodes when examining a patient with respiratory symptoms. 3. Examine the effects of removing the spleen. 4. Examine the effects of removing tonsil tissue. 5. Briefly describe the role of the thymus gland in the body's immune response.

Copyright © 2010 Pearson Education, Inc.

241

242

Text and media guide to human anatomy and physiology

Library Research Topics 1. Research the causes, effects, and treatment of lymphedema. 2. Examine the differences between lymph nodes that are due to a disease, e.g. a viral infection, and those swollen due to cancer. 3. Examine the changes that occur in the thymus gland with age and relate these changes to the body's immune response.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all chapter-specific online media resources for Chapter 20 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Targets Section 20.1 Lymphatic Vessels (pp. 753–755) Artist's Caption: The Lymphatic System (Fig. 20.2a, p. 755) Section 20.2 Lymphoid Cells and Tissues (pp. 755–756) Section 20.3 Lymph Nodes (pp. 756–758) ) Labeled Art: Lymph Nodes (Fig. 20.4a, p. 757) Section 20.4 Other Lymphatic Organs (pp. 758–761) Memory Game: The Immune System Memory Game: Important Components of the Immune System Section 20.5 Aspects of the System Development of Lymphatic and Lymphatic Organs and Tissues ( p. 761) Case Study: Genetic Immune Deficiency Chapter Summary Crossword 20.1 Web Links Chapter Quizzes Artistic Labeling Quiz Combination Quiz Multiple Choice Quiz True-False Quiz Chapter Quiz Tools Study Histology Atlas myeBook Flashcards Glossary

Copyright © 2010 Pearson Education, Inc.

Chapter 20

The lymphatic system and the lymphatic organs and tissues

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1. Home Defenses (FHS; 28 min, 1984). This show from The Living Body series is about the events that occur when the body is attacked. Shows the functions of the spleen, the lymphatic system and the white blood cells and explains the body's own production of antibodies. 2. Video organ systems work together (WNS; 14 min). Provides an overview of the body's systems and how they work together. Introduces the student to the functions of the human body.

A.D.A.M.® Interactive Anatomy® 4.0 software (see full list on page 9 of this manual). A.D.A.M.® MediaPro (see page 9 of this manual for a complete list). A.D.A.M.® Anatomy Practice (see page 87 of this manual for a complete list). Practice Anatomy Lab™ 2.0: Human cadaver, anatomical models, histology (see full list on page 9 of this guide). 5. The Ultimate Human Body, version 2.2 (see page 9 of this manual for the full list).

1. 2. 3. 4.

Materials to Improve Teaching Thumbnails of all figures in Chapter 20 can be found in Appendix B.

Figure 20.1 Figure 20.2 Figure 20.3 Figure 20.4 Figure 20.5 Figure 20.6 Figure 20.7 Figure 20.8 Figure 20.9 Make connections

Distribution and special structural features of the lymphatic capillaries. The Lymphatic System. Reticular tissue in a human lymph node. lymph nodes. lymphatic organs. the spleen Excellent. Histology of the palatine tonsil. Peyer patch. System Connections: Homeostatic interrelationships between the lymphatic/immune system and other body systems

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Copyright © 2010 Pearson Education, Inc.

243

244

Text and media guide to human anatomy and physiology

Short Answer Essay Questions 10. Blood, the carrier of nutrients, waste, and gases, circulates in the body's blood vessels and exchanges materials with interstitial fluid. Interstitial fluid, formed by the filtration of blood, is the fluid that surrounds the body's cells in the tissue spaces and is essential for protein-free plasma. Lymph is the proteinaceous fluid that enters the lymphatic capillaries (from the tissue spaces); hence its composition is the same as that of the interstitial fluid. (p. 753) 11. Lymph nodes are very small, bean-shaped structures made up of the medulla and cortex that act as filters to clean the lymph before it can re-enter the blood. Each node is surrounded by a dense fibrous capsule from which strands of connective tissue called trabeculae extend to divide the node into multiple compartments. The basic internal structure or stroma is an open network of reticular fibers that provide physical support for lymphocytes and macrophages. The outer cortex contains densely packed globular collections of lymphocytes called follicles, which often have lighter colored centers called germinal centers. Cord-like extensions of the cortex, called medullary cords, penetrate the medulla. Macrophages are found throughout the nodule but are particularly abundant in the lining of the medullary cavities. (pp. 756-757) The spleen is the largest lymphatic organ. It removes old or defective blood cells, platelets, and pathogens from the blood and stores or releases some of the red blood cell breakdown products into the blood for processing by the liver. The spleen is surrounded by a fibrous capsule and has trabeculae. Contains lymphocytes, macrophages and a large number of erythrocytes. Venous sinuses and other regions that contain red blood cells and macrophages and process blood are called the red pulp, while areas composed primarily of lymphocytes suspended in reticular fibers are called the white pulp. Inside the organ, the white pulp is grouped around small branches of the splenic artery and serves the organ's immune functions. (p. 758) 12. a. The anatomical feature that ensures the slow passage of lymph through a lymph node is the fact that there are fewer efferent vessels draining the lymph node than there are afferent vessels supplying it. (p. 757) b. This feature is desirable to allow time for lymphocytes and macrophages to carry out their protective functions. (p. 757) 13. Lymph is generated in body tissues and only returns to the heart, so there is no need for arteries to carry lymph out of the heart. (p. 754)

Critical Thinking Problems and Clinical Application 1. a. By removing the lymph vessels, fluid collects in the tissue and drains very slowly into the bloodstream. B. Yes, you can expect relief; Lymphatic drainage is eventually restored by the growth of lymphatic vessels. (pp. 754-755) 2. Your swollen "glands" are swollen cervical lymph nodes. The bacteria spread through the lymphatic vessels that drain the incised area of ​​the face and lodge in the lymph nodes of the neck, infecting those nodes. (See Fig. 20.2.) 3. These lymphoid organs play a role in the generation, control and enhancement of the immune response. (pp. 758, 760)

Copyright © 2010 Pearson Education, Inc.

Chapter 20

The lymphatic system and the lymphatic organs and tissues

Suggested Reading Keen, D.C. "Noncancerous lymphedema of the lower extremity". Nursing Standard 22(24) (February 2008): 53–61. Mayerson, HS "The Lymphatic System." Scientific American (June 1963): 158. Srent, J. and D.F. Tough. "Memory and Lifespan of Lymphocytes". Science 265 (September 1994): 1395–1400. Thorbecke, GJ, et al. "Biology of the germinal centers in lymphoid tissue". FASEB Journal 8 (1994 August): 832-840. Waldmann, T.A. "T cell receptors for cytokines: targets for leukemia/lymphoma immunotherapy." Annals of Oncology 11, Supplement 1 (2000): 101-106. Whitman, M. "Prevention of Lymphedema, an Undesirable Consequence of Breast Cancer." Nursing 93 (December 1993): 36–39. Yang, K., et al. "Do the germinal centers play a role in the development of lymphoma?" Current problems in microbiology and immunology 246 (1999): 53–62.

Copyright © 2010 Pearson Education, Inc.

245

21

The immune system: innate and adaptive body defenses

Goals

humoral immune response

PART 1: INNATURAL DEFENSE Surface barriers: skin and mucosa 1. Describe the surface membrane barriers and their protective functions. Internal defenses: cells and chemicals 2. Explain the importance of phagocytosis and natural killer cells in the body's innate defenses. 3. Describe the inflammatory process. Identify several flammable chemicals and state their specific functions. 4. Name the antimicrobial substances in the body and describe their function. 5. Explain how fever protects the body. PART 2: ADAPTIVE DEFENSE Antigens 6. Define antigen and describe how antigens affect adaptive defence. 7. Define full antigen, hapten and antigenic determinant. Cells of the adaptive immune system: an overview 8. Comparison and contrast of origin, maturation process and general function of B and T lymphocytes 9. Define immune competence and self-tolerance and describe their development in B and T lymphocytes T. Different antigenic presenting cells and describe their role in adaptive defence.

11. Define humoral immunity. 12. Describe the process of clonal selection of a B cell. 13. Describe the functions of plasma cells and memory cells in humoral immunity. 14. Compare and distinguish active and passive humoral immunity. 15. Describe the structure of an antibody monomer and name the five classes of antibodies. 16. Explain the function(s) of antibodies and describe the clinical applications of monoclonal antibodies. Cell-mediated immune response 17. Follow the processing of antigens in the body. 18. Define cell-mediated immunity and describe the process of clonal selection and activation of T cells 19. Describe the functions of T cells in the body. 20. List the tests required before performing an organ transplant and the methods used to prevent transplant rejection. Homeostatic imbalance of immunity 21. Give examples of immunodeficiency diseases and hypersensitivity conditions. 22. List the factors involved in autoimmune diseases. Developmental aspects of the immune system 23. Describe the changes in immunity that occur with age. 24. Briefly describe the role of the nervous system in regulating the immune response.

246 Copyright © 2010 Pearson Education, Inc.

Chapter 21

The immune system: innate and adaptive body defenses

Suggested Chapter Outline PART 1: CONGENITAL DEFENSE (pp. 767–775; Figs. 21.1–21.6; Tables 21.1–21.2) I. Surface barriers: skin and mucosa (pp. 767–768) A. Skin, a highly keratinized epithelial membrane, it represents a physical barrier to most microorganisms and their enzymes and toxins (p. 767). B. Mucous membranes line all body cavities open to the outside and act as an additional physical barrier (p. 768). C. Secretions from epithelial tissue include acid secretions, sebum, hydrochloric acid, saliva and mucus (p. 768).

II. Internal Defenses: Cells and Chemicals (pp. 768–775; Figs. 21.2–21.6; Boxes 21.1–21.2) A. Phagocytes are confronted with microorganisms that breach external barriers (p. 768; Fig. 21.2). 1. Macrophages are the most important scavenger cells in the body. 2. Neutrophils are the first to respond and become phagocytic when encountering infectious material. 3. Eosinophils are weakly phagocytic but important in the body's defense against parasitic worms. 4. Mast cells have the ability to bind, ingest, and kill a variety of bacteria. B. Natural killer cells are able to lyse and kill cancer cells and virus-infected cells before the adaptive immune system is activated (pp. 768-769). C. Inflammation occurs whenever body tissues are damaged by physical trauma, intense heat, irritating chemicals, or viral, fungal, or bacterial infection (pp. 769-773; Figs. 21.3-21.4; Table 21.1). 1. The four cardinal signs of acute inflammation are redness, warmth, swelling and pain. 2. The chemicals cause the surrounding blood vessels to dilate to increase blood flow to the area and increase permeability, allowing fluids containing clotting factors and antibodies to penetrate the tissue. 3. Shortly after the inflammation, the damaged site is invaded by neutrophils and macrophages. D. Antimicrobial proteins augment innate defenses by directly attacking microorganisms or preventing their ability to reproduce (pp. 773–775; Figs. 21.5–21.6; Table 21.2). 1. Interferons are small proteins produced by virus-infected cells that help protect surrounding healthy cells. 2. Complement refers to a group of approximately 20 plasma proteins that are an important mechanism for destroying foreign pathogens in the body. E. Fever, or an abnormally high body temperature, is a systemic response to microorganisms (p. 775).

PART 2: ADAPTIVE DEFENSES (pp. 775–799; Figs. 21.7–21.22) III. Antigens (pp. 775-777; Fig. 21.7) A. Aspects of the adaptive immune response (pp. 775-776) 1. Adaptive defense recognizes and destroys the specific antigen that elicited the response.

Copyright © 2010 Pearson Education, Inc.

247

248

Text and Media Human Anatomy and Physiology Teacher's Guide 2. The immune response is a systemic response; it is not limited to the original site of infection. 3. After an initial exposure, the immune response can recognize the same antigen and launch a faster and stronger defensive attack. 4. Humoral immunity is provided by antibodies produced by B lymphocytes present in the "juices" or body fluids. 5. Cellular immunity is associated with T lymphocytes and has living cells as a protective factor. B. Antigens are substances that can mobilize the immune system and provoke an immune response (pp. 776-777; Fig. 21.7). 1. Whole antigens can stimulate the proliferation of lymphocytes and specific antibodies, and react with activated lymphocytes and antibodies produced. 2. Haptens are incomplete antigens that are unable to stimulate the immune response, but when they interact with endogenous proteins, they can be detected as potentially harmful. 3. Antigenic determinants are a specific part of an antigen that is immunogenic and binds to free antibodies or activated lymphocytes.

4. Cells of the adaptive immune system: overview (p. 777-780; Fig. 21.8-21.10) A. Lymphocytes originate from the bone marrow and after their release are in the thymus (T cells) or in the bone marrow (B cells) (p. 777–778; Figs. 21.8–21.9). B. Antigen-presenting cells engulf antigens and present fragments of these antigens on their surfaces where they can be recognized by T cells (pp. 779-780; Figs. 21-10).

V. Humoral Immune Response (pp. 780-786; Figs. 21.11-21.15; Box 21.3) A. The immunocompetent but naïve B cell is activated when antigens bind to its surface receptors (p. 780; Fig. 21.11). 1. Clonal selection is the process of growth and multiplication of B cells to form an army of cells capable of recognizing the same antigen. 2. Plasma cells are the antibody-secreting cells of the humoral response; Most clones become plasma cells. 3. Clones that do not become plasma cells become memory cells. B. Immunological memory (pp. 780-781; Fig. 21.12) 1. The primary immune response occurs after the first contact with a specific antigen with a delay of about 3 to 6 days. 2. The secondary immune response occurs when someone is re-exposed to the same antigen. It's faster, longer and more effective. C. Active and passive humoral immunity (pp. 781-783; Fig. 21.13) 1. Active immunity occurs when the body mounts an immune response to an antigen. a. Naturally acquired active immunity occurs when a person suffers from the symptoms of an infection. B. Artificially acquired active immunity occurs when a person receives a vaccine.

Copyright © 2010 Pearson Education, Inc.

Chapter 21

The immune system: innate and adaptive body defenses

2. Passive immunity occurs when a person receives preformed antibodies. a. Naturally acquired passive immunity occurs when maternal antibodies enter the fetal circulation. B. Artificially acquired passive immunity occurs when a person receives preformed antibodies taken from another person. D. Antibodies or immunoglobulins are proteins secreted by plasma cells in response to an antigen capable of binding to that antigen (pp. 783-786; Figs. 21.14-21.15; Table 21.3). 1. The basic structure of the antibody consists of four looped polypeptide chains held together by disulfide bonds. 2. Antibodies are divided into five classes based on their structure: IgM, IgG, IgA, IgD and IgE. 3. Embryonic cells contain a few hundred gene segments that are shuffled and combined to make all of the different B cells found in the body. 4. Targets and Functions of Antibodies a. Complement fixation and activation occurs when complement binds to antigen-bound antibodies and leads to cell lysis. B. Neutralization occurs when antibodies block specific sites on viral or bacterial exotoxins, causing them to lose their toxic effects. C. Agglutination occurs when antibodies bind to antigens on cells and cause clumps to form. i.e. Precipitation occurs when soluble molecules crosslink into large complexes that fall out of solution. 5. Monoclonal antibodies are commercially produced antibodies specific for a single antigenic determinant.

SEEN. Cell-mediated immune response (pp. 786-795; Figs. 21.16-21.21; Boxes 21.4-21.5) A. The stimulus for clonal selection and differentiation of T cells is antigen binding, although their recognition mechanism differs from that of T cells B cells (pp. 786-791; Figs. 21.16-21.18; Table 21.4). 1. T cells have to carry out a double recognition process: They have to recognize themselves (an MHC protein from a body cell) and foreign (antigen) at the same time. 2. Activation of T Cells a. Step 1: T cell antigen receptors (TCRs) bind to an antigen-MHC complex on the surface of a cell in the body. B. Step 2: A T cell must recognize one or more costimulatory signals. C. Once activated, a T cell enlarges and multiplies to form a clone of cells that differentiate and perform functions appropriate to their T cell class 3. Cytokines comprise hormone-like glycoproteins released by macrophages and activated T cells . B. Specific functions of T cells (pp. 791–792; Figs. 21.19–21.21; Table 21.5) 1. Helper T cells stimulate the proliferation of other T cells and B cells that have already bound antigen. 2. Cytotoxic T cells are the only T cells that can directly attack and kill other cells that have the antigen to which they have been sensitized.

Copyright © 2010 Pearson Education, Inc.

249

250

3. Regulatory T cells release cytokines that suppress the activity of B cells and other types of T cells 4. Gamma-delta T cells are found in the gut and most closely resemble NK cells T cells 5 Without helper T cells, there is no adaptive immune response because helper T cells direct or help complete the activation of all other immune cells. C. Organ Transplantation and Rejection Prevention (pp. 792-795) 1. Transplants a. Autografts are tissue grafts that are transplanted from one body part to another in the same person. B. Isografts are transplants given to a patient from a genetically identical individual, e.g. B. an identical twin, can be donated. C. Allografts are transplanted grafts from individuals who are not genetically identical but belong to the same species. i.e. Xenografts are transplants taken from another species of animal. 2. The success of the transplant depends on the similarity of the tissue as the cytotoxic T cells, the NK cells and the antibodies work to destroy the foreign tissue.

VIII. Homeostatic Imbalance of Immunity (pp. 795-799; Fig. 21.22) A. Immunodeficiency is any congenital or acquired condition that causes immune cells, phagocytes or complement to behave abnormally (pp. 796-797) . 1. Severe Combined Immunodeficiency (SCID) is a congenital disorder that results in a deficiency of B and T cells 2. Acquired Immunodeficiency Syndrome (AIDS) compromises the immune system by interfering with helper T cells. B. Autoimmune diseases occur when the immune system loses its ability to distinguish between self and non-self and eventually breaks down (p. 797). C. Hypersensitivity results from the immune system causing tissue damage in response to an otherwise perceived harmless threat (pp. 797-799; Fig. 21.22). 1. Immediate hypersensitivity or allergy starts seconds after contact and lasts about half an hour. 2. Subacute hypersensitivity occurs after 1-3 hours and lasts 10-15 hours. 3. Delayed hypersensitivity reactions appear after 1-3 days and may take weeks to resolve.

VIII. Developmental Aspects of the Immune System (p. 799) A. Embryological Development (p. 799) 1. Stem cells of the immune system arise in the liver and spleen during weeks 1-9 of embryonic development; later the bone marrow takes over this role. 2. Late in fetal life and shortly after birth, young lymphocytes develop self-tolerance and immunocompetence. B. Later in life, our immune system becomes less efficient and efficient (p. 799).

Copyright © 2010 Pearson Education, Inc.

Chapter 21

The immune system: innate and adaptive body defenses

Cross-references For more information on the topics covered in Chapter 21, see the chapters listed below. 1st 2nd 3rd 4th 5th 6th 7th 8th

Chapter 2: Protein Structure Chapter 3: Cilia; Lysosomes Chapter 5: Mechanical and chemical protection of the skin; epidermal dendritic cells Chapter 15: Lysozyme Chapter 16: Thymus Chapter 17: Granulocytes; agranulocytes; chemotaxis; Diapedesis Chapter 22: Inflammatory processes affecting respiratory tissue Chapter 23: Protection of the gastric mucosal barrier; role of saliva in protecting mucosal barriers; Kupffer cells 9. Chapter 24: Regulation of body temperature 10. Chapter 28: Protection of fetal antibodies by maternal antibodies

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 35: The Lymphatic System and the Immune Response 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 35: The Lymphatic System and the Immune Response

Tips for Lesson 1. Although specific and nonspecific defenses are treated as separate entities, emphasize that there is much overlap in functionality. For example, in antibody-mediated lysis of complement, the formation of the antibody that marks a cell occurs as a result of specific processes, but the actual lysis of that cell is achieved non-specifically through complement fixation. 2. Point out that the body has multiple lines of defense: mechanical, chemical, and cellular. It is helpful to get students to think that the immune system, despite its complexity, has one underlying theme: ridding the body of unwanted substances/life forms. 3. Students often have difficulty deciding which mechanisms are specific and which are nonspecific. Emphasize that the immune system tailors its response to each individual antigen, while non-specific mechanisms respond to much broader signals. 4. Emphasize the logic behind the four cardinal signs of inflammation. For example, in order to bring large amounts of oxygen and nutrients into repair processes, an area's blood supply must be increased. Flush occurs when vasodilation increases; heat when warm blood is released; swelling as the walls of the capillaries become more permeable; pain-like pressure from swelling is transmitted to the nerve endings. 5. Point out that neutrophils are seen in the early stages of infection, but macrophages are characteristic of chronic infections. 6. To illustrate the effect of pyrogens on the hypothalamus, use the example of resetting the thermostat to a higher temperature in a house. As always, connecting a physiological concept to something the students are familiar with will help reinforce the idea. Copyright © 2010 Pearson Education, Inc.

251

252

Text and Media Human Anatomy and Physiology Instructor Manual 7. Mention that cytotoxic T cells need to be in contact with the invader, but B cells send antibodies from sometimes remote locations to attack specific antigens. 8. Highlight the difference between antigens and haptens, and this quantity is the difference between them. Basically, a hapten can be thought of as an antigenic determinant when bound to a carrier molecule; alternatively, if an antigenic determinant were not part of a large molecule, it would be a hapten. 9. To support the idea of ​​clonal selection, point out that a single B cell might not produce enough antibody to neutralize a large amount of antigen. 10. Emphasize the difference between active and passive immunity and that the body doesn't care where the antibodies come from. As students understand the concept, the question should be asked, "Why don't foreign antibodies elicit a response in the recipient?" If no one asks, ask the class to start a discussion. 11. In the supplemental discussion, ask the class, “What would happen if an antibody attached to a perfectly normal cell in the body?” Use it as an introduction to the subject of antibody constant region complement recognition. 12. It is often difficult for students to understand the concept of somatic recombination in the generation of antibody diversity. Ask plenty of questions during the lecture to reinforce concepts. 13. Clearly distinguish the different types of allergies. As the material is covered, ask students which arm of the immune system is responsible for what type of hypersensitivity: immediate, subacute, or delayed. Students must be able to make the connection that a cell-mediated response takes time (delayed hypersensitivity).

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. To open a discussion about the inflammatory process, ask if anyone has a healing cut or wound. If this is the case, ask the students observing to describe any obvious signs and the underlying reason for the signs seen. 3. Ask the students to come prepared to discuss the following questions during a later lesson: a. Explain why vaccination provides long-term protection against a specific disease while passive immunization provides only temporary protection. B. What is the important difference between natural killer cells and cytotoxic T cells? C. Why can T-helper cells be called "managers" of the immune system? 4. Use a lock and several keys (only one of which fits in the lock) to demonstrate antigen and antibody specificity.

Critical Thinking/Discussion Points 1. Discuss the pros and cons of using vaccines for mumps, measles, etc. 2. Research autoimmune diseases, how they occur, symptoms, prognosis and treatment. 3. Discuss why some people are sensitive (allergic) to medicines from one source but not as sensitive to medicines from another source. 4. Discuss the social impact of immune diseases such as AIDS, ARC, SCID, etc. Copyright © 2010 Pearson Education, Inc.

Chapter 21

The immune system: innate and adaptive body defenses

5. Identify the role of Epstein-Barr virus in immunity and immune disorders. 6. Discuss the impact of AIDS on both an immunological and social level. 7. Explain why we need specific resistance mechanisms when non-specific resistance mechanisms attack all foreign substances (ie why is specific resistance necessary?). 8. Explain the body's immune response to an antitoxin or other passive immunization. 9. Discuss why monoclonal antibody-linked chemotherapeutic agents represent an advantage over injection of the chemical agent alone. Could there be any downsides to this therapy?

Library Research Topics 1st 2nd 3rd 4th 5th

Explore some of the opportunistic infections commonly associated with AIDS. Study the difficulties associated with transplant operations. Explore the causes of several well-known autoimmune diseases. Review the signs, symptoms, and treatment for anaphylactic shock. Investigate possible side effects of vaccines.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all chapter-specific online media resources for Chapter 21 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. MP3 Teacher Session Objectives: Differences Between Innate and Adaptive Immunity Interactive Physiology 10 Systems Set: Immune System: Overview Interactive Physiology 10 Systems Set: Immune System: Review of Anatomy PART 1: INTERNAL DEFENSE 10 Systems Interactive Physiology ® Set: Host innate defenses Section 21.1 Superficial barriers: skin and mucosa (pp. 767–768) Section 21.2 Internal defenses: cells and chemicals (pp. 768–775) Artist's caption: phagocytosis (Fig. 21.2b, p. 769) Artist's caption : Mobilization of Phagocytes (Fig. 21.4 , p. 771) PART 2: ADAPTIVE DEFENSE Section 21.3 Antigens (pp. 776-777) Section 21.4 Cells of the Adaptive Immune System: Overview (pp. 777-780) Interactive Physiology® 10 System Suite : Common Features of B and T Lymphocytes Section 21.5 Humoral Immune Response (pp. 780–786)

Copyright © 2010 Pearson Education, Inc.

253

254

Text and Media Teacher's Guide to Human Anatomy and Physiology Physiology® Interactive Systems Set of 10: Humoral Immunity Artist's Labeling: Mechanisms of Antibody Actions (Fig. 21.15, p. 785) PhysioEx™ 8.0: Serological Tests Section 21.6 Immune Response Cell-Mediated Immunity ( p. 786– 795) Physiology® Interactive Systems Set of 10: Cellular Immunity Memory Game: The Immune Response, Part 1 Memory Game: The Immune Response, Part 2 Section 21.7 Homeostatic Immunity Unbalances (p. 795 ) –799) Case Study : Genetic Immune Deficiency Section 21.8 Aspects of the development of the immune system (p. 799) Chapter summary Crossword 21.1 Crossword 21.2 Crossword 21.3 Web links Chapter Quiz Art Labeling Quiz Multiple-choice matching quiz Practice test Chapter Aids Histology Atlas myeBook Flashcards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1. AIDS: A Biological Perspective (FHS; 30 min, 1995). Award-winning video examining many of the difficult issues surrounding AIDS, including discussing a vaccine. 2. Video Body against Disease (WNS; 48 min.). It provides a detailed picture of how the body defends itself against disease. Students take an in-depth look at the immune system, emphasizing the many ways it protects the body from disease. 3. Cell Wars (FHS; 22 mins). This program explains the role of antibodies in vaccines and allergies and demonstrates the use of monoclonal antibodies in the diagnosis and treatment of many different types of tumors.

Copyright © 2010 Pearson Education, Inc.

Chapter 21

The immune system: innate and adaptive body defenses

4. Human immune system (IM; 20 min, 2002). Explain how the immune system defends the body against foreign invaders. 5. Immunizations (FHS; 20 min, 1994). Explains the need for vaccination against diseases and lists the recommended vaccination schedule for children. 6. The immune system (FHS; 20 min, 2001). It shows the human immune system and what it does to keep the body healthy.

Software 1. Blood and Immunity (see full list on page 208 of this manual). 2. Interactive Set of 10 Physiology® Systems: Immune System (BC; Win/Mac). Interactive software exploring the physiology of the immune system.

For material to improve the lesson Thumbnails of all illustrations in Chapter 21, see Appendix B.

Instructor Resource DVD/Overhead Slides Image Image Image Image Image Image Image Image Image Image Image

21,1 21,2 21,3 21,4 21,5 21,6 21,7 21,8 21,9 21,10 21,11 21,12 21,13 21,14 21,15 21,16

Figure 21.17 Figure 21.18 Figure 21.19 Figure 21.20 Figure 21.21 Figure 21.22 Table 21.1 Table 21.2 Table 21.3 Table 21.4 Table 21.5

Overview of innate and adaptive defenses. phagocytosis. Inflammation: flowchart of events. Mobilization of phagocytes. The mechanism of interferon against viruses. Plugin Activation. Most antigens have several different antigenic determinants. lymphocyte trafficking. T cell formation in the thymus. dendritic cells. Clonal selection of a B cell Primary and secondary humoral responses. Active and passive humoral immunity. antibody structure. Mechanisms of action of antibodies. Major types of T cells shown based on cell differentiation glycoproteins (CD4, CD8). Processing and visualization of MHC proteins and antigens. Clonal selection of cells involves the simultaneous recognition of self and non-self. The central role of helper T cells in mobilizing humoral and cellular immunity. Cytotoxic T cells attack infected and cancer cells. Simplified summary of the primary immune response. Mechanism of an acute allergic reaction (immediate hypersensitivity). Inflammatory chemicals Overview of the body's defenses Immunoglobulin classes Selected cytokines Adaptive immune response Cells and molecules

Copyright © 2010 Pearson Education, Inc.

255

256

Text and media guide to human anatomy and physiology

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 13. Mucosa is found on the outer surface of the eye and in the lining of all body cavities that are open to the outside, such as the digestive, respiratory, urinary, and reproductive tracts. The epidermis is the outermost covering of the body's surface. The slime provides a sticky mechanical barrier that traps pathogens. Lysozyme, an enzyme that destroys bacteria, is found in saliva and tears. Keratin, a robust hydrophobic protein in epithelial membranes, provides a physical barrier to microorganisms on the skin. It is resistant to most weak acids and bases, as well as bacterial enzymes and toxins. The acidic pH of skin secretions inhibits bacterial growth. Vaginal secretions and urine (usually) are also very acidic. Hydrochloric acid is secreted by the gastric mucosa and serves to kill pathogens. Cilia on the lining of the upper airways sweep dust and bacteria-laden mucus toward the mouth, preventing it from entering the lower airways. (pp. 767-768) 14. Phagocytosis attempts are not always successful, since the feeding cell must first adhere to the particle in order to be able to take it up. Complement proteins and antibodies coat the foreign particles and provide binding sites for phagocytes to bind to, making phagocytosis more efficient. (p. 768) 15. The term complement refers to a heterogeneous group of at least 20 plasma proteins that normally circulate in an inactive state. Complement is activated by one of two pathways (classical or alternative) involving plasma proteins. Each pathway involves a cascade in which complement proteins are activated in an ordered sequence, leading to cleavage of C3. Once C3b binds to the target cell surface, it enzymatically initiates the remaining steps of complement activation, which incorporates C5 through C9 (MAC) into the target cell membrane and ensures target cell lysis. Other complement functions include opsonization, inflammatory effects such as stimulating mast cells and basophils to release histamine (increasing vascular permeability), and attracting neutrophils and other inflammatory cells to the area. (pp. 774 and 775) 16. Interferons are secreted by virus-infected cells. They spread to neighboring cells, where they interfere with the virus' ability to multiply in those cells. Cells that make interferon include macrophages, lymphocytes, and other white blood cells. (pp. 773-774) 17. Humoral immunity is provided by antibodies in body fluids. Cell-mediated immunity is provided by lymphocytes that do not produce antibodies, ie, T cells (p. 776) 18. Cytokines released by helper T cells help to enhance and regulate humoral, cellular, and innate immune responses. defend. (p. 791-792) 19. Immunocompetence is the ability of cells of the immune system to recognize foreign substances (antigens) by binding to them. Acquisition is signaled by the appearance of a unique type of cell surface receptor protein on each T or B cell that enables the lymphocyte to recognize and bind to a specific antigen. (p. 777) 20. A primary immune response results in cell proliferation, differentiation of memory and mature effector lymphocytes, and synthesis and release of antibodies, a series of events lasting 3-6 days. The secondary immune response results in large numbers of antibodies flooding the bloodstream within hours. Copyright © 2010 Pearson Education, Inc. All rights reserved.

Chapter 21

21

22

23

24

25

26

27

28

29

The immune system: innate and adaptive body defenses

after antigen recognition, as well as increased cell attack. Secondary reactions are faster because the immune system has been primed for the antigen and a significant number of sensitized memory cells are already present. (pp. 780-781) Antibodies are proteins secreted by plasma cells in response to and capable of binding to a specific antigen. See illustration. 21.14 for the basic structure of the antibody. (p. 783) The variable region of an antibody is the part of the antibody that binds to various antigens. For each different antigen there is a different variable region. The antibody constant region is used to separate antibodies into different classes. There are only five different constant regions, and all members of a specific class of antibodies share the same constant region. (p. 783) Classes of antibodies and their likely locations in the body include the following: IgD class - almost always binds to B cells; B cell receptor IgM class: monomer bound to B cells; Plasma-free pentamer (during primary response) IgG class - in plasma IgA class - some in plasma, mainly in secretions such as saliva, tears, intestinal juices and milk IgE class - secreted by plasma cells in the skin, the mucous membranes of the gastrointestinal tract -Tract, airways, and tonsils (p. 784; Box 21.3) Antibodies help defend the body by fixing, neutralizing, agglutinating, and precipitating complement. Complement fixation and neutralization are the most important to protect the body. (pp. 784-785) Vaccines produce active humoral immunity because most contain killed or extremely weakened pathogens that have the necessary antigenic determinants to stimulate the immune response, but are generally incapable of causing disease. Passive immunity is less than satisfactory because there is neither active antibody production nor immunological memory established. (pp. 781-782) Activation of CD4 cells involves both antigen binding and costimulation. CD4 cells only bind antigen bound to MHC class II proteins normally found on the surface of antigen presenting cells (APCs). Before a CD4 cell can proliferate and form clones, it must recognize one or more costimulatory signals; This involves binding to another surface receptor on the APC and receiving cytokines such as interleukins. (pp. 789-790) Helper T cells have the function of chemically or directly stimulating the proliferation of other T cells and B cells that have already bound antigen. Suppressor T cells function to moderate the normal immune response by suppressing the activity of T and B cells and releasing cytokines that suppress their activity. Cytotoxic T cells have the function of destroying cells in the body that have been invaded by viruses and cancer cells, and are involved in transplant rejection of foreign tissue. (pp. 791-792) Cytokines are soluble glycoproteins released by activated T cells. They increase the defense activity of T cells, B cells and macrophages. The specific cytokines and their role in the immune response are summarized in Table 21.4. Hypersensitivity is an antigen-induced condition that results in abnormally strong immune responses to a harmless antigen. Immediate hypersensitivities include anaphylactic shock and atopy. Subacute hypersensitivities include cytotoxic and immune complex hypersensitivities. All of this involves antibodies. Delayed sensitivities include allergic contact dermatitis and transplant rejection. These hypersensitivities affect T cells (pp. 797-799).

Copyright © 2010 Pearson Education, Inc.

257

258

Text and media Teacher's manual of human anatomy and physiology 30. Autoimmune diseases result from changes in the structure of self antigens, ineffective or inefficient programming of lymphocytes, and the cross-reaction of antibodies produced against foreign antigens with self antigens. (p. 799) 31. The decline in immune system performance with age probably reflects genetic aging. (p. 799)

Critical Thinking Problems and Clinical Application 1. a. Jenny has severe combined immunodeficiency disease (SCID) in which T cells and B cells fail to develop. At best, only a few lymphocytes can be detected. If left untreated, this condition is fatal. B. Jenny's brother has the closest antigenic match since the two children are from the same parents. C. A bone marrow transplant with cord blood stem cells is the next best chance of survival. It is hoped that by replacing the bone marrow stem cells, the T-cell and B-cell populations will approach normal. i.e. Epstein-Barr virus is the etiologic agent of infectious mononucleosis, usually a self-limited condition with recovery within a few weeks. Rarely, the virus causes the formation of cancerous B cells: Burkitt's lymphoma. Y. SCID is a birth defect that lacks the common stem cells that become T cells and B cells. AIDS is the result of an infection process by a virus that selectively inactivates CD4 (helper) T cells. Both result in severe immunodeficiency that exposes the individual to opportunistic pathogens and body cells that have lost (cancerous) control of their normal functions. (p. 796) 2. IgA is mainly found in mucus and other secretions that coat body surfaces. It plays an important role in preventing pathogens from entering the body. The lack of IgA would lead to frequent major and minor infections of the paranasal sinuses or respiratory tract. (p. 784) 3. The leakage of plasma proteins into the interstitial fluid causes an increase in osmotic pressure, resulting in increased plasma fluid leakage and localized edema. This swelling dilutes the pathogen and carries any foreign material into the lymphatics. The fluid flow also transports complement and clotting factors to the injury site. (pp. 770-771) 4. Costanza showed the typical signs of anaphylactic shock, an immediate hypersensitivity reaction. This typical inflammatory response (redness, edema, etc.) at the site of allergen exposure (the bite in this case) is triggered whenever tissue in the body is injured. You would benefit from a topical cream that contains an antihistamine. (p. 798) 5. The HIV virus is transmitted from mother to baby through the placenta. Caroline's helper T cells are infected. This is so devastating to the immune response because of the role of helper T cells in activating the humoral B cell immune response and activating cytotoxic T cells. Caroline takes medication to control the infection and slow the progression of her illness to AIDS. They take a combination of drugs from three categories: reverse transcriptase inhibitors, protease inhibitors and fusion inhibitors. (pp. 796 and 797)

Recommended Reading Brown, Phyllida. "Cinderella goes to the ball." Nature 410 (6832) (April 2001): 1018–1020.

Copyright © 2010 Pearson Education, Inc.

Chapter 21

The immune system: innate and adaptive body defenses

Casellas, Rafael and others. "Contribution of receptor editing to the antibody repertoire". Science 291 (5508) (February 2001): 1541–1544. Check it out Erika. "The Virtue of Tolerance". Nature 418 (6896) (July 2002): 364-366. Dove, Alan. "New Class of HIV Drugs Show Promise". Nature Medicine 7(12) (December 2001): 1265. DuClos, Terry K. "C-reactive protein and the immune response." Science and Medicine 8(2) (March/April 2002): 108–117. wow trisha "Innate Immunity: The Old System Gains New Respect". Science 291 (5511) (March 2002): 2068-2071. King, Leslie B, and John G Monroe. "B cell receptor rehabilitation: pause for thought". Science 291 (5508) (February 2001): 1503–1506. Kloetzel, Peter M. "Antigen Processing by the Proteasome." Nature Reviews: Molecular Cell Biology 2 (3) (March 2001): 179-193. Marano, Daniel A. "Ground Rescue". Psychology Today 41(5) (Sept/Oct 2008): 57-58. Marshall, Eliot. "Lupus: A Mysterious Disease Keeps Its Secrets Closely Guarded". Science 296 (5568) (April 2002): 689-691. McCune, Joseph N. "The Dynamics of CD4+ T Cell Depletion." Nature 410 (6831) (April 2001): 1002–1007. Medzhitov, Rusian, and Charles A. Janeway, Jr. "Decoding of Self and Non-Self Patterns by the Innate Immune System." Science 296 (5566) (April 2002): 298-300. Minkel, JR "Where's the AIDS Vaccine?" Scientific American: Special Issue 17(4) (December 2007): 72-75. Murphy, William J. "Natural killer cell alloreactivity in bone marrow transplantation." Science and Medicine 8(3) (May/June 2002): 162–171. Nabel, Gary J. "Challenges and Opportunities for AIDS Vaccine Development." Nature 410 (6831) (April 2001): 1002–1007. Piot, Peter and others. "The Global Impact of HIV/AIDS". Nature 410 (6831) (April 2001): 974–979. Ralph, Janet. "Activation of Autoimmune Attacks". Science News 173(16) (May 2008): 10. Rudd, Pauline M., et al. "Glycosylation and the immune system". Science 291 (5512) (March 2001): 2370-2376. Taniguchi, Tadatsugu, and Akinori Takaoka. "A Weak Signal for Strong Responses: Interferon-Alpha/Beta Revisited". Nature Reviews: Molecular Cell Biology 2 (5) (May 2001): 378-386. Tuma, Rabiya S. "How the Body Protects the Gut." Discover 29 (1) (January 2008): 58. Vinuesa, Carola G. and Christopher C. Goodnow. "DNA boosts immunity." Nature 416 (6881) (April 2002): 595-598. Vivier, Eric, and Christine A. Biron. "A pathogen receptor on natural killer cells". Science 296 (5571) (May 2002): 1248–1249.

Copyright © 2010 Pearson Education, Inc.

259

22

respiratory system

Goals

Gas exchange between blood, lungs and tissues

Functional Anatomy of the Respiratory System 1. Identify the organs that make up the airways in descending order until they reach the alveoli. 2. Describe the location, structure, and function of each of the following: nose, sinuses, pharynx, and larynx. 3. Name and describe different protective mechanisms of the respiratory system. 4. Distinguish between conductive and respiratory zone structures. 5. Describe the structure of the respiratory membrane and relate structure to function. 6. Describe the general structure of the lungs and pleurae. Respiratory Mechanics 7. Explain the functional significance of the partial vacuum that exists in the intrapleural space. 8. Relate Boyle's law to the events of inspiration and expiration. 9. Explain the relative roles of the respiratory muscles and lung elasticity in creating volume changes that cause air to flow in and out of the lungs. 10. List several physical factors that affect lung ventilation. 11. Explain and compare the different lung volumes and capacities. 12. Define the dead space. 13. List the types of information that can be obtained from lung function tests.

14. State Dalton's partial pressure law and Henry's law. 15. Describe how atmospheric and alveolar air differ in composition and explain these differences. 16. Associate Dalton's and Henry's laws with external and internal respiratory events. Transport of respiratory gases in the blood 17. Describe how oxygen is transported in the blood and explain how the loading and depletion of oxygen is affected by temperature, pH, BPG and PCO2. 18. Describe the transport of carbon dioxide in the blood. Control of breathing 19. Describe the neural control of breathing. 20. Compare and contrast the influences of arterial pH, arterial partial pressures of oxygen and carbon dioxide, pulmonary reflexes, volition, and emotions on respiratory rate and depth. Breathing adjustments 21. Compare and distinguish hyperventilation on exertion and hyperventilation. 22. Describe the process and effects of acclimatization to high altitude. Homeostatic Imbalance of the Respiratory System 23. Compare the causes and consequences of chronic bronchitis, emphysema, asthma, tuberculosis and lung cancer.

260 Copyright © 2010 Pearson Education, Inc.

Chapter 22 Developmental Aspects of the Respiratory System 24. Follow the embryonic development of the respiratory system.

respiratory system

25. Describe the normal changes that occur in the respiratory system from infancy through old age.

Suggested Lesson Plan I. Functional Anatomy of the Respiratory System (pp. 805-819; Figs. 22.1-22.11; Table 22.1) A. The Nose and Sinuses (pp. 806-809; Figs. 22.1-22.3) 1 The nose provides an airway to To breathe; humidifies, warms, filters and purifies the incoming air; provides an echo chamber for speech; and houses olfactory receptors. 2. The nose is divided into the external nose, which consists of hyaline cartilage and cranial bones, and the nasal cavity, which is entirely within the skull. 3. The nasal cavity consists of two types of epithelium: olfactory mucosa and respiratory mucosa. 4. The nasal cavity is surrounded by paranasal sinuses within the frontal, maxillary, sphenoid, and ethmoid bones, which serve to decompress the skull, warm and humidify air, and produce mucus. B. The pharynx (p. 809; Fig. 22.3) 1. The pharynx connects the nasal cavity and mouth above with the larynx and esophagus below. a. The nasopharynx serves only as an airway and contains the adenoids, which traps and destroys airborne pathogens. B. The oropharynx is a passageway for air and food that extends downward from the level of the soft palate to the epiglottis. C. The laryngopharynx is a passageway for air and food that lies just behind the epiglottis, extends into the larynx, and is continuous with the esophagus below. C. The Larynx (pp. 810-812; Figs. 22.3-22.5) 1. The larynx inserts at the top of the hyoid bone, opens into the laryngopharynx, and inserts into the lower part of the trachea. 2. The larynx provides an open airway, directs food and air into the appropriate passages, and produces sounds through the vocal cords. 3. The larynx consists of hyaline cartilages: thyroid, cricoid, paired arytenoids, cornea, and cuneiform; and the epiglottis, which is elastic cartilage. 4. The vocal cords form the core of the mucosal folds, the true vocal cords, which vibrate when air passes over them to produce sound. 5. The vocal cords and the medial space between them are called the glottis. 6. Voice production involves the intermittent release of exhaled air and the opening and closing of the glottis. 7. The Valsalva maneuver is a behavior in which the glottis closes to prevent exhalation and the abdominal muscles contract, resulting in an increase in intra-abdominal pressure. D. The trachea or trachea descends from the larynx through the neck to the mediastinum where it terminates in the primary bronchi (pp. 812-813; Fig. 22.6). Copyright © 2010 Pearson Education, Inc.

261

262

E. The bronchi and subdivisions (pp. 813–815; Figs. 22.7–22.9) 1. The conducting zone consists of the right and left primary bronchi entering each lung and emptying into the secondary bronchi . Bronchi supplying each lobe of the lungs. 2. The secondary bronchi branch into several orders of tertiary bronchi which eventually branch into bronchioles. 3. As the conducting airways become smaller, the supporting cartilage changes character until it is no longer present in the bronchioles. 4. The respiratory zone begins when the terminal bronchioles open into respiratory bronchioles, which end in alveolar ducts within alveolar sac groups composed of alveoli. a. The respiratory membrane consists of a single layer of squamous epithelium, type I cells, surrounded by a basal lamina.

F.

B. Cuboid type II cells are interspersed between the type I cells and secrete surfactant. C. Alveoli are surrounded by elastic fibers, contain open alveolar pores and alveolar macrophages. Lungs and Pleura (pp. 815-819; Figs. 22.10-22.11) 1. The lungs occupy the entire thoracic cavity except for the mediastinum; Each lung is suspended in its own pleural cavity and connected to the mediastinum by vascular and bronchial appendages called the root of the lung. 2. Each lobe contains several bronchopulmonary segments, each supplied by its own artery, vein, and tertiary bronchus. 3. Lung tissue consists mainly of air spaces, and the rest of the lung tissue, its stroma, consists mainly of elastic connective tissue. 4. There are two circuits that supply the lungs: the pulmonary meshwork carries systemic blood to the lungs for oxygenation, and the bronchial arteries supply systemic blood to the lung tissue. 5. The lungs are innervated by sympathetic and parasympathetic motor fibers that contract or dilate the airways and visceral sensory fibers. 6. The pleura forms a thin, double-layered serosa. a. The parietal pleura covers the chest wall, the upper surface of the diaphragm, and continues around the heart between the lungs. B. The visceral pleura covers the outer surface of the lungs and follows its contours and fissures.

II. Mechanics of respiration (p. 819-826; Fig. 22.12-22.16; Tab. 22.2-22.3) A. Pressure conditions in the thoracic cavity (p. 819-820; Fig. 22.12) 1. The intrapulmonary pressure is the pressure in the alveoli, which rises and falls during respiration, but always ends up equal to atmospheric pressure. 2. Intrapleural pressure is the pressure in the pleural cavity. It also rises and falls with breathing, but is always about 4 mm Hg less than the intrapulmonary pressure. B. Lung ventilation (pp. 820-822; Figs. 22.13-22.14) 1. Lung ventilation is a mechanical process in which gas is moved in and out of the lungs in response to volume changes in the thoracic cavity. a. Boyle's law states that the pressure of a gas varies inversely with its volume at constant temperature.

Copyright © 2010 Pearson Education, Inc.

Chapter 22

respiratory system

2. During silent inspiration, the diaphragm and intercostals contract, resulting in an increase in thoracic volume, causing intrapulmonary pressure to drop below atmospheric pressure and air to flow into the lungs. 3. During forced inspiration, the accessory muscles of the neck and thorax contract, increasing thoracic volume in addition to the increase in volume during silent inspiration. 4. Silent exhalation is a passive process that depends primarily on the elastic recoil of the lungs when the pectoral muscles relax. 5. Forced expiration is an active process that relies on the contraction of abdominal muscles to increase intra-abdominal pressure and squeeze the rib cage. C. Physical Factors Influencing Lung Ventilation (pp. 822-824; Fig. 22.15) 1. Airway resistance is the friction to which air is subjected in the airways; Gas flow is reduced as airway resistance increases. 2. Alveolar surface tension due to water in the alveoli brings the walls of the alveoli closer together, which is a force that must be overcome to expand the lungs. 3. Lung compliance is determined by compliance of the lung tissue and surrounding chest and alveolar surface tension. D. Tidal Volumes and Lung Function Tests (pp. 824-826; Fig. 22.16; Table 22.2) 1. Tidal volumes and certain combinations of volumes, called breathing capacities, are used to obtain information about a person's respiratory status. a. Tidal volume is the amount of air that moves in and out of the lungs with each breath during silent breathing. B. The inspiratory reserve volume is the amount of air that can be forcefully inspired in addition to the tidal volume. C. The expiratory reserve volume is the amount of air that can be evacuated from the lungs after tidal expiration. i.e. The residual volume is the amount of air that remains in the lungs after a maximum forced exhalation. Y. The inspiratory capacity is the sum of the tidal volume and the inspiratory reserve volume and represents the total amount of air that can be inspired after a tidal expiration. F. Functional residual capacity is the residual volume combined with the expiratory reserve volume and represents the amount of air remaining in the lungs after a tidal expiration. Grams. Vital capacity is the sum of tidal volume, inspiratory reserve, and expiratory reserve and is the total amount of exchangeable air. h The total lung capacity is the sum of all lung volumes. 2. Anatomical dead space is the volume of ducts in the conductive zone, which is a volume that never contributes to gas exchange in the lungs. 3. Pulmonary function tests assess loss of respiratory function using a spirometer to distinguish between obstructive and restrictive lung disease. E. Non-respiratory air movements (p. 826; Table 22.3) 1. Non-respiratory air movements cause movement of air into or out of the lungs but are unrelated to respiration (coughing, sneezing, crying, laughing), hiccups and yawning.

Copyright © 2010 Pearson Education, Inc.

263

264

Text and media guide to human anatomy and physiology

3. Gas exchange between blood, lungs and tissues (pp. 827-830; Figs. 22.17-22.19; Table 22.4) A. Gases have basic properties defined by Dalton's law of partial pressures and Henry's law (pp. 827–828; Table 22.4). 1. Dalton's law of partial pressures states that the total pressure exerted by a gas mixture is the sum of the pressures exerted by each gas in the mixture. 2. Henry's law states that when a gas mixture comes into contact with a liquid, each gas will dissolve in the liquid in proportion to its partial pressure. B. The composition of alveolar gas differs significantly from atmospheric gas due to the gas exchange that occurs in the lungs, the humidification of the air by the airways, and the mixing of alveolar gas that occurs with each breath (p. 828). C. External respiration: pulmonary gas exchange (pp. 828-830; Figs. 22.17-22.19) 1. External respiration involves the uptake of O2 and the release of CO2 from hemoglobin in red blood cells. a. There is a sharp partial pressure gradient between the blood in the pulmonary arteries and the alveoli, and O2 diffuses rapidly from the alveoli into the blood, but carbon dioxide moves in the opposite direction along a much less pronounced pressure gradient. B. The difference in the degree of partial pressure gradients of oxygen and carbon dioxide reflects the fact that carbon dioxide is much more soluble in blood than oxygen. C. The ventilation-perfusion coupling ensures a close correspondence between the amount of gas reaching the alveoli and the blood flow in the pulmonary capillaries. i.e. The respiratory membrane is usually very thin and has a large surface area for efficient gas exchange. D. Internal respiration (p. 830; Fig. 22.17) 1. The diffusion gradients of oxygen and carbon dioxide are inverse to those of external respiration and pulmonary gas exchange. 2. The partial pressure of oxygen in tissues is always lower than in blood, so oxygen readily diffuses into tissues, while carbon dioxide has a similar but less dramatic gradient in the opposite direction.

4. Transport of respiratory gases in the blood (pp. 830-834; Fig. 22.20-22.22) A. Oxygen transport (pp. 830-832; Fig. 22.20-22.21) 1. Since molecular oxygen is poorly soluble in the blood, only 1.5% is dissolved in the plasma, while the remaining 98.5% has to be transported in the hemoglobin. a. Up to four oxygen molecules can reversibly bind to a hemoglobin molecule: one oxygen to each iron. B. Hemoglobin's affinity for oxygen changes with each successive oxygen bound or released, making oxygen loading and unloading very efficient. 2. At higher plasma partial pressures of oxygen, little oxygen is given off by hemoglobin, but when the partial pressure of plasma falls dramatically, such as B. during intense physical exercise, much more oxygen can be delivered to the tissues. 3. Temperature, blood pH, PCO2 and the amount of BPG in the blood affect the hemoglobin saturation at a certain partial pressure.

Copyright © 2010 Pearson Education, Inc.

Chapter 22

respiratory system

B. Carbon Dioxide Transport (pp. 832-834; Fig. 22.22) 1. Carbon dioxide is transported in the blood by three routes: 7-10% dissolved in plasma, 20% transported in hemoglobin bound to globins and 70% transported as bicarbonate , an important buffer for blood pH. 2. The Haldane effect stimulates the CO2 exchange in the lungs and tissue: If the partial pressure of the plasma oxygen and the oxygen saturation of the hemoglobin decrease, more CO2 can be transported in the blood. 3. The blood's carbonic-bicarbonate buffering system is formed when CO2 combines with water and dissociates, creating carbonic and bicarbonate ions, which can release or absorb hydrogen ions.

V. Control of Respiration (pp. 834-839; Figs. 22.23-22.26) A. Neural Mechanisms (pp. 834-836; Fig. 22.23) 1. Two areas of the medulla oblongata are extremely important for respiration: the upper part of respiration the dorsal group near the root of cranial nerve IX and the ventral respiratory group extending from the spinal cord to the junction of the pons and medulla oblongata. 2. The ventral respiratory group is an integrating and rhythmic center containing separate groups of neurons, some firing during inspiration and others during expiration. a. Inspiratory neurons stimulate contraction of the diaphragm and intercostal muscles via the phrenic and intercostal nerves. B. When expiratory neurons fire, output to the respiratory muscles is interrupted, the muscles relax, and the lungs retract. 3. The cyclical behavior of the inspiratory and expiratory neurons produces a respiratory rate of 12 to 15 breaths per minute, called eupnea. 4. The pontine respiratory group within the pons modifies the respiratory rhythm and prevents hyperinflation of the lungs through an inhibitory effect on the medullary respiratory centers. 5. It is likely that mutual inhibition by different respiratory centers is responsible for the respiratory rhythm. B. Factors affecting respiratory rate and depth (pp. 836-839; Figs. 22.24-22.26) 1. The most important factors affecting respiratory rate and depth are the changing values ​​of CO2, O2 and H+ im arterial blood. a. The receptors that control fluctuations in these parameters are central chemoreceptors in the medulla oblongata and peripheral chemoreceptors in the aortic arch and carotid arteries. B. Elevations in arterial PCO2 cause increased levels of CO2 in the cerebrospinal fluid, leading to stimulation of central chemoreceptors and ultimately an increase in respiratory rate and depth. C. A significant drop in arterial PO2 is necessary to produce changes in respiratory rate and depth because of the large stores of O2 in hemoglobin. i.e. As H+ accumulates in plasma, respiratory rate and depth increases in an attempt to remove carbonic acid from the blood through the loss of CO2 from the lungs. 2. The higher brain centers change the rate and depth of breathing. a. The limbic system, strong emotions, and pain activate the hypothalamus, which alters the rate and depth of breathing.

Copyright © 2010 Pearson Education, Inc.

265

266

Text and Media Guide for Teachers of Human Anatomy and Physiology b. The cerebral cortex can voluntarily control breathing by bypassing the spinal centers and directly stimulating the respiratory muscles. 3. Lung irritation reflexes respond to inhaled irritants into the nasal passages or trachea by causing reflex bronchoconstriction in the airways. 4. Inflation or the Hering-Breuer reflex is activated by stretch receptors in the visceral pleura and conducting airways and protects the lungs from over-stretching by inhibiting inspiration.

SEEN. Breathing Adjustments (pp. 839-840) A. Exercise (p. 839) 1. During intense exercise, deeper, more vigorous breathing, called hyperventilation, ensures that tissue oxygen needs are being met. 2. Three neural factors contribute to the change in respiration: psychic stimuli, cortical stimulation of skeletal muscles and respiratory centers, and excitation impulses from respiratory areas of active muscles, tendons, and joints. B. Altitude (pp. 839-840) 1. Acute Mountain Sickness (AMS) can result from a rapid transition from sea level to altitudes greater than 8,000 feet. 2. Long-term change from sea level to high altitude leads to acclimatization of the body, including increased ventilation rate, lower than normal hemoglobin saturation, and increased production of erythropoietin.

VIII. Homeostatic Imbalance of the Respiratory System (pp. 840-842; Fig. 22.27) A. Chronic obstructive pulmonary disease (COPD) is seen in patients with a history of smoking and causes progressive dyspnea, frequent cough and respiratory infections, and respiratory failure. (pp. 840-841; Fig. 22.27). 1. Obstructive emphysema is characterized by permanently enlarged alveoli and deterioration of the alveolar walls. 2. Chronic bronchitis causes excess mucus production, inflammation and fibrosis of the lining of the lower airways. B. Asthma is characterized by coughing, shortness of breath, wheezing and chest tightness caused by active airway inflammation (p. 841). C. Tuberculosis (TB) is an infectious disease caused by the bacterium Mycobacterium tuberculosis and transmitted through coughing and inhalation (pp. 841-842). D. Lung Cancer (p. 842) 1. In both sexes, lung cancer is the most common type of malignancy and is strongly associated with smoking. 2. Squamous cell carcinoma arises in the bronchial epithelium and tends to form masses that deflate and bleed. 3. Adenocarcinoma arises in peripheral areas of the lungs as nodules that develop from bronchial glands and alveolar cells. 4. Small cell carcinoma contains lymphocyte-like cells that cluster in the mediastinum and metastasize rapidly.

VIII. Developmental Aspects of the Respiratory System (pp. 842-843, 846; Fig. 22.28) A. In the fourth week of development, the olfactory placodes are present and give rise to the olfactory pits that form the nasal cavities (p. 842; Fig. 22.28). Copyright © 2010 Pearson Education, Inc.

Chapter 22

respiratory system

B. The nasal cavity extends backward to join the foregut, creating a crest that becomes the pharyngeal mucosa. The mesoderm forms the walls of the airways and the stroma of the lungs (p. 842; Fig. 22.28). C. As a fetus, the lungs are filled with fluid and there are vascular shunts that direct blood away from the lungs; at birth the fluid is emptied and the increased plasma PCO2 stimulates the respiratory centers (p. 843). D. Respiratory rate is highest in neonates and gradually decreases through adulthood; in old age the respiratory rate increases again (p. 843). E. As we age, the chest wall stiffens, the lungs lose elasticity, and the amount of oxygen we can use during aerobic breathing decreases (p. 846). F. The number of mucous glands and blood flow in the nasal mucosa decrease with age, as does the ciliary action of the mucosa and the activity of macrophages (p. 846).

Cross-references For more information on the topics covered in Chapter 22, see the chapters listed below. 1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th 11th 12th 13th 14th 15th 16th

Chapter 1: Mediastinum Chapter 2: Acids and Bases Chapter 3: Diffusion Chapter 4: Hyaline and elastic cartilage; squamous, cuboidal and pseudostratified epithelium; serous and mucous glands Chapter 7: cranial bones Chapter 10: respiratory muscles Chapter 12: medulla and pons; Cortex Chapter 13: chemoreceptors; Proprioceptors Chapter 14: Sympathetic Effects Chapter 15: Eustachian Tube; Lysozyme Chapter 18: Large Vessels Chapter 19: Autoregulation of Blood Flow; pulmonary circulation Chapter 20: Tonsils Chapter 21: Inflammation; Macrophages Chapter 26: Blood acid-base balance Chapter 28: Role of acidosis in the initiation of fetal respiration

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 36: Anatomy of the Respiratory System Exercise 37: Physiology of the Respiratory System PhysioEx™ 8.0 Exercise 37B: Mechanics of the Respiratory System: Computer Simulation 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 36: Respiratory System Anatomy Exercise 37: Respiratory System Physiology PhysioEx™ 8.0 Exercise 37B: Respiratory System Mechanics: Computer Simulation

Copyright © 2010 Pearson Education, Inc.

267

268

Text and media guide to human anatomy and physiology

Teaching Tips 1. Emphasize the difference between ventilation and breathing. 2. The conducting airways of the head are generally the most confusing respiratory structures. Spend time with diagrams and photographs that reinforce the three-dimensional anatomy of upper airway structures. 3. State the characteristics of the epithelia lining the conducting airways and why these epithelia are the right choice for this particular area. This reinforces the types of epithelia and gradually develops an intuitive sense in students so that they can predict the epithelia of all parts of the body. 4. During a discussion about the trachea, ask students why the rings of cartilage are C-shaped and not continuous. 5. Be careful that the class does not confuse the respiratory membrane with membrane structures at the subcellular level (plasma membrane, etc.). 6. Remind students that the pulmonary vessels are exceptions to the rule that arteries oxygenate blood and veins deoxygenate it. Students should not confuse the bronchial artery (oxygenated blood) with the pulmonary artery (deoxygenated blood). 7. Emphasize the development and importance of a slightly negative intrapleural pressure for normal inspiration. 8. Emphasize elastic recoil as the main mechanism of normal expiration. 9. A thorough understanding of diffusion is necessary to understand the movement of respiratory gases at the level of body tissues and lungs. Refer the class to the section on diffusion in Chapter 3 in advance. 10. Mention that cellular respiration is not the same as internal or external respiration, but that cellular respiration involves pathways of glucose breakdown. 11. Point out that the carbon dioxide transport system (bicarbonate buffer) is the most important mechanism for maintaining blood pH. 12. Students often have the misconception that oxygen levels are the primary stimulant of respiration. Emphasize that carbon dioxide levels are the most important factor.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Provide stethoscopes so students can hear breath sounds in different areas of their partner's chest. For example, bronchial sounds are produced by air passing through the large airways (trachea and bronchi), while muffled breath sounds are heard in the smaller airways and alveoli. 3. Ask students to use portable spirometers to measure their tidal volume, specifically tidal volume and vital capacity. 4. Provide straws, water glasses and pH paper. Have the students blow on the water in the glasses with the straws. Since the exhaled air contains a significant amount of CO2, the water must become acidic. Have them measure the pH of the water at regular intervals to track the change in pH. 5. Provide measuring tapes so students can measure the circumference of the chest before and after inhalation. 6. Use a torso model, respiratory system model, and/or stuffed animal model to show the respiratory system and related organs. 7. Use two slides with water between them to demonstrate the cohesive action of serous fluid between the thoracic cavity wall and the lungs through the pleura and its parts. (Note: Because of this force, movement of the thoracic cavity causes movement of the lungs because the lungs cannot move away from the chest wall under normal conditions.) Copyright © 2010 Pearson Education, Inc. All rights reserved.

Chapter 22

respiratory system

8. Use an open dome with balloons inside to demonstrate the pressure changes as the diaphragm contracts and relaxes. (Note: The top of the dome should have a one-hole stopper with a glass Y-tube protruding into the jar; two small balls will be attached to the Y-tube; the bottom of the jar will be covered with a flexible elastic film.) 9. Use a stringed instrument to demonstrate the effect of vibration and thickness on sound production. 10. Add washing powder to a glass of water and dip a cloth in it to demonstrate the role of the surfactant in the lungs in reducing the surface tension of water and attracting other water molecules. 11. Use a freshly opened lemonade to demonstrate and explain Henry's Law. 12. Demonstrate the location of the paranasal sinuses with a complete or Beauchene skull. 13. Get fresh lamb or beef (lung plus trachea and heart) from a slaughterhouse. Insert a rubber hose firmly into the windpipe and connect the hose to a source of compressed air. Alternately inflate and passively deflate the lungs to illustrate the enormous air capacity and elasticity of the lungs. 14. Take some animal blood and blow air through the blood through a small section of the tube to demonstrate the color change that occurs when the blood is well oxygenated.

Critical Thinking/Discussion Points 1. Discuss why athletes would want to train at high altitude if their competition is at high altitude (relative to the Olympic training ground in US, Denver, Colorado) or even if their competition is at high altitude. . 2. Investigate changes in tidal volume in obstructive or congestive disorders. 3. Examine the relationship between oxygen debt and post-exercise muscle fatigue and increased respiratory rate. 4. Discuss the logic behind the structure of the conducting airways. Why are cartilage rings needed? Why is smooth muscle necessary in the walls of the conducting tubes? 5. Discuss the relationship between intrapulmonary pressure and intrapleural pressure. What happens to intrapulmonary pressure relative to intrapleural pressure when the Valsalva maneuver is performed? 6. Why are only slightly higher atmospheric carbon monoxide levels dangerous?

Library Research Topics 1. Research and list respiratory diseases caused by inhalation of toxic particles related to occupations like coal mining etc. 2. Examine cancer incidence in smokers versus non-smokers and in people working in respiratory risk areas versus people working in relatively safe breathing zones. 3. Review the current status of heart-lung transplants and why such a transplant is being considered. 4. Examine known and suspected causes of cot death. 5. Research the breathing problems that a premature baby may face. 6. Investigate the occurrence and frequency of respiratory diseases such as severe acute respiratory syndrome (SARS). 7. Describe the occurrence of tuberculosis and compare its treatment and treatment today to that in the 1930s. Copyright © 2010 Pearson Education, Inc.

269

270

Text and media guide to human anatomy and physiology

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all chapter-specific online media resources for Chapter 22 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 22.1 Functional Anatomy of the Respiratory System (pp. 805-819) Physiology® Interactive Systems Set of 10: Respiratory System: Anatomical Overview: Respiratory Structures Artist's Caption: The Upper Airway (Fig. 22.3c, p. 808) Item No . Caption: The Larynx (Figs. 22.4a-b, p. 810) Memory Game: The Respiratory System (Art) Memory Game: The Respiratory System (Cadaver) Section 22.2 Respiratory Mechanics (pp. 819-826) Physiology Interactive ® 10-Systems Suite: Lung Ventilation PhysioEx™ 8.0: Mechanics of the Respiratory System Section 22.3 Gas Exchange Between Blood, Lungs and Tissues (pp. 827-830) MP3 Tutor Session: Gas Exchange While Respiration Interactive Suite of 10 Systems Physiology®: Gas Exchange Section 22.4 Transport of respiratory gases in the blood (pp. 830-834) Set of 10 Physiology® Interactive Systems: Gas Transport Case Study: Pulmonary Embolism Section 22.5 Control of Respiration (pp. 834-839) Physiology® Interactive System Set: Control of Respiration Section 22.6 Respiration Adjustments (pp. 839-840) Section 22.7 Homeostatic imbalance of the respiratory system (pp. 840-842) Case study: Enfermed ad pulmonal Section 22.8 Aspects of development of the respiratory system (pp. 842-843, 846) Chapter summary Crossword 22.1 Kreu zword puzzles 22.2 Crossword puzzles 22.3 Crossword puzzles 22.4 Web links Chapter tests Art label test Consistency test Multiple choice test True-false test

Copyright © 2010 Pearson Education, Inc.

Chapter 22

respiratory system

Chapter practice test learning tools histology atlas myeBook flashcards glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Slides 1. Human lungs (CBS). Slides show bronchioles with pseudostratified ciliated epithelium.

Video 1. Breathing (FHS; 20 min, 1995). This video from the award-winning The New Living Body series shows a typical day in the life of a cystic fibrosis patient and the challenges faced by people with this inherited disease. 2. Circulation, respiration and respiration (FHS; 20 min, 2001). This program examines how oxygen and carbon dioxide are transported throughout the body, controlled by the brain as it responds to internal and external stimuli. 3. Human Respiratory System Videotape (BC; 25 min., 1998). This video provides an overview of the functions of the human respiratory system. 4. Respiration (FHS; 15 min, 1996). This video from the World of Living Organisms series describes external and internal respiration and how energy is generated for bodily functions. 5. Respiratory distress (ESF; 15 min). This program addresses the detection and emergency treatment of carbon monoxide poisoning, asthma emergencies, chronic obstructive pulmonary disease and hyperventilation. 6. Respiratory system: intake and exhaustion (FHS; 25 min, 1998). This program from The Human Body: Systems at Work series uses the analogy of a car's fuel intake and exhaust system to study the composition and functions of the respiratory system.

A.D.A.M.® Interactive Anatomy® 4.0 software (see full list on page 9 of this manual). A.D.A.M.® MediaPro (see page 9 of this manual for a complete list). A.D.A.M.® Anatomy Practice (see page 87 of this manual for a complete list). LOGAL® Biology Gateways™: Human Respiratory System CD-ROM (WNS; Win/Mac). Students can perform full simulated physiology experiments on the human respiratory system without expensive equipment. Students define variables; generate, collect and analyze data; formulate hypotheses; and develop models. 5. Interactive Set of 10 Physiology® Systems: Respiratory System (BC; Win/Mac). Interactive software that explores the physiology of the respiratory system. 1st 2nd 3rd 4th

Copyright © 2010 Pearson Education, Inc.

271

272

Human Anatomy and Physiology Instructor's Text and Media Guide 6. Practice Anatomy Lab™ 2.0: Human cadaver, anatomical models, histology, cat, fetal pig (see page 9 of this guide for a complete list). 7. PhysioEx™ 8.0: Mechanics of the Respiratory System: Computer Simulation 8. The Respiratory Tract (NIMCO; Win/Mac). Simulates the mechanical and physiological functioning of the human respiratory system. 9. Spirocomp™ Human Spirometry System (WNS; Windows). Includes a computerized spirometry system. It consists of hardware and software designed for quick and easy measurement of standard lung volumes. It can be used in a lab environment with students. 10. The Ultimate Human Body, version 2.2 (see page 9 of this manual for the full list).

Materials to Improve Teaching Thumbnails of all figures in Chapter 22 can be found in Appendix B.

Instructor Resource DVD/Overhead Slides Image Image Image Image Image Image Image Image Image

22,1 22,2 22,3 22,4 22,5 22,6 22,7 22,8 22,9 22,10 22,11 22,12 22,13

Figure 22.14 Figure Figure Figure Figure Figure Figure

22,15 22,16 22,17 22,18 22,19 22,20 22,21

figure figure figure figure

22,22 22,23 22,24 22,25

Figure 22.26

The main respiratory organs in relation to the surrounding structures. The Outer Nose. The upper respiratory tract. the larynx movements of the vocal cords. Tissue composition of the tracheal wall. driving zone passes. Structures of the breathing zone. Alveoli and respiratory membrane. Anatomical relationships of the organs of the thoracic cavity. A cast of the bronchial tree. Intrapulmonary and intrapleural pressure conditions. Changes in thoracic volume and sequence of events during inspiration and expiration. Changes in intrapulmonary and intrapleural pressure during inspiration and expiration. airway resistance. volumes and breathing capacities. Partial pressure gradients that promote the movement of gases in the body. Oxygen supply to the blood in the pulmonary capillaries at rest. Ventilation-perfusion coupling. Oxygen-hemoglobin dissociation curve. Influence of temperature, PCO2 and blood pH on the oxygen-hemoglobin dissociation curve. Transport and exchange of CO2 and O2. Location of the respiratory centers and their postulated connections. Neural and chemical influences on the respiratory centers of the brainstem. Negative feedback mechanism by which changes in PCO2 and blood pH regulate respiration. Location and innervation of peripheral chemoreceptors in the carotid and aortic bodies.

Copyright © 2010 Pearson Education, Inc.

Chapter 22 Figure 22.27 Figure 22.28 Table 22.1 Table 22.2 Table 22.3 Table 22.4 Connections

respiratory system

The pathogenesis of COPD. Embryonic development of the respiratory system. Major organs of the respiratory system Effects of respiratory rate and depth on alveolar ventilation of three hypothetical patients Non-respiratory movements of air (gas) Comparison of gas partial pressures and approximate percentages in the atmosphere and alveoli Homeostatic interrelationships between the respiratory system and other body systems

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 17. The airway from the external nostrils to an alveolus and the organs involved are as follows: Structures in the conduction zone: external nostrils, nasal cavity, pharynx (nasopharynx, oropharynx, laryngopharynx), larynx, trachea and left primary, secondary , tertiary bronchi and successive orders of bronchi, bronchioles and terminal bronchioles; Structures of the respiratory zone: respiratory bronchioles, alveolar ducts, alveolar sacs and alveoli. (pp. 805-816) 18. a. The trachea is reinforced with rings of cartilage to prevent tracheal collapse and keep the airway open despite pressure changes that occur during breathing. (p. 813) b. The benefit of the rings not being complete at the back is that it allows the esophagus to expand forward when swallowing. (p. 813) 19. The larynx of the adult male is larger overall and the vocal cords are longer than in females or children. These changes occur during puberty under the influence of increased testosterone levels. (p. 813) 20. a. Stretch tissue is essential for both normal inhalation and exhalation; Expiration depends almost entirely on the elastic recoil of the lungs when the inspiratory muscles are relaxed. (p. 819) b. Passages are air ducts used for heating, humidifying, and transporting air. (p. 813) 21. The volume of gas flow to and from the alveoli is directly proportional to the pressure difference between the outer atmosphere and the alveoli. Very small pressure differences are enough to create a large flow of gas. As intrapulmonary pressure decreases as chest volume increases, air rushes into the lungs to equalize the pressure. As the lungs retract, intrapulmonary pressure increases and gases leave the lungs. (p. 820) 22. Lung ventilation is affected by airway resistance, where gas flow is equal to pressure gradient divided by resistance. Gas flow varies inversely with resistance. Lung compliance is assessed by measuring the increase in lung volume that results from an increase in intrapulmonary pressure. The greater the increase in volume for a given increase in pressure, the greater the compliance. The ability of lung tissue to expand and retract, called lung elasticity, is essential for normal lung compliance. Surfactant lowers the surface tension of the alveolar fluid, so less energy is required to overcome the surface tension forces and expand the lungs. (pp. 822 and 823)

Copyright © 2010 Pearson Education, Inc.

273

274

Text and Media Teacher's Manual of Human Anatomy and Physiology 23. a. Minute ventilation is the total amount of gas that enters and leaves the airways in one minute. The alveolar ventilation rate accounts for the amount of air wasted in dead space areas and provides a measure of the concentration of fresh gases in the alveoli at any given time. (p. 825) b. Alveolar ventilation frequency provides a more accurate measure of respiratory efficiency because it only considers the volume of air actually participating in gas exchange. (p. 826) 24. Dalton's law of partial pressure states that the total pressure exerted by a gas mixture is the sum of the pressure exerted independently by each gas in the mixture. Henry's law states that when a gas mixture comes into contact with a liquid, each gas in the liquid will dissolve in proportion to its partial pressure and its solubility in the liquid. (p. 827) 25. a. Hyperventilation is deep breathing that rapidly releases carbon dioxide from the blood. B. When you hyperventilate, you expel more carbon dioxide. C. Hyperventilation increases blood pH. (p. 836) 26. Age-related changes include a loss of elasticity in the lungs and a stiffer chest wall. These factors lead to a slowly decreasing ventilation capacity of the lungs. These changes are accompanied by a decrease in the level of oxygen in the blood and reduced sensitivity to the stimulating effects of carbon dioxide. (p. 843)

Critical Thinking Questions and Clinical Applications 1. Under normal conditions, hemoglobin in arterial blood is almost completely (98%) saturated with oxygen. Therefore, hyperventilation increases oxygen saturation very little or not at all. However, hyperventilation will expel CO2 from the blood, terminating respiratory drive and possibly causing (1) cerebral ischemia due to hypocapnia and (2) O2 dropping to dangerously low levels, resulting in fainting. (p. 831) 2. a. The lung penetrated by the scalpel collapsed because the intrapleural pressure equaled atmospheric pressure, which allowed the pleural membranes to separate. B. Only the penetrated lung has collapsed because it is isolated from the remaining mediastinal structures (and from the other lung) by the pleural membranes. (p. 820) 3. Adjacent bronchopulmonary segments are separated from each other by partitions of dense connective tissue that are not traversed by major vessels. Therefore, it is possible for a surgeon to prepare adjacent segments. The only vessels that required cautery were the few major vessels of each bronchopulmonary segment. (p. 815) 4. Mary Ann suffers from decompression sickness caused by the rapid ascent in the airplane. During the dive week, he accumulated nitrogen gas in his tissues, which at normal altitude slowly and unnoticed exits his tissues. During the flight, however, the cabin pressure dropped fast enough to allow residual nitrogen gas to escape more quickly, leading to the symptoms. Returning to a lower altitude with higher air pressure upon landing will relieve your symptoms. (pp. 827 and 828)

Suggested reading Beall, Cynthia M., et al. "Lung nitric oxide in mountain dwellers". Nature 414 (November 2001): 411–412. Christensen, Damaris. "The ongoing problem of cystic fibrosis". Science News 161(4) (January 2002): 59-60. Copyright © 2010 Pearson Education, Inc.

Chapter 22

respiratory system

Fernández, Antonio B., R.H. Karas, A.A. Alsheikh-Ali, and P.D. Thompson. "Statins and Interstitial Lung Disease: A Systematic Review of the Literature and FDA Adverse Event Reports". TABLE 134 (4) (October 2008): pp. 824–830. Floyd, Katherine and others. "Resources needed for global tuberculosis response". Science 295 (5562) (March 2002): 2040–2046. Gosen, Reinoud, et al. Alabama. "Caveolae and Caveolines in the Respiratory System". Current Molecular Medicine 8(8) (December 2008): pp. 741-753. Kawabata, Y., et al. Alabama. "Smoking-related changes in fundic lung specimens resected for lung cancer: a semi-quantitative study correlated with postoperative course". Histopathology 53(6) (December 2008): pp. 707-714. Lipson, Stuart A. "Nitric Oxide and Respiration." Nature 413 (6852) (2001 Sep): 118-121. Mermigkis, C., et. Alabama. "Sleep quality and associated day sequences in patients with idiopathic pulmonary fibrosis". Medical Principles and Practices 18(1) (January 2009): pp. 10–15. Okada, Yasumasa, Z Chen, and S Kuwana. "Cytoarchitecture of central chemoreceptors in the mammalian ventral medulla". Physiology of Respiration 129 (December 2001): 13–23. O'Toole, George A. "A Resistive Switch." Nature 416 (6882) (April 2002): 695–696. Russel, David G. "Mycobacterium Tuberculosis: Here Today and Here Tomorrow." Nature Reviews: Molecular Biology 2 (8) (2001 August): 569-577. Vogel, Gretchen. "The absence of the gene takes the mice's breath away." Science 295 (5553) (2002 Jan): 253. Wiemann, Martin and D. Bingmann. "Ventrolateral neurons from medullary organotypic cultures: regulation of intracellular pH and bioelectrical activity". Physiology of Respiration 129 (December 2001): 57–70.

Copyright © 2010 Pearson Education, Inc.

275

23

The digestive system

11. Explain the dental formula and clearly distinguish between temporary and permanent teeth.

Objectives PART 1: THE DIGESTIVE SYSTEM AT A GLANCE 1. Describe the function of the digestive system and distinguish the organs of the digestive tract from the accessory digestive organs. Digestive Processes 2. Name and define the main processes that take place during the activity of the digestive system. Basic Functional Concepts 3. Describe stimuli and controls of digestive activity. Organs of the digestive system: relationships 4. Describe the location and function of the peritoneum. 5. Define retroperitoneal and name the retroperitoneal organs. 6. Define the splanchnic circulation. 7. Give the meaning of the hepatic portal system. 8. Describe the tissue composition and general function of each of the four layers of the digestive tract. PART 2: FUNCTIONAL ANATOMY OF THE DIGESTIVE SYSTEM The mouth and associated organs 9. Describe the gross and microscopic anatomy and basic functions of the mouth, pharynx and esophagus. 10. Describe the composition and functions of saliva and explain how the flow of saliva is regulated.

Digestive processes: from the mouth to the esophagus 12. Describe the mechanisms of chewing and swallowing. The Stomach 13. Identify the structural changes in the stomach wall that improve the digestive process. 14. Name the types of cells responsible for the secretion of the various components of the gastric juice and indicate the importance of each component for the activity of the stomach. 15. Describe the structure of the stomach and point out the changes in the basic structure of the digestive tract that aid in its digestive function. 16. Explain how gastric secretion and gastric motility are regulated. 17. Define and consider the alkaline tide. The Small Intestine and Associated Structures 18. Identify and describe the structural changes in the wall of the small intestine that improve the digestive process. 19. Distinguish the functions of the different cell types of the intestinal mucosa. 20. Describe the role of paracrine and local gut hormones. 21. Describe the histological anatomy of the liver. 22. Describe the role of bile in digestion and how its entry into the small intestine is regulated. 23. Describe the role of the gallbladder. 24. Describe the role of pancreatic juice in digestion.

276 Copyright © 2010 Pearson Education, Inc.

Chapter 23

The digestive system

25. Describe how the entry of pancreatic juice into the small intestine is regulated.

29. Name the end products of digestion of proteins, fats, carbohydrates and nucleic acids.

the colon

Absorption

26. Name the main functions of the large intestine. 27. Describe the regulation of bowel movements.

30. Describe the process of absorption of the breakdown products of food in the small intestine.

PART 3: PHYSIOLOGY OF DIGESTIVE AND CHEMICAL ABSORPTION

Developmental aspects of the digestive system

chemical digestion

31. Describe the embryonic development of the digestive system. 32. Describe the abnormalities of the gastrointestinal tract at different stages of life.

28. Name the enzymes involved in chemical digestion; Name the foods they affect.

Suggested Course of Instruction PART 1: OVERVIEW OF THE DIGESTIVE SYSTEM (pp. 851-858; Figs. 23.1-23.6) A. The organs of the digestive system are divided into two major groups: the alimentary canal and the accessory organs (p. 852). -853; Figure 23.1). 1. The alimentary canal or gastrointestinal (GI) tract is the continuous muscular digestive tract that runs throughout the body to digest and absorb food; Its organs include: mouth, throat, esophagus, stomach, small intestine and large intestine. 2. Additional digestive organs physically aid in digestion and produce secretions that break down food in the gastrointestinal tract; The organs involved are the teeth, tongue, gallbladder, salivary glands, liver and pancreas.

I. Digestive Processes (pp. 853 and 854; Figs. 23.2 and 23.3) A. Ingestion is the simple act of putting food in the mouth (p. 853). B. Propulsion moves food through the gastrointestinal tract and includes both swallowing and peristalsis (p. 853; Fig. 23.3). C. Mechanical digestion is the physical process of preparing food for chemical digestion and includes chewing, mixing, churning, and segmenting (pp. 853-854). D Chemical digestion is a series of catabolic steps in which enzymes break down complex food molecules into their chemical building blocks (p. 854). E. Absorption is the passage of digested end products from the lumen of the GI tract through mucosal cells into the blood or lymph (p. 854). F. Defecation removes indigestible substances from the body through the anus as feces (p. 854).

II. BASIC FUNCTIONAL CONCEPTS (p. 854; Fig. 23.4) A. The digestive system creates an ideal internal environment for its function in the lumen of the gastrointestinal tract, an area technically external to the body (p. 854; Fig. 23.4) . 1. Digestive activities in the gastrointestinal tract are triggered by mechanical and chemical stimuli.

Copyright © 2010 Pearson Education, Inc.

277

278

Text and Media Teacher's Manual of Human Anatomy and Physiology 2. Control of digestive activity is extrinsic and intrinsic (nervous and hormonal).

3. Organs of the Digestive System: Relationships (pp. 854-858; Figs. 23.5-23.6) A. Relation of the digestive organs to the peritoneum (pp. 854-856; Fig. 23.5) 1. The visceral peritoneum covers the outer surfaces of most digestive organs , and the parietal peritoneum lines the body wall of the abdominal-pelvic cavity. 2. The abdominal cavity lies between the visceral and parietal peritoneum and is filled with serous fluid. 3. The mesentery is a double layer of peritoneum that extends from the body wall to the digestive organs. It allows blood vessels, lymphatics, and nerves to reach the digestive organs, holds the organs in place, and stores fat. 4. The retroperitoneal organs lie behind the mesentery and lie against the dorsal abdominal wall. B. The splanchnic circulation serves the digestive system and includes the arteries which branch from the abdominal aorta to serve the digestive organs and the hepatic portal circulation (p. 856). C. Histology of the alimentary canal (pp. 856-857; Fig. 23.6) 1. The mucosa is the innermost moist epithelial membrane lining the entire alimentary tract. Secretes mucus, digestive enzymes and hormones; absorbs digestive end products into the blood; and protects against infectious diseases. 2. The submucosa is a layer of moderately dense connective tissue containing blood and lymphatic vessels, lymphatic follicles, and nerve fibers. 3. The external muscles are usually smooth muscle and are responsible for peristalsis and segmentation. 4. The serosa, the protective outer layer of the intraperitoneal organs, is the visceral peritoneum. D. The gastrointestinal tract has its own innervation consisting of enteric neurons that communicate widely to regulate digestive activity (pp. 857-858).

PART 2: FUNCTIONAL ANATOMY OF THE DIGESTIVE SYSTEM (pp. 858-895; Figs. 23.7-23.31; Boxes 23.1-23.3) IV. The mouth and associated organs (pp. 858-864; Figs. 23.7-23.11) A. The mouth is a mucosa-lined stratified squamous epithelium cavity surrounded by the lips, cheeks, palate, and tongue (pp. 858–864; Figs. 23.7–23.11). 1. The lips and cheeks have a skeletal muscle core covered on the outside by skin that helps hold food between our teeth when we chew and plays a small role in speaking. 2. The palate forms the roof of the mouth and consists of two parts: the hard palate at the front and the soft palate at the back. 3. The tongue is composed of interlocking bundles of skeletal muscle and is used to change the position of food during chewing, to mix food with saliva, to initiate swallowing, and to help form consonants for speech. 4. The salivary glands produce saliva that cleans the mouth, dissolves chemicals in food to add flavor, moistens food, and contains chemicals that initiate the breakdown of starch. 5. Teeth tear and grind food, breaking it into smaller pieces.

Copyright © 2010 Pearson Education, Inc.

Chapter 23

The digestive system

V. Pharynx (p. 864) A. The pharynx (oropharynx and laryngopharynx) provides a common passageway for food, fluid, and air (p. 864).

SEEN. The Esophagus (pp. 864-866; Fig. 23.12) A. The esophagus serves as a pathway for food and fluid from the laryngopharynx to the stomach, where it opens into the ventricle of the heart (pp. 864-866; Fig. 23.12).

VIII. Digestive Processes: Mouth to Esophagus (p. 866; Fig. 23.13) A. Chewing initiates the mechanical breakdown of food and mixes it with saliva (p. 866). B. Swallowing or swallowing is a complicated process involving two main phases (p. 866; Fig. 23.13). 1. The buccal phase is voluntary and takes place in the mouth where the bolus of food is pushed into the oropharynx. 2. The pharyngeal-esophageal phase is involuntary and occurs when food enters the esophagus through the pharynx.

VIII. The Stomach (pp. 866-877; Figs. 23.14-23.20; Boxes 23.1-23.2) A. The stomach is an intermediate storage facility where the chemical breakdown of protein begins and food is converted into chyme (pp. 866 to 869, Fig. 23.14). 1. The adult stomach is 15-25 cm in length; its diameter and volume vary according to the amount of food it contains. a. The major regions of the stomach include the cardiac region, fundus, corpus, and pyloric region. B. The convex lateral surface of the stomach is its major curvature and its convex medial surface is its minor curvature. C. Extending from the crooks are the minor and major omenta, which help connect the stomach to other digestive organs and the body wall. B. Microscopic anatomy (pp. 869-871; Figs. 23.15-23.16; Box 23.1) 1. The surface epithelium of the gastric mucosa is a simple columnar epithelium of goblet cells forming a protective bilayer of alkaline mucus. . 2. The gastric glands in the stomach produce gastric juice, which can be a combination of mucus, hydrochloric acid, intrinsic factor, pepsinogen, and various hormones. C. Digestive Processes Occurring in the Stomach (pp. 871-877; Figs. 23.17-23.20; Box 23.2) 1. Gastric secretion is controlled by nervous and hormonal mechanisms and occurs in three distinct phases: the head phase, the gastric and intestinal phase . 2. Reflex-mediated gastric muscle relaxation and visceral smooth muscle plasticity allow the stomach to absorb food and maintain internal pressure. 3. The interstitial cells of Cajal establish the basic electrical rhythm of the stomach's peristaltic waves. 4. The rate of gastric emptying is determined by the contents of the stomach and how it is processed in the small intestine.

Copyright © 2010 Pearson Education, Inc.

279

280

Text and media guide to human anatomy and physiology

IX. Small Intestine and Associated Structures (pp. 877-890; Figs. 23.21-23.28; Box 23.3) A. The small intestine is the site where nutrient digestion and absorption is completed (pp. 877-880; Figs. 23.21-23.23) . 1. It extends from the pyloric sphincter to the ileocecal valve, where it opens into the large intestine. It has three divisions: the duodenum, the jejunum, and the ileum. 2. It is highly suitable for absorption with three microscopic modifications: circular plicas, villi, and microvilli. 3. The intestinal crypts or Lieberkühn crypts secrete intestinal juice, which serves as a carrier fluid for the absorption of nutrients from the chyme. B. The liver and gallbladder are subsidiary organs of the small intestine (pp. 880-885; Figs. 23.24-23.25). 1. The liver is the largest gland in the body and has four lobes. 2. The liver consists of liver lobes, which are made up of sheets of liver cells (hepatocytes). 3. The liver's digestive function is to produce bile, which is an emulsifier of fats. 4. Bile is a yellow-green alkaline solution containing bile salts, bile pigments (mainly bilirubin), cholesterol, neutral fats, phospholipids and a variety of electrolytes. 5. The gallbladder stores and concentrates bile that is not immediately needed for digestion. 6. Bile does not normally enter the small intestine until the gallbladder contracts when stimulated by cholecystokinin. C. The pancreas is a retroperitoneal accessory gland (pp. 885-886; Figs. 23.26-23.28). 1. Pancreatic juice is mostly water and contains enzymes that break down all categories of food and electrolytes. 2. The secretion of pancreatic juice is regulated by local hormones and the parasympathetic nervous system. D. Digestive Processes Occurring in the Small Intestine (pp. 887-890; Table 23.3) 1. Food takes 3 to 6 hours to complete its digestive journey through the small intestine, the site of virtually all nutrient absorption. 2. Most of the substances necessary for chemical digestion in the small intestine are imported from the pancreas and liver. 3. Optimal digestive activity in the small intestine depends on a slow and measured supply of chyme from the stomach. 4. Segmentation is the most common movement of the small intestine.

X. The Large Intestine (pp. 890-895; Figs. 23.29-23.31) A. The large intestine absorbs water from indigestible remains of food and excretes it as feces (pp. 890-895; Figs. 23.29-23.30). 1. The large intestine has three unique features: teniae coli, haustra, and omental appendages and has the following subdivisions: cecum, appendage, colon, rectum, and anal canal. 2. The lining of the colon is thick and has crypts with many mucus-producing goblet cells. 3. Bacteria that enter the large intestine through the small intestine and anus colonize the large intestine and ferment some of the indigestible carbohydrates. Copyright © 2010 Pearson Education, Inc.

Chapter 23

The digestive system

B. Digestive Processes in the Large Intestine (pp. 893-895; Fig. 23.31) 1. Movements observed in the large intestine include haustral contractions and mass movements. 2. Forced defecation into the rectum by mass movement stretches the rectal wall and triggers the defecation reflex.

PART 3: PHYSIOLOGY OF DIGESTIVE AND CHEMICAL ABSORPTION (pp. 895–905; Figs. 23.32–23.34) XI. Chemical Digestion (pp. 895-897; Figs. 23.32-23.34) A. Chemical digestion is a catabolic process in which large food molecules are broken down into chemical components (monomers) small enough to be absorbed by the body's lining of the alimentary canal (pp. 895-897; Figs. 23.32-23.34). 1. Chemical digestion is performed by enzymes secreted by the intrinsic and accessory glands of the digestive tract and used in hydrolysis reactions. 2. Carbohydrates a. Monosaccharides are simple sugars that are easily absorbed (glucose, galactose and fructose). B. Disaccharides consist of two monosaccharides (maltose, lactose and sucrose) joined together. C. The digestible polysaccharide found in food is starch; other polysaccharides such as cellulose cannot be broken down by humans. i.e. The chemical digestion of carbohydrates begins in the mouth, where salivary amylase breaks down large polysaccharides into smaller fragments. 3. Proteins that are digested into amino acids in the gastrointestinal tract include not only dietary proteins but also enzymatic proteins that are secreted into the lumen of the gastrointestinal tract. a. Pepsin, secreted by chief cells, initiates chemical digestion of proteins in the stomach. B. Renin is produced in babies and breaks down milk proteins. C. Pancreatic enzymes such as trypsin and chymotrypsin further break down proteins in the small intestine. i.e. The brush border enzymes carboxypeptidase, aminopeptidase and dipeptidase cause the release of individual amino acids in the small intestine. 4. The small intestine is the only place for fat digestion. a. Lipases are secreted by the pancreas and are the enzymes that digest fat after it has been pretreated with bile. 5. Pancreatic nucleases, present in pancreatic juice, hydrolyze nucleic acids (both DNA and RNA) into their nucleotide monomers.

XII. Absorption (pp. 898-901; Fig. 23.34) A. Absorption occurs throughout the small intestine and is mostly complete before the chyme reaches the ileum (pp. 898-901; Fig. 23.34). 1. Intake of Specific Nutrients a. Glucose and galactose are transported to the epithelial cells by common protein transporters and then enter the capillary blood by facilitated diffusion. B. Several types of transporters transport the different amino acids before they reach the capillary blood by diffusion. C. Monoglycerides and free fatty acids from lipid digestion combine with bile salts and lecithin to form micelles necessary for lipid absorption. Copyright © 2010 Pearson Education, Inc.

281

282

Human anatomy and physiology Text and media guide for course instructors d. Pentose sugars, nitrogenous bases and phosphate ions are actively transported through the epithelium by special transporters in the villous epithelium. Y. The small intestine absorbs vitamins from food, while the large intestine absorbs vitamins B and K. f. Electrolytes are actively absorbed throughout the small intestine, with the exception of calcium and iron, which are absorbed in the duodenum. grams. Water is the most abundant substance in chyme and is 95% absorbed in the small intestine by osmosis. 2. Nutrient malabsorption can be caused by anything that interferes with the release of bile or pancreatic juices, as well as factors that damage the intestinal lining.

XIII. Aspects of development of the digestive system (pp. 901, 904–905; Fig. 23.35) A. Embryonic development (pp. 901, 904; Fig. 23.35) 1. The epithelial lining of the developing digestive tract is formed from endoderm with the rest of the Wall arises from the mesoderm. 2. The foremost endoderm touches the recessed area of ​​the superficial ectoderm where the membranes fuse to form the oral membrane and eventually the mouth. 3. The end of the hindgut fuses with an ectodermal cavity, the proctodeum, to form the cloacal membrane and eventually the anus. 4. By the eighth week, the digestive tract is a continuous tube that stretches from the mouth to the anus. B. Aging (pp. 904-905) 1. The motility of the gastrointestinal tract decreases, the production of digestive juices decreases, absorption is less efficient, and peristalsis decreases, resulting in less frequent bowel movements and frequent constipation. 2. Diverticulosis, fecal incontinence and gastrointestinal cancer are very common problems in the elderly.

Cross-references For more information on the topics covered in Chapter 23, see the chapters listed below. 1. Chapter 1: Serous membranes 2. Chapter 2: Enzymatic function; Acids and bases; Carbohydrates, Lipids, Proteins and Nucleic Acids 3. Chapter 3: Microvilli; membrane transport 4. Chapter 4: Simple columnar epithelium; areolar connective tissue; Serous and Mucous Glands 5. Chapter 9: Smooth Muscles 6. Chapter 10: Chewing and Movement of the Tongue 7. Chapter 12: Brainstem Centers 8. Chapter 13: Receptors; reflex activity; Nervous Plexus 9. Chapter 14: Sympathetic and Parasympathetic Controls 10. Chapter 15: Papillae and Taste Buds 11. Chapter 16: Hormones

Copyright © 2010 Pearson Education, Inc.

Chapter 23

The digestive system

12. 13. 14. 15.

Chapter 17: Pernicious Anemia Chapter 20: Lymphatic Tissue; Dairy products; tonsils Chapter 21: Macrophages Chapter 24: Liver metabolism and detoxification; role of chylomicrons in lipid metabolism; gall formation; Transport of cholesterol and blood lipids 16. Chapter 26: Electrolyte balance

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 38: Anatomy of the Digestive System Exercise 39: Chemical and Physical Processes of Digestion PhysioEx™ 8.0: Exercise 39B: Chemical and Physical Processes of Digestion: Computer Simulation 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 38: Anatomy of the Digestive System Exercise 39: Chemical and Physical Processes of Digestion PhysioEx™ 8.0: Exercise 39B: Chemical and Physical Processes of Digestion: Computer Simulation

Teaching Tips 1. Emphasize that the digestive system is not just the digestive tract (gastrointestinal tract), but all of the organs and tissues that help in the digestive process. 2. Point out that the gastrointestinal tract consists of the same four basic layers throughout its length, but that each area is modified for its specific task. 3. Digestion is the process of breaking down large particles into smaller particles. Emphasize that the general function of the digestive system is the mechanical and chemical breakdown of ingested substances, followed by the absorption of those substances and the excretion of indigestible materials. 4. Most students have trouble with the serous lining of the abdominal viscera. Use diagrams and photographs of real tissue to support descriptions of the relatively complex folded nature of these membranes. 5. Spend some time on the hepatic portal system. This is another example of blood entering one capillary bed, being directed into a vein and then another capillary bed before returning to the general circulation. 6. When discussing tract histology, ask the class, “What is the logical choice of epithelium for the mouth? For the esophagus? Emphasize that the choice of columnar epithelium for the mucosal layer of the gastrointestinal tract is optimal for its function. 7. Emphasize that the esophagus is not covered by serosa but has an adventitia as the outer lining. 8. Emphasize that the lower (gastroesophageal) sphincter is not a true sphincter. 9. As an interesting point, mention that heartburn is actually acid reflux into the esophagus. 10. Point out the change in the muscularis externa in the stomach in relation to the function of the stomach. Copyright © 2010 Pearson Education, Inc.

283

284

Text and Media Human Anatomy and Physiology - Teacher's Guide 11. Ask the students to note the difference between the relatively thin surface structure of the lining of the stomach and the small intestine. Ask students why this is happening. 12. Intrinsic factor is a gastric secretion necessary for the absorption of vitamin B12; However, the actual absorption of this vitamin does not occur in the stomach, but much later in the ileum. 13. When each cell of the gastric mucosa is described, assign the logical function of each type to the general function of the stomach. 14. Mention that the three areas of the small intestine are distinguished histologically by examining the structure of the mucosa. 15. Use black line graphs or matrices to demonstrate the three structural modifications in the small intestine that greatly increase the surface area for absorption. 16. Introduce the digestive function of the small intestine and introduce the topic by asking the class, "What functions must occur when chyme enters the early part of the small intestine?" Using carefully directed questions, the class must answer: neutralizing acids, further digesting carbohydrates and proteins, and initiating lipid digestion. 17. Students have difficulty with flow paths in the lobe of the liver. Use two-dimensional cross sections of a lobe and indicate the directions of blood flow and bile flow. Emphasize the difference between the hepatic portal vein and the hepatic vein. 18. Ask the class why the hepatic artery is needed since the liver is already supplied by the portal vein. You should be able to answer that portal blood is "spent" blood from the digestive tract. 19. Emphasize that the pancreas is a dual function/structure gland, endocrine and exocrine. 20. Teniae coli is best explained using a cross-sectional diagram followed by a longitudinal section. 21. Emphasize that the time the contents of the colon are in contact with the mucosa determines the water content in the stool. Too little residence time in the colon means watery stool, too long constipation. 22. Point out the logical names of digestive enzymes: the prefix usually indicates the substrate and the suffix “-ase” means enzyme. An exception, trypsin, was mentioned prior to the general acceptance of the "-ase" convention. 23. Spend time digesting and absorbing fats, from emulsification to moving through the bloodstream. Point out that carbohydrates and proteins take a different (vascular) route to the liver than lipids.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Ask students to calculate their total calorie intake over a 24 hour period using a simple calorie calculator available at any drug store. Ask students to review their diet carefully to see what improvements could (and should) be made in their eating habits. 3. Demonstrate the emulsifying action of bile: First, mix oil and water and allow the layers to separate. Then add the bile salts and shake vigorously. Point out that the oil layer was broken up into hundreds of tiny globules of fat by the action of bile salts. 4. Use a torso model and/or stuffed animal model to show the digestive organs. 5. Use gallstones obtained from a surgeon to view them during analysis of the liver and gallbladder.

Copyright © 2010 Pearson Education, Inc.

Chapter 23

The digestive system

6. Use a long, not fully inflated balloon to demonstrate peristalsis. 7. Use a human skull or tooth models to demonstrate the different shapes, types and numbers of teeth. 8. Demonstrate molecular models of carbohydrates, fats and proteins.

Critical thinking/topics for discussion 1st 2nd 3rd 4th 5th 6th 7th 8th 9th

Discuss the symptoms, treatment, and prognosis of a hiatal hernia. Explain why it is important to chew food well. Discover the importance of the liver. Discuss the cause, treatment, and prevention of ulcers. Discuss why it is necessary for someone with ulcer symptoms to see a doctor instead of just using antacids. Discuss the reasons older adults should be screened for colon cancer. Investigation of the reasons for the treatment and prognosis of a colostomy. If you eat a high-salt meal, why not lose a large amount of water in your feces? Discuss how people on low-carb diets have relatively constant glucose levels.

Library Research Topics 1. Study the causes and treatment of ulcers. 2. Study the benefits of fiber. 3. Study liver transplantation in terms of reasons for transplantation, procedure and prognosis. 4. Research the latest causes and treatments for hepatitis. What are the consequences of inflammation/infection of the liver? 5. What are malabsorption syndromes? Its causes? your treatments? 6. Examine the different types of dysmotility associated with the digestive tract. Include possible secondary complications and suggested treatments. 7. What are the most common digestive tract cancers? Are Cancers Limited to the Gastrointestinal Tract? Are they limited to accessory structures?

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all of the chapter-specific online media resources for Chapter 23 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives PART 1: DIGESTIVE SYSTEM OVERVIEW (pp. 851-858) Physiology® Interactive System Set of 10: Digestive System: Orientation Art Labeling: Alimentary Canal and Associated Organs (Fig. 23.1, p. 852)

Copyright © 2010 Pearson Education, Inc.

285

286

Text and media guide to human anatomy and physiology Section 23.1 Digestive processes (pp. 853–854) Section 23.2 Basic functional concepts (pp. 854) Section 23.3 Organs of the digestive system: relationships (pp. 854–858) PART 2: FUNCTIONAL ANATOMY OF THE DIGESTIVE SYSTEM (pp. 858-895) Interactive Physiology® 10 System Set: Digestive System: Anatomy Overview Interactive Physiology® 10 System Set: Digestive System Control Interactive Physiology® 10 System Set: Digestive System: Motility Interactive Physiology® 10 System Suite: Digestive System: Secretion Memory Game: Structures of the Digestive System Memory Game: The Digestive System Section 23.4 The Mouth and Associated Organs (pp. 858-864) Section 23.5 The Throat (p. 864) Section 23.6 An Esophagus (pp. 864-866) Section 23.7 Digestive Processes: From the Mouth to the Esophagus (p. 866) Section 23.8 The Stomach (pp. 866–877) Artist's Caption: Walking anatomy of the stoma (Fig. 23.14 , p. 868) Artist's caption: a microscopic atom of the stomach (Fig. 2 3.15a–b, p. 869) Section 23.9 The small intestine and associated structures (pp. 877–890) Section 23.10 The large intestine (pp. 890–895 ) Artist's caption: gross anatomy of the colon (Fig. 23.29a, p. 891) Case Study: Iron Deficiency Anemia PART 3: PHYSIOLOGY OF CHEMICAL DIGESTIVE AND ABSORPTION (pp. 895-905) MP3 Session Tutor: Digestion and Absorption Interactive Physiology® 10 System Suite: Digestion and Absorption Section 23.11 Section Chemical Digestion (pp. 895-897) 23.12 Absorption (pp. 898-901) Section 23.13 Developmental Aspects of the Digestive System (pp. 901, 904-905) Chapter Summary Histolo gy Atlas myeBook Flashcard Glossary

Copyright © 2010 Pearson Education, Inc.

Chapter 23

The digestive system

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Slides 1. Digestive System Set (CBS). Contains tissue samples from all major organs of the digestive tract. 2. Set of human digestive organs and glands (CBS). It represents all organs and glands of the digestive tract.

Video 1. Breakdown (FHS; 28 mins, 1984). From the award-winning The Living Body series, this video explores the digestive effects of eating a meal by following the food through the entire alimentary canal. 2. Digestion (FHS; 20 min, 1995). This video from the award-winning The New Living Body series provides an introduction to the structures and functions of the digestive tract. 3. The digestive system: down the hatch! (IM; 20 min, 2001). From the four part series Amazing Adventures Inside the Human Body. This video examines the mechanical and chemical processes of digestion that convert food into nutrients and vitamins that the body can absorb. 4. Digestive System: Your Personal Powerhouse (FHS; 34 mins, 1998). This program from The Human Body: Systems at Work series explores the processes by which the digestive system acts as a source of energy for the body, converting food into energy. 5. The Human Body: Digestive System (IM; 30 min., 2002). This DVD provides an overview of the components of the digestive system including teeth, esophagus, stomach, pylorus, liver, pancreas, duodenum, jejunum, ileum, sigmoid process and rectum. It also explains actions such as ingestion, chewing, digestion and excretion. 6. Human digestive system (IM; 19 min, 2008). This DVD shows how the human body digests fats, carbohydrates and proteins. Describes tests for fat, starch, sugar, and protein; examines the structures of the digestive system; identifies the foods affected by the major digestive enzymes and bile salts; and studies the effect of pH on enzymes. 7. Understanding the Digestive System (NIMCO). Explain the digestive system with 3D animation and insights from Dr. David Gerstman. Describe the salivary glands, tongue and absorption in the intestinal villi. It also includes a discussion of the structures and functions of the liver, gallbladder, pancreas, and gastrointestinal tract. 8. Human digestive system videotape (BC; 33 min., 1998). This video gives an overview of the human digestive system.

Software 1. A.D.A.M.® Interactive Anatomy® 4.0 (see full list on page 9 of this manual). 2. A.D.A.M.® MediaPro (see page 9 of this manual for a complete list). 3. A.D.A.M.® Anatomy Practice (see page 87 of this manual for a complete list).

Copyright © 2010 Pearson Education, Inc.

287

288

Human Anatomy and Physiology Instructor's Text and Media Guide 4. Physiology® 10-System Interactive Set: Digestive System (BC; Win/Mac). This module guides students through animations that clearly and simply explain each part of the human digestive process, from basic anatomy to complete digestion and absorption. Students learn at their own pace, pausing and/or playing animations as needed, and test their knowledge with worksheets and quizzes available at the end of the module. 5. Practice Anatomy Lab™ 2.0: Human cadaver, anatomical models, histology, cat, fetal pig (see full list on page 9 of this manual). 6. PhysioEx™ 8.0: Chemical and physical processes of digestion: computer simulation. 7. The Ultimate Human Body, version 2.2 (see page 9 for the full list).

For material to improve the lesson Thumbnails of all illustrations in Chapter 23, see Appendix B.

Index Instructor Slide/Resource DVD Image Image Image Image

23,1 23,2 23,3 23,4

Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure

23,5 23,6 23,7 23,8 23,9 23,10 23,11 23,12 23,13 23,14 23,15 23,16

Figure Figure Figure Figure Figure

23,17 23,18 23,19 23,20 23,21 23,22

Figure Figure Figure Figure Figure

23,23 23,24 23,25 23,26 23,27 23,28

Alimentary canal and related accessory digestive organs. Activities of the gastrointestinal tract. peristalsis and segmentation. Neural reflex pathways triggered by stimuli inside or outside the gastrointestinal tract. The peritoneum and the abdominal cavity. Basic structure of the digestive tract. Anatomy of the oral cavity (mouth). Dorsal surface of the tongue and tonsils. salivary glands. human teeth. Longitudinal section of a canine in its bony socket. Microscopic structure of the esophagus. Swallow (swallow). Anatomy of the Stomach. Microscopic anatomy of the stomach. Photographs of a stomach ulcer and the bacteria that most commonly cause it. Neural and hormonal mechanisms that regulate the release of gastric juice. HCl secretion mechanism by parietal cells. Peristaltic waves in the stomach. Neural and hormonal factors that inhibit gastric emptying. The small intestine duodenum and related organs. Structural changes in the small intestine that increase its surface area for digestion and absorption. Villi and microvilli of the small intestine. Gross anatomy of the human liver. Microscopic anatomy of the liver. Structure of the enzyme-producing tissue of the pancreas. Activation of pancreatic proteases in the small intestine. Mechanisms promoting the secretion and release of bile and pancreatic juice. Copyright © 2010 Pearson Education, Inc.

Chapter 23 Figure 23.29 Figure 23.30 Figure 23.31 Figure 23.32 Figure 23.33 Figure 23.34 Figure 23.35 Table 23.1 Table 23.2 Table 23.3 Make connections

The digestive system

Gross anatomy of the colon. Mesenteries of the abdominal digestive organs. defecation reflex. Flowchart of the digestion and chemical absorption of food. Digestion and absorption of proteins in the small intestine. Emulsification, digestion and absorption of fats. Embryonic development of the digestive system. Hormones and paracrine products affecting digestion General description of the functions of the gastrointestinal organs Control of small intestinal motility Homeostatic interrelationships between the digestive system and other body systems

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 18. On page 852, Fig. 23.1. 19. The digestive system contains local nerve plexuses known as the local (enteric) nervous system or gut brain. This consists essentially of nerve plexuses in the wall of the alimentary canal that extend the entire length of the gastrointestinal tract. These plexuses react to local stimuli in the gastrointestinal tract by triggering short and long reflexes. The intestinal brain mediates only short reflexes. Long reflexes are triggered by external and local stimuli and involve both the gut brain and the ANS. (Sympathetic nerves inhibit the activity of the gastrointestinal tract, while parasympathetic nerves, mainly the vagus nerve, stimulate it.) (pp. 857-858) 20. The basic structure of the alimentary tract wall consists of four layers: mucosal, submucosa, muscular and serosa . The mucosa consists of a superficial epithelium, under which lies a small amount of connective tissue called the lamina propria and a sparse amount of smooth muscle fibers, the muscularis mucosae. The mucosal epithelium is usually a simple columnar epithelium rich in mucus-secreting goblet cells and other types of glands. The mucus protects certain digestive organs from being digested by the enzymes working in their cavities and facilitates the passage of food along the tract. In some digestive organs, the mucosa contains both enzyme-secreting cells and hormone-secreting cells. The lamina propria, which consists of connective tissue from the areoles and contains lymph nodes, is important for defense against bacteria and other pathogens. In the small intestine, the muscularis mucosae sheds the mucosa in a series of small folds that greatly increase its surface area for secretion and absorption. The submucosa is an areolar connective tissue containing blood vessels, lymphatic vessels, nerve endings, and epithelial glands. Its vascular network supplies the surrounding tissue and transports the absorbed nutrients. Its nerve plexus is part of the enteric innervation of the gastrointestinal tract. The muscularis externa mixes and propels food through the digestive tract. This muscle layer usually has an inner circular layer and an outer longitudinal layer of smooth muscle cells, although variations on this pattern exist.

Copyright © 2010 Pearson Education, Inc.

289

290

Text and media guide to human anatomy and physiology

21

22. 23.

24

25

The serosa consists of areolar connective tissue covered by mesothelium, a single layer of squamous epithelial cells. It is the outermost protective layer and the peritoneum. (pp. 856-857) The mesentery is a double peritoneal fold that separates the small intestine from the posterior abdominal wall. The mesocolon is a specialized dorsal mesentery that connects the transverse colon to the parietal peritoneum of the posterior abdominal wall. The great omentum is also a double peritoneal membrane that covers the gyri of the small intestine and surrounds the transverse part of the colon. (pp. 855, 890, 868) The six functional activities of the digestive system are intake, propulsion, mechanical digestion, chemical digestion, absorption, and defecation. (pp. 853 and 854) a. The boundaries of the oral cavity include the lips, cheeks, tongue, palate and oropharynx. B. The epithelium is stratified squamous because the walls must withstand considerable abrasion. (p. 858) The normal number of permanent teeth is 32; Deciduous teeth, 20. b. The enamel covers the crown; Cement, Root C. Dentin makes up most of the tooth. i.e. The pulp is located in the central cavity of the tooth. Soft tissue structures (connective tissue, blood vessels and nerve fibers) form the pulp. (pp. 862 and 863) The two phases of swallowing are as follows: a. Oral (voluntary) swallowing phase: Organs involved: tongue, soft palate; Activities: The tongue compacts the feed into a ruminant, pushing the ruminant into the oropharynx by contractions of the tongue. The soft palate is lifted to close the upper nasopharynx. (p. 866)

B. Pharyngeal-esophageal phase (involuntary): Organs involved: pharynx and esophagus; Activities: Motor impulses sent from the swallowing center to the muscles, which contract to move food up the esophagus by peristalsis. The arrival of the peristaltic/alimentary wave at the gastroesophageal sphincter causes it to open. (p. 866) 26. Parietal cells secrete hydrochloric acid and intrinsic factor. Chief cells produce pepsinogen. The mucus cells in the neck produce mucus that helps protect the stomach lining from damage caused by gastric juices. Enteroendocrine cells secrete hormones into the lamina propria. (p. 870) 27. Gastric secretion is controlled by neural and hormonal mechanisms. Gastric secretion stimulation involves three distinct phases: the head, gastric, and intestinal phases. The head phase occurs before food enters the stomach and is triggered by the sight, smell, taste, or thought of food. The input is relayed to the hypothalamus, which stimulates the vagus nuclei in the medulla oblongata, causing motor impulses to be sent through vagus nerve fibers to the stomach. This reflex can be weakened by depression or loss of appetite. The gastric phase is initiated by neural and hormonal mechanisms once food reaches the stomach. The expansion of the stomach activates stretch receptors and triggers reflexes that transmit impulses to the medulla and then back to the stomach, resulting in the release of acetylcholine. Acetylcholine stimulates the outflow of gastric juice. In this phase, the hormone gastrin is more important for gastric juice secretion than neural influences. Chemical stimuli provided by food directly activate gastrin-secreting cells. Gastrin stimulates the gastric glands to secrete more gastric juices. Gastrin secretion is inhibited by high acidity. The intestinal phase begins when partially digested food begins to fill the duodenum. This filler stimulates the cells in the lining of the gut to release a hormone Copyright © 2010 Pearson Education, Inc.

Chapter 23

28

29

30

31

32.

33. 34.

The digestive system

(intestinal gastrin), which stimulates the gastric glands to briefly resume their secretory activity; However, when more food enters the small intestine, the enterogastric reflex is triggered, which inhibits gastric secretion and the entry of food into the duodenum to prevent small intestine congestion. In addition, intestinal hormones (enterogastrones) inhibit stomach activity. (p. 872 and 873) a. The common hepatic and cystic ducts merge to form the bile duct, which merges with the pancreatic ducts just before entering the duodenum. (p. 881) b. The merging point of the common bile duct and pancreatic duct is called the hepatopancreatic ampulla. (p. 877) The absence of bile (which causes the emulsification of fats) and/or pancreatic juice (which essentially contains the only major source of lipase) causes fat absorption to be so slow that most of the fat can pass through. to the colon. (pp. 899-900) Kupffer cells work to remove debris, such as bacteria, from the blood. Hepatocytes produce bile in addition to their many metabolic activities. (p. 881) Brush border enzymes are intestinal digestive enzymes; these are part of the plasma membrane of the microvilli of intestinal absorption cells. (p. 878) b. Chylomicrons are fat droplets composed of triglycerides combined with small amounts of phospholipids, cholesterol and free fatty acids and coated with protein. They are formed in the receiving cells and reach the milk cells. (p. 900) Activation of pancreatic enzymes in the small intestine illustrates the body's wisdom that this activation process protects the pancreas from being digested by its own enzymes. (p. 886) Common inflammatory diseases include appendicitis in adolescents, ulcers and gallbladder problems in middle-aged adults, and constipation in old age. (p. 904) Effects of aging on digestive system activity include reduced motility, reduced production of digestive juices, less efficient absorption, and slowing of peristalsis. (p. 904)

Critical Thinking Issues and Clinical Application 1. If the agent promotes increased intestinal motility without increasing volume, there is a possibility of diverticulosis because the stiffness of the colon contractions increases when the volume of waste is small. This increases pressure on the colon wall, which encourages the formation of diverticula. If the product irritates the intestinal mucosa, diarrhea occurs. Intestinal contents move quickly through the small and large intestines, not allowing enough time for water absorption, which can lead to dehydration and electrolyte imbalance. (pp. 893-895) 2. This patient has the classic symptoms of a gallbladder attack in which a gallstone has lodged in the cystic duct. The pain is discontinuous and colicky as it reflects the rhythm of the peristaltic contractions (tense-relax-tense-relax, etc.). The stone can be removed surgically or by sonic or laser treatment. If it is not removed, bile will backflow into the liver and jaundice will result. (p. 885) 3. The baby's blood would indicate acidosis because intestinal juice flows through the colon and has little or no time for the reabsorption of water and substances such as bicarbonate ions dissolved in the water by the colon. (p. 895) 4. a. Most stomach ulcers are caused by Helicobacter pylori infection. This drug regimen successfully eradicates the infection. B. The possible consequences of failure to treat could be surgical removal of the existing ulcer due to internal bleeding or the development of multiple ulcers. (pp. 870 and 871)

Copyright © 2010 Pearson Education, Inc.

291

292

Text and Media Human Anatomy and Physiology Instructor's Manual 5. An endoscope is an instrument used to visually examine any body cavity and consists of a fiber optic tube illuminated with a lens. Polyps observed were promptly removed, as most colorectal carcinomas arise from initially benign polyps. Colon cancer is now the second leading cause of cancer death in men in the US (p. 908) 6. Along with the risk of dehydration, severe diarrhea can lead to potassium depletion, which can lead to an electrolyte imbalance that affects your neuromuscular system. Function. Her severe weakness could be a symptom of this. (p. 895) 7. The ring of tonsils around the pharynx is protective because the tonsils serve to invite pathogens in and expose the body's defense system to them so that a person can develop immunity. What better place for such a function than right at the opening of the food, liquid and air passage? (p. 760)

Suggested Reading Bansil, R., KR Bhaskar, J.D. Bradley, P. Garik, J.T. LaMont, HE Stanley, and BS Turner. "Viscous fingering of HCl through gastric mucus". Nature 360 ​​(December 1992): 458. Barary, Nathan, and Leonard I. Zon. "Endothel: chicken soup for the endoderm". Science 294 (5542) (2001 Oct): 530-531. Blaser, M. "The Bacteria Behind Ulcers." Scientific American 274 (February 1996): 104-107. Benendia, M. and P. Tiollais. "Hepatitis B Virus". Scientific American 264 (April 1991): 116. Boroom, Ken. "Get to the bottom of the irritable bowel." New Scientist 198 (2651) (April 2008): 13. Desai, KM, W.C. Sessa and J.R. Shovel. "Involvement of nitric oxide in the reflex relaxation of the stomach for the absorption of food or liquid". Nature 351 (June 1991): 477. Fackelmann, KA "Trapping a gene for colorectal cancer." Science News 144 (December 1993): 388. Ferber, Dan. "Strategy for warping insect cells in cracked gut". Science 294 (5550) (December 2001): 2269. Greenaugh, W.B. and N. Hirschhorn. "Advances in Oral Rehydration Therapy". Scientific American 264 (May 1991): 50. Harder, Ben. "Germs that are good for the body." Science News 161(5) (February 2002): 72-74. Koff, R. "Solving the Mysteries of Viral Hepatitis." Scientific American: Science & Medicine 1 (March/April 1994): 24-33. Lambolez, Florencia and Benedita Rocha. "A Molecular Gut Response". Science 294 (5548) (November 2001): 1848–1849. Levine, DS "Barrett's Esophagus". Scientific American: Science & Medicine 1 (November/December 1995): 16-25. Raloff, J. "Household Cells Can Become Killers." Science News 143 (May 1993): 277. Richardson, S. "Tongue Bugs." Discover (1995 Oct): 44-46. Turner, CG "Teeth and Prehistory in Asia." Scientific American 260 (February 1989): 88-96. Schiller, L.R. "Peristalis". Scientific American: Science & Medicine 1 (Nov/Dec 1995): 38-47. Seppa, N. "In food allergies, immune cells crowd into the gut." Science News 159(14) (April 2001): 214. Uvnas-Moberg, K. "The growing and reproductive gastrointestinal tract." Scientific American 261 (July 1989): 78–83.

Copyright © 2010 Pearson Education, Inc.

Nutrition, metabolism and regulation of body temperature

24

16. Explain the difference between substrate level phosphorylation and oxidative phosphorylation.

Goals Diet and Nutrition 1. Define nutrient, essential nutrient and calories. 2. Name the six main categories of nutrients. Think about the important sources and the main uses of the cell phone. 3. Distinguish between simple and complex carbohydrate sources. 4. List the main uses of carbohydrates in the body. 5. Indicate the use of fats in the body. 6. Distinguish between saturated, unsaturated and trans fat sources. 7. Distinguish between nutritionally complete and incomplete proteins. 8. Indicate the use of proteins in the body. 9. Define nitrogen balance and indicate possible causes for positive and negative nitrogen balance. 10. Distinguish between fat-soluble and water-soluble vitamins and list the vitamins in each group. 11. For each vitamin, list important sources, functions in the body, and important consequences of its deficiency or excess. 12. List the essential minerals for health; List important food sources and describe how they are used. Overview of metabolic reactions 13. Define metabolism. Explain how catabolism and anabolism differ. 14. Define oxidation and reduction and give the importance of these reactions in metabolism. 15. Name the role of coenzymes used in cellular oxidation reactions.

Metabolism of Important Nutrients 17 Outline the important events and products of glycolysis, the Krebs cycle and electron transport. 18. Define glycogenesis, glycogenolysis and gluconeogenesis. 19. Describe the process by which fatty acids are oxidized into energy. 20. Define ketone bodies and give the stimulus for their formation. 21. Describe how amino acids are metabolized for energy. 22. Describe the need for protein synthesis in the body cells. Metabolic states of the body 23. Explain the concept of pools of amino acids or carbohydrates and fats and describe how substances in these pools can be interconverted. 24. List important events of the absorption and post-absorption states and explain how these events are regulated. The metabolic function of the liver 25. Describe different metabolic functions of the liver. 26. Distinguish between LDL and HDL in terms of their main structures and functions in the body. Energy balance 27. Explain what is meant by energy balance of the body.

293 Copyright © 2010 Pearson Education, Inc.

294

Text and Media Human Anatomy and Physiology Teacher Guide 28. Describe some theories of the regulation of food intake. 29. Define Basal Metabolic Rate and Total Metabolic Rate. Name the influencing factors in each case. 30. Distinguish between body core temperature and shell temperature. 31. Describe how body temperature is regulated and identify the common mechanisms that regulate heat production/storage and heat loss from the body.

Developmental aspects of nutrition and metabolism 32. Describe the effects of inadequate protein intake on the fetal nervous system. 33. Describe the cause and consequences of the age-typical low metabolism. 34. Describe the ways in which medications commonly taken by older people can affect their diet and health.

Suggested Lesson Plan I. Diet and Nutrition (pp. 911-918; Figs. 24.1-24.2; Tables 24.1-24.3) A. A nutrient is used by the body to promote normal growth and development. Those categorized as major nutrients are carbohydrates, lipids, and proteins; Vitamins and minerals are micronutrients (p. 911; Fig. 24.1). 1. A healthy diet consists of foods from each of the five food groups: grains; Fruits and vegetables; meat, beans and fish; Dairy products; and oils The basic nutritional principles for a healthy diet are to eat less, avoid junk food and exercise more. B. Carbohydrates consist of sugars (monosaccharides and disaccharides) from fruits, sugar cane, beets, honey and milk; and polysaccharides from cereals, fruits and vegetables (p. 912; Table 24.1). 1. Glucose is used by the organism as fuel for the reactions that synthesize ATP, which is required by neurons and red blood cells. C. The most abundant dietary lipids are triglycerides, or neutral fats, and can be saturated (obtained from animal sources, coconut oils, and hydrogenated fats (trans fats)) or unsaturated (derived from plant sources) (pp. 912-913; Table 24.1). ). 1. The essential fatty acids linoleic acid and linolenic acid cannot be manufactured by the body and must therefore be obtained from food. 2. Cholesterol is found in egg yolks, meat, offal, shellfish and milk, but about 85% of the body's cholesterol is produced by the liver. 3. Lipids help the body absorb fat-soluble vitamins, serve as cellular fuel, are an integral part of myelin sheaths and cell membranes, form adipose tissue, and act as regulatory molecules. D. Proteins, which contain all of the essential amino acids, are complete proteins and are found in eggs, milk, fish, and meat; Proteins lacking or low in one or more of the essential amino acids are incomplete and are found in legumes, nuts, and grains (pp. 914-915; Fig. 24.2; Table 24.1). 1. Proteins are important structural and functional molecules in the body. 2. Amino acids from proteins can be used to synthesize new molecules or burned for energy. 3. Healthy rates of protein synthesis require a homeostatically regulated nitrogen balance, which compares the rate of new protein incorporation into tissues with the rate of protein breakdown to meet energy needs. E. Vitamins are micronutrients that act primarily as coenzymes, many of which are not produced by the body and must be consumed (pp. 915-916; Table 24.2). Copyright © 2010 Pearson Education, Inc.

Chapter 24

F.

Nutrition, metabolism and regulation of body temperature

1. Vitamins A, D, E and K are fat-soluble and are absorbed when bound to ingested lipids. 2. Water-soluble vitamins such as vitamin B and vitamin C are absorbed along with water in the gastrointestinal tract. Minerals are used by the body to work in concert with other molecules, they can be incorporated into tissues to increase their resistance, or they can be ionized in body fluids or bound to organic compounds (pp. 917-918; Table 24.3). 1. The body needs moderate amounts of seven minerals: calcium, phosphorus, potassium, sulfur, sodium, chlorine and magnesium.

II. Overview of Metabolic Reactions (pp. 918-922; Figs. 24.3-24.5) A. Metabolic processes are either anabolic, in which larger molecules are synthesized from smaller molecules, or catabolic, in which smaller molecules are synthesized and large molecules are broken down into smaller molecules . (pp. 918-920; Figure 24.3). B. Oxidation-reduction reactions are coupled reactions in which electrons are transferred from one molecule to another, resulting in an energy transfer between molecules (pp. 920-921). 1. In the body, oxidation-reduction reactions are enzyme-catalyzed reactions that require specific coenzymes that transfer the energy contained in dietary fuels to other molecules, ultimately leading to the synthesis of ATP from ADP. C. ATP synthesis can occur via two mechanisms: substrate-level phosphorylation, in which high-energy phosphate groups are directly transferred from phosphorylated substrates to ADP, or oxidative phosphorylation, in which energy from food fuels is used to create a proton gradient. which is used to bind phosphates to ADP (pp. 921-922; Fig. 24.4-24.5).

3. Main nutrient metabolism (pp. 922 to 934; Figs. 24.6 to 24.16; Table 24.4) A. Carbohydrate metabolism (pp. 922 to 930; Figs. 24.6 to 24.13; Table 24.4) 1. Glucose enters the cell by facilitated diffusion and is phosphorylated to glucose-6-phosphate, essentially locking glucose in the cell. 2. Glucose enters glycolysis, an anaerobic process that takes place in the cytosol. a. In phase 1 of glycolysis, glucose is phosphorylated to fructose-6-phosphate in a series of steps to provide the activation energy for events that occur later in the pathway. B. In phase 2 of glycolysis, fructose-6-phosphate is split into two three-carbon fragments: glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. C. In phase 3 of glycolysis, the pair of three-carbon fragments produced in phase 2 are oxidized to transfer hydrogen to NAD+ and the oxidized fragments are phosphorylated. i.e. The end products of this series of reactions are two molecules of pyruvic acid, two molecules of NADH, and four molecules of ATP, although two ATP were consumed early in the process. 3. The two pyruvic acid molecules can take two different routes depending on the availability of oxygen. a. If there is enough oxygen in the cell, glycolysis continues and NADH donates its electrons to the electron transport chain. B. When sufficient oxygen is not available, NADH returns its hydrogen to pyruvic acid, forming lactic acid, which allows NAD+ to continue functioning as an electron acceptor.

Copyright © 2010 Pearson Education, Inc.

295

296

Text and media manual for instructors in human anatomy and physiology c. Once enough oxygen is available in the cell, lactic acid is oxidized back to pyruvic acid and enters the aerobic pathways. 4. Pyruvic acid is transported by aerobic pathways to the mitochondria where it enters the Krebs cycle. a. Pyruvic acid is first converted to acetyl-CoA by removing a carbon, oxidizing the acetic acid residue, and adding coenzyme A. b. Acetyl-CoA enters the Krebs cycle, where it goes through eight sequential steps that produce a series of keto acids that eventually result in the production of oxaloacetic acid. C. The net yield of the Krebs cycle is four CO2 molecules, six NADH molecules, two FADH2 molecules, and two ATP molecules per pair of acetyl-CoA molecules made from glucose. 5. The electron transport chain is the process of aerobic respiration that requires oxygen and involves the scavenging of hydrogen extracted from food fuels during oxidation by O2, resulting in the formation of water, a process called oxidative phosphorylation. a. In the electron transport chain, the hydrogens of NADH and FADH2 are transported by a series of coenzymes, resulting in the transport of H+ from the mitochondrial matrix to the intermembrane space. B. H+ diffuses back into the mitochondrial membrane via an enzyme, ATP synthase, which phosphorylates ADP to ATP as H+ diffuses. 6. Because the cell cannot store large amounts of ATP, other processes are used to handle glucose beyond what can be used in the ATP synthetic pathways. a. Glycogenesis is a process that creates glycogen from glucose when high levels of cellular ATP begin to inhibit glycolysis. B. Glycogenolysis is a process that breaks down glycogen into glucose when blood sugar levels begin to fall. C. Gluconeogenesis is a process that forms glucose from non-glycosylated molecules to sustain blood sugar when food sources and glucose stores are depleted. B. Lipid metabolism (pp. 930-932; Figs. 24.14-24.15; Table 24.4) 1. Lipids are the most concentrated source of energy in the body and produce about twice as much energy as carbohydrates or proteins. 2. Triglyceride breakdown involves the cleavage of the molecule into glycerol and fatty acids: the glycerol portion is converted into glyceraldehyde phosphate, which enters glycolysis, and the fatty acids are converted into acetyl-CoA through beta-oxidation. 3. Lipogenesis is a process in which excess glycerol and fatty acids are stored in adipose tissue in the form of triglycerides. 4. Lipolysis is a process that breaks down stored triglycerides into glycerol and fatty acids and directs them for lipid catabolism. C. Protein Metabolism (pp. 932–934; Fig. 24.16; Table 24.4) 1. Before amino acids can be oxidized for energy, the amino group must be removed, a process called deamination. 2. The deaminated amino acid molecule is converted to pyruvic acid or a keto acid intermediate of the Krebs cycle. 3. Deaminated amino acids can also be converted back into glucose and contribute to gluconeogenesis. 4. Amino acids are the main anabolic nutrients and can be used to synthesize structural and functional proteins in the body. Copyright © 2010 Pearson Education, Inc.

Chapter 24

Nutrition, metabolism and regulation of body temperature

4. Metabolic states of the body (pp. 935-941; Figs. 24.17-24.22; Boxes 24.5-24.6) A. Catabolic-anabolic body at steady state (pp. 935-936; Figs. 24.17-24.18; Box 24.5) 1 There is a dynamic catabolic-anabolic state of the body in which molecules are broken down and rebuilt. 2. The body extracts molecules to meet these needs from several groups of nutrients: amino acids, carbohydrates and fat stores. B. During the absorption state, anabolism overcomes catabolism (pp. 936-938; Figs. 24.19-24.20). 1. All absorbed monosaccharides are converted into glucose by the liver and released into the blood or converted into glycogen or fat. 2. Most fats enter the lymph as chylomicrons, which are broken down into glycerol and fatty acids for passage into the capillaries. a. Fat cells, skeletal and cardiac muscle cells, and the liver use triglycerides to synthesize plasma proteins, while most of the amino acids that pass through the liver remain in the blood to be taken up by other cells in the body. C. In the postabsorptive state, the net synthesis of fat, glycogen, and protein ceases and the body switches to catabolism of these molecules (pp. 938-941; Figs. 24.21-24.22; Table 24.6). 1. Blood glucose is obtained by promoting glycogenolysis in liver and skeletal muscle, lipolysis in liver and adipose tissue, and cellular protein catabolism. 2. When the body fasts for an extended period, it enters glucose economy, the goal of which is to conserve blood sugar by encouraging greater use of non-carbohydrate fuel molecules, particularly triglycerides. a. If the fast lasts no more than four to five days, the brain continues to use glucose, at which point it begins using ketone bodies as an alternative source of energy. 3. Hormonal controls of the postabsorptive state inhibit insulin release and promote glucagon release, which stimulates an increase in blood glucose levels and causes increased glycogenolysis, lipolysis, and gluconeogenesis.

V. The metabolic role of the liver (pp. 941-944; Fig. 24.23; Table 24.7) A. Cholesterol metabolism and regulation of blood cholesterol levels (pp. 943-944; Fig. 24.23) 1. Cholesterol to which it is transported the blood is bound to lipoprotein complexes that solubilize lipids and regulate entry and exit to specific target cells. 2. Lipoprotein complexes vary in the percentage of lipids they contain, but all contain triglycerides, phospholipids, and cholesterol in addition to protein. 3. The higher the lipid content in lipoproteins, the lower their density, in the case of very low-density lipoproteins (VLDL), low-density lipoproteins (LDL) and high-density lipoproteins (HDL). a. VLDL transports triglycerides from the liver to peripheral tissues, LDL transports cholesterol to peripheral tissues, and HDL transports excess cholesterol from peripheral tissues to the liver and delivers cholesterol to steroid-producing organs. 4. High levels of HDL are considered beneficial because the cholesterol they contain is designed to be excreted, but high levels of LDL are considered risky because the cholesterol they contain can build up on the walls of blood vessels and form plaques.

Copyright © 2010 Pearson Education, Inc.

297

298

Text and Media Human Anatomy and Physiology Teacher's Guide 5. Blood cholesterol is regulated in part by negative feedback, and high cholesterol intake somewhat inhibits cholesterol synthesis in the liver. 6. Diets high in saturated fats stimulate hepatic synthesis of cholesterol and reduce its removal from the body, while unsaturated fatty acids increase excretion of cholesterol into the bile for removal from the body.

SEEN. Energy Balance (pp. 944-954; Figs. 24.24-24.27) A. There is a balance between the body's energy intake, defined as the energy produced during the oxidation of food, and the energy production, which includes the energy consumed by the Heat is lost in the form of energy. , used to do work or stored as fat or glycogen (pp. 944-945). 1. When energy intake and energy expenditure are in balance, body weight remains stable, but when this is not the case, weight is gained or lost. B. Obesity is defined as a person with a body mass index (BMI) greater than 30 (p. 945). 1. BMI = Weight (lbs) × 705/Height (inches)2 2. Obesity increases risk of atherosclerosis, diabetes mellitus, hypertension, heart disease and osteoarthritis. C. Regulation of food intake (pp. 945-947; Fig. 24.24) 1. The hypothalamus produces several peptides that control eating behavior and ultimately reflect two sets of neurons: one that promotes hunger and the other that promotes hunger promotes satiety. 2. The short-term regulation of food intake involves neural signals from the digestive tract, blood levels of nutrients and gastrointestinal hormones. 3. Long-term regulation of food intake depends on the hormone leptin secreted by fat cells. a. Leptin is a hormone released in response to increased body fat mass that suppresses the activity of neurons that promote hunger while increasing the activity of neurons that promote satiety. 4. Other factors that can influence foraging behavior are changes in ambient temperature, stress, other psychological factors, infections, lack of sleep or the composition of the gut bacteria. D. Metabolic Rate and Heat Production (pp. 947-949) 1. The body's rate of energy production is called the metabolic rate. 2. The basal metabolic rate reflects the amount of energy required to carry out only the body's essential activities and is expressed in kilocalories per square meter of body surface area. 3. Factors that affect basal metabolic rate include body surface area, age, gender, stress and hormones. a. The most important factor is surface area due to its influence on body heat loss. 4. The basal metabolic rate is higher when the person is young or male and tends to rise and fall with body temperature. 5. The most important hormonal factor affecting the basal metabolic rate is thyroxine, which increases O2 consumption and heat production. E. Body Temperature Regulation (pp. 950-954; Figs. 24.25-24.27) 1. The average body temperature is 37°C and is normally maintained between 35.8 and 38.2°C. 2. Temperature homeostasis maintains body temperature at an optimal level for enzyme activity in the body. Copyright © 2010 Pearson Education, Inc.

Chapter 24

Nutrition, metabolism and regulation of body temperature

3. The core of the body, which includes the organs inside the skull, thoracic and abdominal cavities, has the highest body temperature, while the shell (mainly the skin) has the lowest temperature. 4. Heat exchange between our skin and the external environment occurs through radiative heat flow, conductive heat flow from hotter objects to cooler objects, convective movement of warm air away from the body, and heat loss through evaporation of fluids from the lungs, mouth, mucous membranes, and skin. 5. The hypothalamus contains heat loss and heat gain centers that help regulate physiological and behavioral mechanisms to maintain normal body temperature. 6. Mechanisms that generate heat, maintain or increase core body temperature and include constriction of the skin's blood vessels, tremors, increased metabolic rate, and increased thyroxine release. 7. Mechanisms of heat loss protect the body from excessively high temperatures and include dilatation of skin blood vessels, increased sweating, and behaviors that promote heat loss or reduce heat gain.

VIII. Developmental Aspects of Nutrition and Metabolism (pp. 954-955) A. Inadequate nutrition during pregnancy and the first three years of life seriously impairs brain growth and development, as well as muscle and bone development (p. 954). B. Several genetic disorders affect metabolism, including cystic fibrosis, phenylketonuria, and glycogen storage disease (p. 954). C. With the exception of insulin-dependent diabetes mellitus, genetically normal children rarely have metabolic disorders, but in middle and old age non-insulin-dependent diabetes mellitus becomes a significant problem (p. 954). D. Metabolic rate decreases throughout life, and this decrease can affect the body's ability to digest and absorb nutrients (pp. 954-955).

Cross-references For more information on the topics covered in Chapter 24, see the chapters listed below. 1. Chapter 2: Chemical Bonding; Carbohydrates; lipids; proteins; Water; ATP; oxidation reduction; chemical equations; patterns of chemical reactions; reversibility of reactions; Enzymes 2. Chapter 3: Membrane Transport; Cytoplasm; Mitochondria 3. Chapter 12: Hypothalamus 4. Chapter 13: Receptors 5. Chapter 16: Prostaglandins; growth hormone; sex steroids; glucocorticoids; Diabetes; Insulin; glucagon; Thyroxine 6. Chapter 19: Regulation of Blood Flow 7. Chapter 23: Chylomicrons; Biliary formation 8. Chapter 25: Ketone bodies as abnormal constituents of urine

Teaching Tips 1. To fully understand metabolic pathways, students should review basic chemical concepts in Chapter 2 and cell structure in Chapter 3. Refer the class to specific sections that relate to the lesson topic being discussed. Copyright © 2010 Pearson Education, Inc.

299

300

Text and Media Human Anatomy and Physiology Teacher Guide 2. Emphasize that amino acids and fatty acids have many functions: structural (membranes), functional, and as an energy source (they enter the Krebs cycle as acetyl-CoA). 3. Mention that cholesterol is responsible for membrane fluidity and is the structural basis of steroid hormones. 4. As a point of interest, give the logical meaning of the term anabolic steroid. 5. Show the difference between vitamins and minerals. 6. A chemist's approach to metabolic pathways is often very different from that of a biologist. One of the most effective ways to chart the biochemical pathways of ATP synthesis (from a physiologist's perspective) is to start with a brief overview of the cellular structure (membranes, cytoplasm, mitochondria, etc.) involved in the process. Then give the total output for each step (glycolysis, Krebs cycle, electron transport), followed by a more detailed examination of each step. It is important for students to see the 'big picture' in order to understand the importance of metabolic pathways. 7. Point out that the Krebs cycle is often thought of as part of aerobic respiration, but this step in the pathway does not directly use oxygen. 8. Emphasize that glycolysis occurs with or without the presence of oxygen, so the term anaerobic should be used with caution. 9. Draw and project a diagram of the cell with disproportionately large mitochondria. Label the diagram with the locations of glycolysis, the Krebs cycle, and electron transport. Briefly summarize each step. 10. List possible alternative terms for the Krebs cycle: citric acid cycle (citrate is the first substrate in the cycle), tricarboxylic acid cycle (several intermediates have three carboxyl groups). 11. A diagram of the chemiosmotic mechanism of ATP synthesis is very useful to show electron transport. Draw (in acetate white) a diagram of the phospholipid bilayer, plotting the electron carriers and the ATP synthetase complex, and tracing the path of electron flow. It is helpful if the instructor physically draws the diagram (if time permits), especially if students need to draw and analyze diagrams during the exam. 12. To gauge student understanding, ask lots of questions during the route discussion. For example, ask "What would happen to ATP production if NADH H reduced the cytochrome oxidase complex instead of the NADH dehydrogenase complex?" 13. Remind the class of the different ways nutrients are taken up and transported (lipids in dairy products, carbohydrates and proteins in blood capillaries). Little reminders help keep chemistry connected to biological processes. 14. Remind the class that deamination of amino acids is necessary for the carbon "backbone" to enter metabolic pathways. Nitrogen compounds are metabolic waste products whose removal is discussed in Chapter 25. 15. When discussing heat control mechanisms, point out that heat can be thought of as flowing down its "concentration gradient." 16. Reinforce the concept of the reflex arc by presenting material on hypothalamic control of body temperature.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Using the Dubois body surface area diagram, students can make rough estimates of basal metabolic rate by calculating respiratory rate and body surface area.

Copyright © 2010 Pearson Education, Inc.

Chapter 24

Nutrition, metabolism and regulation of body temperature

3. Use a small portable fan and a bowl of water to demonstrate the mechanics of body cooling. 4. Use laminated posters showing the different metabolic pathways as you discuss them.

Critical Thinking/Discussion Points 1. Discuss the need for a balanced diet. 2. Examine the idea that more vitamins and minerals are lost in the urine of Americans than in the diets of people in many other countries. Discuss overdosing on vitamins etc. from health food stores and other sources, rather than just getting vitamins and minerals from food. 3. Discuss the different metabolic disorders and relate each to the nutritional deficiency that causes the disorder. 4. Review the differences between fat-soluble and water-soluble vitamins and why caution is needed when using vitamins as dietary supplements. 5. Why are there so many steps in the complete oxidation of glucose (ie why not just one step)? 6. Discuss the consequences (in terms of ATP production) if NADH H reduces the cytochrome b-c1 complex instead of the NADH dehydrogenase complex.

Library Research Topics 1. Examine the differences and importance of low-density and high-density lipoproteins. 2. Examine the effects of the inability to sweat. 3. Examine the effects of a liquid protein diet on the body. 4. Research the different types of popular diets that are currently being advertised. Note the differences, similarities, and side effects, if any. 5. Examine the types of metabolic disorders that affect the different stages of aerobic respiration.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all of the chapter-specific online media resources for Chapter 24 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 24.1 Diet and Nutrition (pp. 911-918) Section 24.2 Overview of Metabolic Reactions (pp. 918-922) Section 24.3 Metabolism of Important Nutrients (pp. 922-934) Memory Game: Nutrition and Metabolism Memory Game: Metabolic Processes

Copyright © 2010 Pearson Education, Inc.

301

302

Text and Media Human Anatomy and Physiology - Teacher Guide Section 24.4 Metabolic States of the Body (pp. 935-941) MP3 Tutorial Session: Energy Production - Case Study: Diabetes Mellitus Section 24.5 The Metabolic Role of the Liver (pp. 941 )-944 ) Section 24.6 Energy Balance (pp. 944–954) Section 24.7 Developmental Aspects of Nutrition and Metabolism (pp. 954–955) Chapter Summary Crossword 24.1 Crossword 24.2 Crossword 24.3 Web Links Chapter Quiz Quiz Quiz Art Labeling Matching Test Multiple Choice Quiz True-False Chapter Quiz Practice Test Learning Tools Histology Atlas myeBook Index Cards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1. Cellular respiration (FHS; series of 6 parts, 10 min each). The series traces cellular respiration by examining the essential fuels and machines that sustain life. It tracks the breakdown of glucose by glycolysis, the Krebs cycle, and oxidative phosphorylation. Finally, connect these processes to nutrition. 2. Free Radicals (FHS; 30 min., 1996). Free radicals are an important weapon in the immune system, but they can also trigger chemical reactions that lead to fatty acid damage, DNA mutations, and protein destruction. 3. Basic human nutrition (IM; 36 min., 1996). Studies how nutrients help in cell maintenance, metabolic regulation, and energy production. Explain the role of carbohydrates, lipids, proteins, vitamins, minerals and water in human nutrition. 4. Human Nutrition: Macro and Micronutrients (IM; 93 min., 2001). This 5-disc DVD set covers simple and complex carbohydrates, describes the beneficial and harmful properties of fat, looks at the role of protein in the immune system, and examines the role of a variety of vitamins and minerals in the human diet.

Copyright © 2010 Pearson Education, Inc.

Chapter 24

Nutrition, metabolism and regulation of body temperature

5. Proteins (FHS; 37 min, 1994). This program provides information about the structure and many of the functions of proteins, including their role in reproduction and catalytic biochemical reactions. 6. Metabolism and Nutrition (FHS; 10 min, 1988). This program investigates the role of ATP in biological systems. The interaction of the three food groups in the processes of cellular respiration is presented in the context of human nutrition.

Software 1. Cellular Respiration CD-ROM (WNS; Win/Mac). Important and intricate cellular processes are brought to life with special effects and animation sequences. Includes oxidation-reduction reactions, fermentation and the Krebs cycle. 2. Nutrition (FHS; Win/Mac). Examines nutrition and the components of a healthy diet and defines the problems and effects of poor nutrition, unhealthy nutrition and nutritional imbalances in humans and animals. Food is broken down into its chemical components: carbohydrates, starches, proteins and vitamins.

Material to improve the lesson Thumbnails of all illustrations in Chapter 24 can be found in Appendix B.

Index Instructor Slide/Resource DVD Image Image Image Image Image

24,1 24,2 24,3 24,4 24,5

Figure Figure Figure Figure Figure

24,6 24,7 24,8 24,9 24,10

Figure Figure Figure Figure Figure

24,11 24,12 24,13 24,14 24,15 24,16

Figure Figure Figure Figure Figure

24,17 24,18 24,19 24,20 24,21

Figure 24.22 Figure 24.23

food pyramids. Essential Amino Acids. Three stages of metabolism of energy-containing nutrients. phosphorylation mechanisms. During cellular respiration, ATP is formed in the cytosol and mitochondria. The three main phases of glycolysis. Simplified version of the Krebs cycle (citric acid). Mechanism of oxidative phosphorylation. Electronic energy gradient in the electron transport chain. Atomic force microscopy shows the structure of the rotor rings of the energy-converting ATP synthase. Structure of ATP synthase. Energy production during cellular respiration. Glycogenesis and Glycogenolysis. Initial phase of lipid oxidation. triglyceride metabolism. Oxidative transamination and deamination and keto acid modification: processes that occur when amino acids are used for energy. Pools of carbohydrates, fats and amino acids. Conversion of carbohydrates, fats and proteins. Main events and main metabolic pathways of absorption state. Insulin drives almost all events into the absorption state. Main events and main metabolic pathways of the postabsorptive state. Glucagon is a hyperglycemic hormone that causes blood sugar levels to rise. Approximate composition of lipid-bearing lipoproteins in body fluids. Copyright © 2010 Pearson Education, Inc.

303

304

Text and Media Teacher's Manual of Human Anatomy and Physiology Figure 24.24 Figure 24.25

Model for the hypothalamic drive of appetite and food intake. Body temperature remains constant as long as heat production and heat loss are balanced. Figure 24.26 Heat exchange mechanisms. Fig. 24.27 Body temperature regulation mechanisms. Table 24.1 Summary of carbohydrate, lipid and protein nutrients Table 24.2 Vitamins Table 24.3 Minerals Table 24.4 Thumbnail view of metabolic reactions Table 24.5 Profiles of major body organs on fuel metabolism Table 24.6 Summary of normal hormonal influences on metabolism Table 24.7 Summary of functions Metabolic functions of the liver More precisely looked obesity: In search of the miracle cure

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 16. Cellular respiration is a set of reactions that break down (oxidize) glucose, fatty acids, and amino acids in the cell. Part of the energy released is used to synthesize ATP. FAD and NAD act as reversible hydrogen acceptors, providing accepted hydrogen to the electron transport chain. (pp. 919-920) 17. Glycolysis occurs in the cytoplasm of cells. It can be divided into three main events: (1) activation of the sugar, (2) cleavage of the sugar, and (3) oxidation and formation of ATP. During sugar activation, glucose is phosphorylated, converted to fructose, and rephosphorylated to produce fructose-1,6-diphosphate; Two ATP molecules are used. These reactions provide the activation energy for the subsequent events of glycolysis. During sugar cleavage, fructose 1,6-diphosphate splits into two 3-carbon fragments: glyceraldehyde 3-phosphate or dihydroxyacetone phosphate. During the oxidation and formation of ATP, the 3-carbon molecules are oxidized by removing hydrogen (which is absorbed by NAD). The inorganic phosphate groups attached to each oxidized fragment by high-energy bonds are cleaved, absorbing enough energy to form four ATP molecules. The end products of glycolysis are two molecules of pyruvic acid, two molecules of reduced NAD, and a net gain of two molecules of ATP per molecule of glucose. (pp. 923-924) 18. Pyruvic acid is converted to acetyl-CoA, which enters the Krebs cycle. In order for pyruvic acid to be converted to acetyl-CoA, the following must take place: decarboxylation to remove a carbon, oxidation to remove hydrogen atoms, and combination of the resulting acetic acid with coenzyme A to produce acetyl-CoA. (p. 924) 19. Glycogenesis is the process by which glucose molecules join together in long chains to form glycogen. Gluconeogenesis is the formation of new sugars from molecules other than carbohydrates. Lipogenesis is the term for the synthesis of triglycerides. a. Glycogenesis (and perhaps lipogenesis) is likely to occur after a high carbohydrate meal. B. Gluconeogenesis is likely to occur just before waking up in the morning. (pp. 929-930) 20. Metabolic acidosis due to ketosis is the result of excessive burning of fat for energy. Hunger, reckless dieting, and diabetes mellitus can lead to ketosis. (p. 932) Copyright © 2010 Pearson Education, Inc.

Chapter 24

Nutrition, metabolism and regulation of body temperature

21

(Video) Marathon Class | SKELETAL SYSTEM (कंकाल तंत्र ) BY KAJAL MA'AM #futuretimescoaching #skeletalsystem

(p. 937) 22. HDL function to transport cholesterol from peripheral tissues to the liver. LDL transports cholesterol to the peripheral tissues. (p. 943) 23. Factors affecting plasma cholesterol levels include diet (through cholesterol and/or saturated fat intake), smoking, drinking and stress. Sources of cholesterol in the body include eating animal foods and the production of acetyl coenzyme A in the liver (and intestinal cells). Cholesterol is lost from the body when it is catabolized and secreted into bile salts, which are eventually excreted in the feces. It is used by the body's cells in plasma membranes and in the synthesis of vitamin D and steroid hormones. (p. 944) 24. "Body energy balance" means that energy intake equals total energy output. If the body is not in exact balance, weight will be gained or lost. (p. 944) 25. Metabolic rate increases with increased thyroxine production. Eating increases metabolic rate, an effect called chemical thermogenesis. A higher body surface area to body volume ratio requires a higher metabolic rate because the heat exchange surface area is larger. Muscle training and emotional stress increase metabolic rate. Hunger slows down your metabolism. (pp. 947-948) 26. The center of the body includes organs within the skull and the thoracic and abdominal cavities. The core has the highest temperature. The bark or skin has the lowest temperature. The blood serves as a heat carrier between the core and the shell. (p. 950) 27. Mechanisms that promote heat to maintain or increase body temperature include vasoconstriction in the carapace, which inhibits radiative heat loss; conduction and convection; increased metabolic rate due to the release of epinephrine; and tremors. Mechanisms of heat loss include vasodilation of blood vessels in the skin and sweating (which increases evaporative heat transfer). Whenever core temperature rises above or below normal, the peripheral and central thermoreceptors send information to the hypothalamus. Like a thermostat, the hypothalamus responds to inputs by initiating the appropriate reflex mechanisms of heat promotion or heat loss through autonomic effector pathways. (pp. 950–953)

Critical Thinking Questions and Clinical Applications 1. The number of ATP molecules resulting from the complete oxidation of a given fatty acid can be easily calculated by counting the number of carbon atoms in the fatty acid and dividing by two to get the number of Determine acetyl molecules. produced. In our example, an 18-carbon fatty acid produces 9 molecules of acetyl-CoA. Since everyone produces 12 ATP molecules per Krebs cycle, the oxidative pathways yield a total of 108 ATP molecules: 9 from the electron transport oxidation of 3 NADH H, 2 from the oxidation of 1 FADH2, and a net yield of 1 ATP during the Krebs cycle. In addition, any Acetyl-CoA released during the beta period is Copyright © 2010 Pearson Education, Inc.

305

306

Text and media guide to human anatomy and physiology

2.

3.

4.

5.

6.

The oxidation creates an additional molecule of NADH H and FADH2, which upon re-oxidation produces a total of 5 more ATP molecules. With an 18-carbon fatty acid, this would happen 8 times, producing 40 more ATP molecules. After subtracting the ATP needed to start the process, that gives a grand total of 147 ATP molecules from that single 18-carbon fatty acid! (pp. 928–929, 931) Hypothermia is an abnormally low body temperature. It kills by lowering body temperature below the relatively narrow range where biochemical reactions can occur. Older people have less subcutaneous tissue. Also, your metabolic rate (and your ability to generate heat) is slower. (p. 953) When diagnosed with high cholesterol and severe atherosclerosis, he should avoid foods containing saturated fat and avoid eating eggs and large amounts of red meat. You should replace foods that contain unsaturated fatty acids and include fish in your diet. You should also quit smoking, reduce coffee, avoid stressful situations if possible, and increase the amount of aerobic exercise. (p. 944) The chemiosmotic machinery is concerned with the operation of the electron transport chain and the generation of the proton gradient, during which most of the ATP is collected in the mitochondria. When decoupled, cells use more and more nutrients to create the necessary ATP, leaving fewer "calories" for protein synthesis and tissue maintenance. (pp. 922, 925-928) Simon shows signs of vitamin C deficiency, also known as scurvy. Although he has rich sources of many nutrients on his island, his diet is deficient in fruits and green leafy vegetables as a source of vitamin C. (p. 917) Gregor's blood tests showed likely high cholesterol and triglyceride levels. It's a good idea to limit saturated fats like meat and butter. The fat in cottage cheese is also saturated and should be eaten in moderation. Gregor should increase his intake of unsaturated fats like olive oil and also add omega-3 fatty acids from fish. Gregor can substitute soy proteins for animal proteins to further lower his cholesterol levels. In addition to the dietary changes, Gregor needs to start exercising to further lower his levels and help with his "poor" blood levels. (p. 944)

Recommended reading Brady, Roscoe O. and R. Schiffmann. "Enzyme replacement therapy for metabolic storage disorders". Lancet Neurology 3 (12) (December 2004): 752-756. Christensen, Damaris. "Dirty Discoveries". Science News 159(15) (April 2001): 238-239. Dallongeville, J., et al. Alabama. "The association of metabolic disorders with metabolic syndrome is different in men and women." Annals of Nutrition & Metabolism 48(1) (January/February 2004): 43–50. Dulloo, Abdul G. "A Comprehensive Defense Against Obesity." Science 297 (5582) (Aug 2002): 780–781. Flier, Jeffrey S. "The Missing Link in Obesity?" Nature 409 (6818) (January 2001): 292–293. Friedman, Jeffrey. "Smear in the wrong places." Nature 415 (6869) (January 2002): 268–269. Hotamisligil, Gökhan S. "Inflammation and Metabolic Disorders." Nature 444 (7121) (2006 December): 860-867. Pradhan, Aruna. "Obesity, metabolic syndrome, and type 2 diabetes: inflammatory basis of glucose metabolism disorders". Nutrition Reviews 65(3) (December 2007): S152-S156. Ioannou, Yiannis A. "Multi-drug permease and subcellular cholesterol transport." Nature Reviews: Molecular Cell Biology 2 (9) (September 2001): 657-668.

Copyright © 2010 Pearson Education, Inc.

Chapter 24

Nutrition, metabolism and regulation of body temperature

Maid, Thomas. "Down with the bad guys, long live the good." Scientific American 286(2) (February 2002): 32-33. Millington, David S. "Newborn Screening for Metabolic Diseases." American Scientist 9 (1) (January/February 2002): 40-47. Rader, Daniel J. "A New Feature on the Cholesterol Lowering Landscape." Nature Medicine 7 (12) (December 2001): 1282-1284. Seppa, N. "Poor appetite in the elderly associated with hormones." Science News 160 (December 2001): 390. Tatar, Marc and David M. Rand. "Q Diet Tips". Science 295 (5552) (January 2002): 54-55. Taubes, Gary. "The Gentle Science of Dietary Fat". Science 291 (5513) (March 2001): 2536-2545. Travis, John. "The hunger hormone?" Science News 161(7) (February 2002): 107-108. Vidal-Puig, Antonio and S. O'Rahilly. "Control of the Glucose Factory". Nature 413 (6852) (2001 Sep): 125-126. Wang, L. "Vegetables Prevent Cancer Through Essential Proteins." Science News 159(14) (March 2001): 182. Yoshida, M., E. Muneyuki and T. Hisabori. "ATP Synthase: A Wonderful Spin Cell Engine". Nature Reviews: Molecular Biology 2 (September 2001): 669-677.

Copyright © 2010 Pearson Education, Inc.

307

25

the urinary system

Goals

Urine

Anatomia do Rim

12. Describe the normal physical and chemical properties of urine. 13. List several abnormal components of urine and state the condition characterized by the presence of detectable amounts of each.

1. Describe the gross anatomy of the kidney and its lining. 2. Monitor the blood supply through the kidney. 3. Describe the anatomy of a nephron.

Physiology of the renal ureters: mechanisms of urination 4. Describe the forces (pressures) that promote or counteract glomerular filtration. 5. Compare intrinsic and extrinsic glomerular filtration rate controls. 6. Describe the mechanisms underlying the reabsorption of water and solutes from the renal tubules into the peritubular capillaries. 7. Describe how sodium and water reabsorption are regulated in the distal tubule and collecting duct. 8. Describe the importance of tubular secretion and list some substances that are secreted. 9. Describe the mechanisms responsible for the medullary osmotic gradient. 10. Explain the formation of dilute versus concentrated urine. 11. Define renal clearance and explain how this value summarizes how the kidneys handle a substance.

14. Describe the general location, structure and function of the ureters. Bladder 15. Describe the general location, structure and function of the urinary bladder. Urethra 16. Describe the general location, structure and function of the urethra. 17. Compare the course, length and function of the male and female urethra. Urination 18. Define urination and describe its neural control. Aspects of the development of the urinary system 19. Follow the embryonic development of the urinary organs. 20. List several age-related changes in the anatomy and physiology of the urinary system.

Suggested Lesson Plan I. Anatomy of the Kidney (pp. 961-969; Figs. 25.1-25.8) A. Location and External Anatomy (pp. 961-962; Figs. 25.1-25.2) 1. The kidneys are shaped organs found retroperitoneally become in the upper lumbar region. 2. The medial surface is concave and has a renal hilum that opens into a renal cavity where blood vessels, nerves, and lymphatics are located.

308 Copyright © 2010 Pearson Education, Inc.

Chapter 25

the urinary system

3. The kidneys are surrounded by an external renal fascia that anchors the kidney and adrenal gland to surrounding structures, a perirenal fat pad that surrounds and cushions the kidney, and a fibrous capsule that prevents surrounding infection from reaching the kidney. B. Internal Anatomy (pp. 962-963; Fig. 25.3) 1. There are three distinct regions of the kidney: the cortex, the medulla, and the renal pelvis. 2. The major and minor calyxes collect urine and empty it into the renal pelvis. C. Blood and Nerve Supply (pp. 963-964; Fig. 25.4) 1. The blood supply to and from the kidneys is via the renal arteries to the cortex to the radial segmental, lobular, interlobar, arch and cortical arteries. and vice versa for the renal veins of the radial, arcuate and interlobular cortical veins. 2. The renal plexus regulates renal blood flow by adjusting the diameter of the renal arterioles and affecting the role of the nephrons in urine formation. D. Nephrons are the structural and functional units of the kidneys that perform the urinary processes (pp. 964-969; Figs. 25.4-25.8). 1. Each nephron consists of a renal corpuscle composed of a capillary tuft (the glomerulus) surrounded by a glomerular capsule (Bowman's capsule). 2. The renal tubule begins in the glomerular capsule as a proximal convoluted tubule, continues through a hairpin loop, the loop of Henle, and becomes a distal convoluted tubule before emptying into a collecting duct. 3. The collecting ducts collect the filtrate from many nephrons and pass through the renal pyramid to the renal papilla, where they open into a small calyx. 4. There are two types of nephrons: 85% are cortical nephrons, almost exclusively located in the cortex; 15% are juxtamedullary nephrons, located near the cortex-medullary junction. 5. Peritubular capillaries arise from efferent arterioles that drain the glomerulus and absorb solutes and water from the tubules. 6. Blood flow in the renal circulation is subject to high resistance in the afferent and efferent arterioles. 7. The juxtaglomerular apparatus is a structural arrangement between the afferent arteriole and the distal convoluted tubule that forms the granule cells and dense cells of the macula. 8. The filtration membrane sits between the blood and the interior of the glomerular capsule, allowing the free passage of water and solutes.

II. Renal Physiology: Mechanisms of Urine Formation (pp. 969-984; Fig. 25.9-25.18; Table 25.1) A. Step 1: Glomerular Filtration (pp. 969-974; Fig. 25.9-25.12) 1. Glomerular Filtration It is a passive process, a nonselective process in which hydrostatic pressure forces fluid across the glomerular membrane. 2. The net filtration pressure responsible for the formation of the filtrate results from the balance of the glomerular hydrostatic pressure against the combined forces of the colloidal osmotic pressure of the glomerular blood and the capsular hydrostatic pressure exerted by the fluids in the glomerular capsule. 3. The glomerular filtration rate is the volume of filtrate produced by all the glomeruli of the kidneys combined every minute.

Copyright © 2010 Pearson Education, Inc.

309

310

4. It is important to maintain a relatively constant glomerular filtration rate since reabsorption of water and solutes depends on how fast the filtrate flows through the tubules. 5. The glomerular filtration rate is kept relatively constant by intrinsic autoregulatory mechanisms and extrinsic neural and hormonal mechanisms. a. Renal autoregulation utilizes myogenic control over the degree of distension of the afferent arteriole and a tubuloglomerular feedback mechanism that is responsive to filtrate flow rate in the tubules. B. Extrinsic neural mechanisms are stress-induced sympathetic responses that inhibit filtrate formation by contraction of afferent arterioles. C. The renin-angiotensin mechanism causes increased systemic blood pressure and blood volume through increased Na reabsorption. B. Step 2: Tubular resorption (pp. 974-978; Figs. 25.13-25.14, 25.18; Tab. 25.1) 1. Tubular resorption begins as soon as the filtrate enters the proximal convoluted tubule and involves almost complete resorption of organic nutrients and hormone-regulates water and ion absorption. 2. The most abundant cation in the filtrate is Na and reabsorption is always active. 3. Passive tubular reabsorption is the passive reabsorption of negatively charged ions moving along an electrical gradient generated by active Na reabsorption. 4. Mandatory water reabsorption occurs in the water-permeable regions of the tubules in response to osmotic gradients generated by active Na transport. 5. Secondary active transport is responsible for the uptake of glucose, amino acids, vitamins and most cations and occurs when solutes are transported along with Na as it moves along its concentration gradient. 6. Unabsorbed or incompletely absorbed substances remain in the filtrate due to lack of carrier molecules, lipid insolubility or large size (urea, creatinine and uric acid). 7. Different areas of the tubules have different absorption capacities. a. The proximal convoluted tubule is most active in reabsorption and the most selective reabsorption occurs. B. The descending limb of the loop of Henle is permeable to water, while the ascending limb is impermeable to water but permeable to electrolytes. C. The Na and water permeability of the distal convoluted tubule and collecting duct is regulated by the hormones aldosterone, antidiuretic hormone and atrial natriuretic peptide. C. Step 3: Tubular Secretion (p. 978) 1. Tubular secretion removes unwanted solutes, removes solutes that have been reabsorbed, removes excess potassium from the body, and controls blood pH. 2. Tubular secretion is most active in the proximal convoluted tubule but also occurs in the collecting ducts and distal convoluted tubules. D. Regulation of Urine Concentration and Volume (pp. 978-983; Figs. 25.15-25.18) 1. One of the basic functions of the kidney is to maintain a constant level of solute in body fluids by regulating the concentration and volume of the Urine regulates urine.

Copyright © 2010 Pearson Education, Inc.

Chapter 25

the urinary system

2. The countercurrent mechanism involves the interaction between filtrate flow through the loops of Henle (the countercurrent multiplier) of the juxtamedullary nephrons and blood flow through the vasa recta (the countercurrent exchanger). a. As water is freely absorbed by the descending branch of the loop of Henle, the concentration of the filtrate increases and the water is reabsorbed. B. The ascending branch is permeable to solutes but not to water. C. In the collecting duct, urea diffuses into the deep marrow tissue and contributes to the increased osmotic gradient encountered by the filtrate as it moves through the loop. i.e. The vasa recta help maintain the medulla's strong concentration gradient by circulating salt into the blood as it descends into the medulla and then out again as it rises toward the cortex. 3. Since the tubular filtrate dilutes as it flows through the ascending limb of the loop of Henle, the production of diluted urine is achieved simply by directing the filtrate into the renal pelvis. 4. The formation of concentrated urine occurs in response to the release of antidiuretic hormone, which causes the collecting ducts to leak water and increases water absorption from the urine. 5. Diuretics act by increasing urine output by acting as osmotic diuretics or inhibiting sodium and causing obligatory reabsorption of water. E. Renal Clearance (p. 984) 1. Renal clearance refers to the volume of plasma removed from a given substance over a given period of time. 2. Inulin is used as a clearance standard to determine glomerular filtration rate because it is not absorbed, stored, or excreted. 3. If the clearance value of a substance is lower than that of inulin, part of the substance is absorbed; if the clearance value is greater than the inulin clearance rate, part of the substance is secreted. A clearance value of zero indicates that the substance has been completely absorbed.

3. Urine (pp. 984-985; Table 25.2) A. Physical Characteristics (pp. 984-985) 1. Freshly voided urine is clear and paler to paler due to urochrome, a pigment resulting from the breakdown of hemoglobin deep yellow color . 2. Fresh urine is slightly aromatic but develops an ammonia odor when left to stand due to bacterial urea metabolism. 3. Urine is normally slightly acidic (pH around 6) but can range from 4.5 to 8.0 in response to changes in metabolism or diet. 4. Urine has a higher specific gravity than water due to the presence of solutes. B. Chemical Composition (p. 985; Table 25.2) 1. The volume of urine is approximately 95% water and 5% solutes, with most of the solutes going to the nitrogenous wastes urea, creatinine and uric acid.

4. Ureters (pp. 985-986; Figs. 25.19-25.20) A. The ureters are tubes that actively transport urine from the kidneys to the bladder (pp. 985-986; Fig. 25.19). B. The walls of the ureters consist of an inner mucous membrane continuous with the renal pelvis and bladder, a double layer of muscle, and a fibrous adventitia covering the outer surface (p. 986; Figs. 25-20). Copyright © 2010 Pearson Education, Inc.

311

312

Text and media guide to human anatomy and physiology

V. Bladder (pp. 986-987; Fig. 25.21) A. The urinary bladder is a muscular sac that expands as urine is produced by the kidneys to store the urine until it can be conveniently emptied (p. 986 ; Fig. 25.21). ). B. The bladder wall has three layers: an outer adventitia, a middle layer of detrusor muscle, and a tightly folded inner mucosa to allow expansion of the bladder without a large increase in internal pressure (pp. 986-987).

SEEN. Urethra (pp. 987-988; Fig. 25.21) A. The urethra is a muscular tube that carries urine out of the body; in the female it is 3-4 cm long, in the male it reaches 20 cm (p. 987; Fig. 25.21). B. Two sphincters are associated with the urethra: the internal urethral sphincter, which is involuntary and formed by the detrusor muscle; and the external sphincter of the urethra, which is voluntary and is formed by skeletal muscles in the urogenital diaphragm (p. 987; Fig. 25.21). C. The external orifice of the urethra lies between the clitoris and the vaginal opening in women and at the tip of the penis in men (p. 987; Fig. 25.21).

VIII. Urination (p. 988; Fig. 25.22) A. Urination or micturition is the emptying of the bladder (p. 988; Fig. 25.22). 1. As urine accumulates, expansion of the bladder activates stretch receptors, which activate spinal reflexes, resulting in urine retention. 2. The voluntary triggering of micturition reflexes leads to activation of the pontine micturition center, which sends signals to parasympathetic motor neurons that stimulate contraction of the detrusor muscle and relaxation of the urinary sphincters.

VIII. Developmental Aspects of the Urinary System (pp. 988-991) A. In the developing fetus, mesoderm-derived urogenital crests give rise to three sets of kidneys: the abdominal, mesonephros, and metanephros (pp. 988-989). 1. The pronephros forms and degenerates during the fourth to sixth weeks, but the pronephric duct persists, connecting the later developing kidneys to the cloaca. 2. The mesonephros develops from the pronephric duct, which is then called the mesonephric duct, and persists until the development of the metanephros. 3. The metanephros develops at about five weeks and forms ureteral buds, which give rise to the ureters, renal pelvis, calyces, and collecting ducts. 4. The cloaca is divided into what later becomes the rectum, the anal canal and the urogenital sinus, from which the bladder and urethra arise. B. Newborns urinate more frequently because the bladder is small and the kidneys cannot concentrate urine until 2 months of age (p. 990). C. From 2 months of age to adolescence, urinary output increases to that of an adult (p. 990). D. Voluntary control of the urinary sphincters depends on the development of the nervous system, and complete control of the bladder, even at night, does not usually occur before the age of 4 (p. 991). E. With age, renal function decreases due to the contraction of the kidneys as the size and number of nephrons decrease; the bladder also shrinks and loses tone, resulting in frequent urination (p. 991). Copyright © 2010 Pearson Education, Inc.

Chapter 25

the urinary system

Cross-references For more information on the topics discussed in Chapter 25, see the chapters listed below. 1st 2nd 3rd 4th 5th 6th 7th 8th

9.

Chapter 3: Hydrostatic Pressure and Diaphragms; membrane transport; microvilli Chapter 4: epithelial cells; dense connective tissue Chapter 10: Levator ani Chapter 14: Sympathetic control; parasympathetic pelvic splanchnic nerves; Epinephrine Chapter 16: Activation of Vitamin D; aldosterone; ADH; atrial natriuretic factor; Epinephrine Chapter 17: Erythropoietin; Plasma Chapter 19: Windowed Capillaries; arterioles; autoregulation of blood flow; vascular resistance; fluid dynamics; Renin-angiotensin mechanism Chapter 26: Mechanism of renin-angiotensin in the control of extracellular fluid volume; electrolyte balance; glomerulonephritis; H and HCO3 and renal function; Hypoaldosteronism Chapter 27: Male urethra and semen release

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 40: Anatomy of the urinary system Exercise 41: Urinalysis PhysioEx™ 8.0 Exercise 41B: Physiology of the renal system: computer simulation 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 40: Anatomy of the urinary system Exercise 41: Urinalysis PhysioEx™ 8.0 Exercise 41B: Physiology of the renal system: computer simulation

Teaching Tips 1. Emphasize the retroperitoneal location of the urinary structures. 2. Emphasize the importance of keeping the kidney in a normal position. 3. Use the analogy of a cone-shaped strainer in a glass funnel to illustrate how a pyramid fits into your glass. This gives students a three-dimensional framework to relate to the anatomy of the kidney. 4. Emphasize that the "lines" pointing toward the papilla in the kidney pyramids are the microscopic tubules pointing in that direction. 5. Run a finger over a partially inflated balloon to illustrate the glomerular capsule forming around the glomerulus. 6. Emphasize the kidney's unique microvasculature: arterioles supply and empty the glomerulus. 7. Students often confuse the different capillary beds of the kidney. Emphasize the difference between the glomerulus, peritubular capillaries, and vasa recta. 8. Emphasize that the filtration membrane is actually made up of two layers of cells plus a protein layer, and not a single phospholipid bilayer as some students believe.

Copyright © 2010 Pearson Education, Inc.

313

314

Text and Media Human Anatomy and Physiology Teacher Guide 9. Point out that glomerular capillaries have a relatively constant rate of blood flow, unlike most capillary beds in the body, where blood flow is altered relative to the metabolic needs of the tissues they serve , and that there are several regulatory mechanisms designed to ensure that stability. Emphasize that maintaining a constant flow rate ensures that the rate of movement of fluid through the nephron does not fluctuate with small changes in systemic arterial pressure. 10. Establishing a reference point is essential for the student to understand renal system terminology. Students often have problems with reabsorption versus secretion: "Does the tubule secrete into the blood?" Make sure the class uses the epithelial cells (or blood cells) of the tubules as a reference point when using the terms secretion and reabsorption. Another potential source of confusion is secretion vs. excretion. 11. Emphasize that ADH and aldosterone are hormones that individually address two entirely different problems in the kidneys. When used together, they can maximize water and Na+ retention by the nephron, but are often used individually to address Na+ or water retention issues alone. 12. Emphasize that a physiological sphincter prevents backflow of urine into the ureters; the ureters enter the bladder wall at such an angle that the volume and pressure in the bladder increase; The pressure forces the openings of the ureter to collapse, preventing the urine from moving backwards. Use a diagram to illustrate this mechanism as it is difficult for most students to visualize. 13. Mention the similar function of bladder folds as stomach folds. 14. Emphasize that the urinary system is one of the few places in the body that contains transitional epithelium.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. If possible, have someone from a local kidney dialysis center talk to the class about how the artificial kidney works and other aspects of the dialysis process. 3. Show a hydrometer and other materials used to perform a urinalysis. Discuss the importance of urinalysis in routine examination and pathological diagnosis. 4. Use a torso model and/or stuffed animal model to show the urinary organs. 5. Use a funnel and filter paper to demonstrate the filtration process in the renal corpuscle. 6. Prepare a dialysis bag to show ion exchange based on osmolarity. 7. Use a longitudinal section model of the kidney to identify key anatomical features. If the nephron is part of the model or available, demonstrate the anatomical regions of the nephron and describe the specific functions of each area.

Critical Thinking/Discussion Points 1. Discuss the connection between emotions and kidney function. 2. Study the effects of certain medications on kidney function. 3. Explain why doctors tell a sick person to drink plenty of fluids and why fluid intake and expenditure is so carefully controlled in the hospital. 4. Discuss how kidney stones form, why they form, and how they can be treated.

Copyright © 2010 Pearson Education, Inc.

Chapter 25

the urinary system

5. Examine the mechanism of thirst and relate it to renal physiology. 6. Identify the role of the kidneys in regulating blood pressure. 7. Discuss the different types of kidney inflammation/infection and the consequences for other body systems.

Library Research Topics 1. Study the effects of common drugs such as penicillin, myceine, etc. on kidney function. 2. Study the effects of antihypertensive drugs on renal function. 3. Examine the effect of circulatory shock on kidney function and explain why the kidneys are affected. 4. Find out about available treatments for kidney stones. 5. Examine the dialysis process. 6. Find out about the latest incontinence treatments. 7. Describe recent advances in the role of atrial natriuretic factor in fluid and electrolyte balance. 8. To study the effects of the urinary system on a child born with congenital adrenal hyperplasia (CAH) and treat this specific problem.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all chapter-specific online media resources for Chapter 25 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 25.1 Anatomy of the Kidney (pp. 961-969) Physiology® 10 System Interactive Game: Urinary System: Anatomy Overview Art Label: The Urinary System (Fig. 25.1, p. 961) Art Label: Internal Anatomy of the Kidney Kidney (Fig. 25.3b , p. 963) Artist's Caption: Location and Structure of the Nephrons (Fig. 25.5, p. 965) Section 25.2 Renal Physiology: Mechanisms of Urine Production (pp. 969–984) Tutor Session MP3 : Urine Production Physiology® 10-System Interactive Suite – Glomerular Filtration Physiology® 10-System Interactive Suite - Early Filtrate Processing Physiology® 10-System Interactive Suite - Late Filtrate Processing PhysioEx™ 8.0 - Renal System Physiology Case Study: Diabetic Nephropathy (Kidney Damage) Case Study: Kidney Failure Section 25.3 Urine (pp. 984-985) Section 25.4 Ureters (pp. 985–986)

Copyright © 2010 Pearson Education, Inc.

315

316

Text and media Teacher's manual of human anatomy and physiology Section 25.5 Bladder (pp. 986-987) Section 25.6 Urethra (pp. 987-988) Memory game: The urinary system in situ Section 25.7 Urination (p. 988) Study case study : Urinary frequency (polyuria) and excessive thirst (polydipsia) Section 25.8 Developmental Aspects of the Urinary System (pp. 988–991) Chapter Summary Crosswords 25.1 Crosswords 25.2 Web Links Chapter Tests Artist Identification Test Matching Test Multiple Choice True-False Quiz Chapter Practice Quiz Study Tools Histology Atlas myeBook Flashcards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1. The Human Urinary System (BC; 23 min., 1999). This video gives an overview of how the human urinary system works. 2. The kidney (FHS; 15 min, 1996). This program from the Living World series covers the structure and function of the kidneys and how they help maintain homeostasis. 3. Kidney disease (FHS; 26 min, 1990). This video from The Doctor Is In series looks at ESRD (End Stage Renal Disease) and its causes, as well as the difficulties associated with transplants. 4. Kidney transplantation (FHS; 45 min, 1995). This video shows a living kidney transplant from a son to his father with matching tissue. 5. The urinary tract: water! (FHS; 28 minutes, 1984). This video from the award-winning The Living Body series shows the vital role water plays in how the body functions and how it keeps it in balance. 6. Function of the kidneys (IM; 23 min, 1988). This program examines how a kidney regulates homeostasis.

Copyright © 2010 Pearson Education, Inc.

Chapter 25

the urinary system

A.D.A.M.® Interactive Anatomy® 4.0 software (see full list on page 9 of this manual). A.D.A.M.® MediaPro (see page 9 of this manual for a complete list). A.D.A.M.® Anatomy Practice (see page 87 of this manual for a complete list). Fluids and Electrolytes CD-ROM (NIMCO; Windows). Teaches over 200 basic fluid and electrolyte concepts. 5. Physiology® 10 System Interactive Set: Urinary System (BC; Win/Mac). Interactive software with Urinary System and Fluid and Electrolytes sections that explore the physiology of the urinary system and its impact on fluid and electrolyte balance. 6. Practice Anatomy Lab™ 2.0: Human cadaver, anatomical models, histology, cat, fetal pig (see full list on page 9 of this manual). 7. The Ultimate Human Body, version 2.2 (see page 9 of this manual for the full list). 1st 2nd 3rd 4th

Materials to Improve Teaching Thumbnails of all figures in Chapter 25 can be found in Appendix B.

Index Instructor Slide/Resource DVD Image Image Image Image Image Image Image Image

25,1 25,2 25,3 25,4 25,5 25,6 25,7 25,8 25,9 25,10

Figure 25.11 Figure 25.12 Figure Figure Figure Figure

25,13 25,14 25,15 25,16

Figure 25.17 Figure 25.18 Figure 25.19 Figure 25.20 Figure 25.21 Figure 25.22 Figure 25.23 Table 25.1 Table 25.2

The urinary system. Location of the kidneys on the posterior body wall. Internal anatomy of the kidney. blood vessels of the kidney. Location and structure of the nephrons. renal cortical tissue and renal tubules. Blood vessels of the cortical and juxtamedullary nephrons. Juxtaglomerular apparatus (JGA) of a nephron. The filter membrane. An unrolled schematic nephron showing the three major kidney processes that adjust plasma composition. Forces governing glomerular filtration and filtration pressure. Physiological mechanisms that regulate glomerular filtration rate (GFR) in the kidneys. Transcellular and paracellular pathways of tubular reabsorption. Reuptake by PCT cells. Osmotic gradient in the renal medulla. Countercurrent mechanism to establish and maintain the medullary osmotic gradient. Mechanisms of formation of diluted and concentrated urine. Summary of tubular reabsorption and secretion. pyelogram. Section through the ureteral wall (10). Structure of the bladder and urethra. control of urination. Development of the urinary system of the embryo. Absorption capacities of different segments of the renal tubules and collecting ducts for abnormal urinary components

Copyright © 2010 Pearson Education, Inc.

317

318

Text and media guide to human anatomy and physiology

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 11. The perineal fat pad helps hold the kidney in place against the posterior wall of the trunk and protects it from impact. (p. 962) 12. A creatine molecule follows the following path from a glomerulus to the urethra. It first passes through the glomerular filtration membrane, a porous membrane composed of a fenestrated capillary endothelium, a thin basement membrane, and the visceral membrane of the glomerular capsule, which is made up of podocytes. The creatine molecule then passes through the proximal convoluted tubule, loop of Henle and distal convoluted tubule and into the collecting duct where it travels via the renal pyramids to the medulla. From the medulla, the molecule enters the renal pelvis and exits the kidney through the ureter. It then travels to the urinary bladder and then to the urethra. (pp. 964-966; 985-987) 13. Kidney filtrate is a solute-rich liquid without blood cells or plasma proteins because the filtration membrane is water permeable and all solutes are smaller than plasma proteins. The capillary endothelium restricts the passage of formed elements, while the anion-rich basement membrane retains most proteins and some smaller anionic molecules. (p. 971) 14. The mechanisms contributing to renal autoregulation are the myogenic mechanism and the tubuloglomerular feedback mechanism. The myogenic mechanism reflects the tendency of vascular smooth muscle to contract when stretched. An increase in systemic blood pressure causes the afferent arterioles to constrict, impeding blood flow to the glomerulus and preventing glomerular blood pressure from rising to harmful levels. On the other hand, a decrease in systemic arterial pressure causes afferent arterioles to dilate and glomerular hydrostatic pressure to increase. Both responses help maintain normal GFR. The tubuloglomerular mechanism reflects the activity of cells in the macula densa in response to a slow filtration rate or low filtrate osmolarity. When activated, they release chemicals that cause vasodilation in the afferent arterioles. Renal autoregulation keeps renal blood flow relatively constant over a blood pressure range of about 80 to 180 mmHg, thereby avoiding large changes in water and solute excretion. (p. 972) 15. Sympathetic nervous system controls protect the body during extreme stress by redirecting blood to more vital organs. Strong sympathetic stimulation causes release of norepinephrine at alpha-adrenergic receptors, causing strong vasoconstriction of renal arterioles. This leads to a drop in glomerular filtration and indirectly stimulates another extrinsic mechanism, the renin-angiotensin mechanism. The renin-angiotensin mechanism involves the release of renin from juxtaglomerular granule cells, which enzymatically converts angiotensinogen to angiotensin I in plasma globulin. Angiotensin I is subsequently converted to angiotensin II by angiotensin converting enzyme (ACE) produced by the capillary endothelium. Angiotensin II causes vasoconstriction of systemic arterioles, increases sodium reabsorption by promoting aldosterone release, decreases peritubular hydrostatic pressure, which stimulates greater reabsorption of fluid and solutes, and acts on glomerular mesangial cells, reducing glomerular filtration rate. In addition, angiotensin II stimulates the hypothalamus, which activates the thirst mechanism and promotes the release of antidiuretic hormone, causing increased distal water absorption.

Copyright © 2010 Pearson Education, Inc.

Chapter 25

sixteen.

17

18

19. 20.

21

22

23

the urinary system

Nephron Other factors that can trigger the renin-angiotensin mechanism are a fall in mean systemic arterial pressure below 80 mmHg and activation of densa cells in the macula that respond to low plasma sodium levels. (pp. 972-973) In active tubular reabsorption, substances generally move against electrical and/or chemical gradients. Substances generally move from the filtrate into the tubular cells by secondary active transport associated with Na transport and by diffusion across the basolateral membrane of the tubular cell into the interstitial space. Most of these processes involve co-transport with sodium. Passive tubular reabsorption includes diffusion, facilitated diffusion, and osmosis. Substances move along their electrochemical gradient without the use of metabolic energy. (pp. 975–976) Peritubular capillaries are porous, low-pressure capillaries that readily absorb solutes and water from tubular cells. They arise from the efferent arteriole, which drains the glomerulus. (p. 968) Tubular secretion is important for the following reasons: (a) removal of substances not already present in the filtrate; (b) remove undesired substances absorbed by passive processes; (c) rid the body of excess potassium ions; and (d) control of blood pH. Tubular secretion moves materials from the blood from the peritubular capillaries through the tubular cells or from the tubular cells into the filtrate. (p. 978) Aldosterone changes the chemistry of urine by increasing the reabsorption of sodium ions so that very little leaves the body in the urine. (p. 978) As it flows through the ascending limb of Henle's loop, the filtrate becomes hypotonic because it is impermeable to water and because sodium and chloride are actively pumped into the interstitial fluid, increasing the concentration of solutes in the interstitial liquid is lowered. tubule. The interstitial fluid at the top of the loop of Henle and in the deep parts of the medulla is hypertonic because: (1) the loop of Henle serves as a countercurrent multiplier to set up the osmotic gradient, a process that works due to the properties of the tubules and their water permeability in different areas of the tubules and ion transport to the interstitial areas; and (2) the vasa recta act as countercurrent exchangers to maintain the osmotic gradient and serve as a passive exchange mechanism, removing water from the medullary regions but leaving salts behind. The filtrate at the tip of the loop of Henle is hypertonic due to the passive diffusion of water from the descending limb into the interstitial areas. (pp. 979-981) The bladder is highly extensible. An empty bubble is collapsed and wrinkled. Expansion of the bladder to accommodate the increase in volume relies on the ability of the transitional epithelial cells lining the interior of the bladder to slide over one another, thinning the mucosa, and on the ability of the detrusor muscle to lengthen. (p. 986) When urinating, the bladder is emptied. The voiding reflex is activated when stretch receptors are activated by stretching the bladder wall. Afferent impulses are transmitted to the sacral region of the spinal cord, and efferent impulses return to the bladder via the parasympathetic pelvic splanchnic nerves, causing contraction of the detrusor muscle and relaxation of the internal sphincter. (p. 988) With age, the kidneys become smaller, the nephrons decrease in size and number, and the tubules become less efficient. By age 70, the rate of filtrate formation is half that of middle-aged adults. This slowness is believed to be the result of impaired renal blood flow caused by atherosclerosis. The bladder has shrunk to less than half the capacity of a young adult. Urinary retention and incontinence problems occur. (p. 991)

Copyright © 2010 Pearson Education, Inc.

319

320

Text and media guide to human anatomy and physiology

Critical Thinking Questions and Clinical Application 1. Diuretics remove water from the blood and excrete it in the urine. Consequently, water moves from the abdominal cavity into the bloodstream, reducing ascites. (1) Osmotic diuretics are substances that are not reabsorbed or that overwhelm the reabsorption capacity of the tubule, increase urinary osmolarity, and cause water to be drawn from the ISF into the urine. (2) Loop diuretics (Lasix) inhibit symporters in the loop of Henle by decreasing sodium chloride uptake. They reduce the normal hyperosmolarity of the medullary interstitial fluid, reducing the effects of ADH, leading to loss of NaCl and water. (3) Thiazides act on the distal convoluted tubule to inhibit water reabsorption. Your diet is salt restricted because when your blood salt levels are high it causes you to retain water instead of allowing you to get rid of it. (p. 982) 2. A lumbar spine fracture cuts off impulses to the brain so there is no voluntary control of urination and you will never feel the need to urinate again. Urine will not leak between the cavities unless the internal sphincter is damaged. Voiding is initiated in response to bladder distension by a reflex arc in the sacral region of the spinal cord, as occurs in an infant. (p. 988) 3. Cystitis is an inflammation of the bladder. Women suffer from cystitis more often than men because the female urethra is very short and its external opening is closer to the anal opening. Poor grooming habits can carry fecal bacteria into the urethra. (pp. 987-988) 4. Hattie has a kidney stone or stones in her ureter. Predisposing conditions include frequent bacterial urinary tract infections, urinary retention, high blood calcium levels, and alkaline urine. Your pain comes in waves because the waves of peristalsis travel at intervals down the ureter. Pain occurs when the walls of the ureter close over the sharp kidney stone during this peristalsis. (p. 986) 5. Female use of spermicides kills many beneficial bacteria, allowing infectious fecal bacteria to colonize the vagina. During intercourse, bacteria are transported from the vagina to the urethra, increasing the incidence of urinary tract infections in these women. (p. 988) 6. Patients with renal failure replenish phosphorus and water between dialysis sessions. Elevated phosphate levels can cause calcium to be leached from the bones. The increase in water can lead to a relatively low red blood cell count. Calcium/magnesium supplements can compensate for calcium loss from bones, but water intake must be carefully controlled to avoid plasma accumulation. (p. 984)

Recommended reading Bader, Michael. "Tissue-renin-angiotensin systems". Science and Medicine 8(3) (May/June 2002): 128–137. Borgnia, Mario, et al. "Cell and Molecular Biology of Aquaporin Water Channels". Annual Review of Biochemistry 68 (1999): 425-458. Depner, TA "'Artificial' hemodialysis versus 'natural' hemofiltration." American Journal of Kidney Diseases 52(3) (September 2008): 403-406. Hunter, Malcom. "Remedies for kidney disease". Nature 414 (6863) (November 2001): 502–503. Lee, M.Douglas et al. "The aquaporin family of water channel proteins in clinical medicine". Medicine 76(3) (May 1997): 141-156.

Copyright © 2010 Pearson Education, Inc.

Chapter 25

the urinary system

Rastogi, A. and A. Nissenson. "The future of renal replacement therapy". Advances in Chronic Kidney Disease 14(3) (2007 Jul): 249-255. Ritz, E. and C. Wanner. “Statin Use Prolongs Patient Survival After Kidney Transplantation.” Journal of the American Society of Nephrology 19(11) (November 2008): 2037–2040. Steigerwalt, S. P. "Unraveling the Causes of Hypertension and Hypokalemia." Hospital Practice 30 (July 1995): 67–68. Tajhorshid, Emad, et al. "Controlling Aquaporin Family Selectivity of Water Channels by Adjusting Global Orientation". Science 296 (April 2002): 525–530. Tanner, MJ "The Acid Test for Volume 3". Nature 382 (July 1996): 209-210. Wall, Susan M. and J.D. Klein. "Transport of H+, water and urea in the collecting duct of the inner medulla and its role in the prevention and pathogenesis of renal stone disease". Proceedings of the American Institute of Physics 1049(1) (September 2008): 101–112.

Copyright © 2010 Pearson Education, Inc.

321

26

Fluid, electrolyte and acid-base balance

Objectives Body Fluids 1. List the factors that determine the water content of the body and describe the effect of each factor. 2. Report the relative fluid volume and solute composition of the fluid compartments of the body. 3. Compare the general osmotic effects of electrolytes and non-electrolytes. 4. Describe the factors that determine fluid changes in the body. ECF water balance and osmolality 5. Identify the pathways by which water enters and leaves the body. 6. Describe the feedback mechanisms that regulate water intake and the hormonal controls of urinary water production. 7. Explain the importance of mandatory water losses. 8. Describe the possible causes and consequences of dehydration, hypotonic hydration and edema. Electrolyte balance 9. Name the entry and exit routes of electrolytes from the body.

10. Describe the importance of ionic sodium in fluid and electrolyte balance in the body and its relationship to the normal functioning of the cardiovascular system. 11. Describe the mechanisms involved in the regulation of sodium balance, blood volume and blood pressure. 12. Explain how the plasma potassium, calcium and anion balances are regulated. Acid-base balance 13. Name the main sources of acid in the body. 14. List the three main chemical buffering systems in the body and how they resist changes in pH. 15. Describe the influence of the respiratory system on the acid-base balance. 16. Describe how the kidneys regulate the levels of hydrogen and bicarbonate ions in the blood. 17. Distinguish between acidosis and alkalosis caused by respiratory and metabolic factors. Describe the importance of respiratory and renal compensation for acid-base balance. Developmental aspects of fluid, electrolyte, and acid-base balance 18. Explain why infants and the elderly are at greater risk of fluid and electrolyte imbalances than young adults.

322 Copyright © 2010 Pearson Education, Inc.

Chapter 26

Fluid, electrolyte and acid-base balance

Suggested Lesson Plan I. Body Fluids (pp. 996-998; Figures 26.1-26.3) A. Body Water Content (p. 996) 1. Total body water content is a function of age, body mass and body weight. a. Because of their low body fat and bone mass, babies are 73% water. B. The body water content of men is about 60%, but since women have relatively more body fat and less skeletal muscle than men, their content is about 50%. 2. Body water decreases over the course of life and reaches around 45% of total body mass in old age. B. Fluid Compartments (p. 996; Fig. 26.1) 1. There are two main fluid compartments in the body: The intracellular compartment contains just under two-thirds of the volume; the remaining third is distributed in the extracellular fluid. 2. There are two subcompartments of extracellular fluid: blood plasma and interstitial fluid. C. Composition of Body Fluids (pp. 996-998) 1. Non-electrolytes include most organic molecules, do not dissociate in water, and have no net electrical charge. 2. Electrolytes dissociate into ions in water and include inorganic salts, acids and bases and some proteins. 3. Electrolytes have greater osmotic power because they dissociate in water and contribute at least two particles to the solution. 4. The main cation in extracellular fluids is sodium and the main anion is chloride; in the intracellular fluid, the main cation is potassium and the main anion is phosphate. 5. Electrolytes are the most abundant solutes in body fluids, but proteins and some non-electrolytes make up 60-97% of the solutes. D. Movement of liquids between compartments (p. 998; Figs. 26.2 and 26.3) 1. Anything that changes the concentration of solutes in a compartment results in net fluxes of water. 2. Substances have to pass through both the plasma and the interstitial fluid to reach the intracellular fluid, and the exchange between these compartments takes place almost continuously, resulting in compensatory shifts from one compartment to another. 3. Virtually protein-free plasma is pressed out of the blood by hydrostatic pressure and almost completely resorbed by plasma proteins by colloid osmotic (oncotic) pressure. 4. Water movement between the interstitial fluid and the intracellular fluid involves a substantial bidirectional osmotic flow that is equal in both directions. 5. Ion fluxes between the interstitial and intracellular compartments are restricted; but the movement of nutrients, respiratory gases, and waste is generally unidirectional.

II. ECF Fluid Balance and Osmolality (pp. 998-1002; Figs. 26.4-26.7) A. In order for the body to remain adequately hydrated, water intake must equal water output (pp. 998-999).

Copyright © 2010 Pearson Education, Inc.

323

324

Text and media guide to human anatomy and physiology

B.

C.

D.

MI.

1. Most water enters the body through fluid and food intake, but is also produced through cellular metabolism. 2. Water production occurs through evaporative loss from the lungs and skin (imperceptible loss of water), sweating, defecation, and urination. Regulation of Water Intake (pp. 999-1000; Figs. 26.4-26.5) 1. The mechanism of thirst is triggered by a decrease in plasma osmolarity, which leads to dry mouth and excites the hypothalamic thirst center. 2. Thirst is quenched as the oral mucosa is hydrated and continues with expansion of the stomach and intestines, resulting in inhibition of the hypothalamic thirst center. Adjusting the water outlet (Page 1000; Fig. 26.4) 1. It is necessary to drink, because there is an inevitable loss of water from imperceptible water loss. 2. In addition to the obligatory water losses, the solute concentration and urine volume depend on fluid intake. Influence of ADH (pp. 1000-1001; Fig. 26.6) 1. The amount of water absorbed in the renal collecting ducts is proportional to the release of ADH. a. When ADH levels are low, most of the water in the collecting ducts is not reabsorbed, resulting in large volumes of dilute urine. B. When ADH levels are high, filtered water is reabsorbed, resulting in less concentrated urine. 2. The hypothalamus promotes or inhibits ADH secretion in response to changes in the concentration of solutes in the extracellular fluid, major changes in blood volume or pressure, or vascular baroreceptors. Fluid Balance Disorders (pp. 1001-1002; Fig. 26.7) 1. Dehydration occurs when water production exceeds water intake and can result in weight loss, fever, mental confusion, or hypovolemic shock. 2. Hypotonic fluid intake is due to renal failure, that is, excessive water intake too quickly. 3. Edema is fluid accumulation in the interstitial space that can affect tissue function.

3. Electrolyte Balance (pp. 1002-1008; Fig. 26.8-26.10; Tab. 26.1) A. The central role of sodium in water and electrolyte balance (pp. 1002-1004; Tab. 26.1) 1. Sodium is the most important cation im regulating the fluid and electrolyte balance in the body due to its abundance and osmotic pressure. 2. Since all body fluids are in chemical equilibrium, any change in sodium level causes a compensatory change in water level, which increases plasma volume, blood pressure, and intracellular and interstitial affected liquid volumes. B. Regulation of sodium balance (pp. 1004-1006; Figs. 26.8-26.10) 1. When aldosterone secretion is high, most of the filtered sodium is reabsorbed in the distal convoluted tubule and collecting duct. 2. The major trigger for aldosterone release is the renin-angiotensin mechanism, which is triggered in response to sympathetic stimulation, decreased filtratosmolarity, or decreased blood pressure. a. Angiotensin II, produced by the renin-angiotensin mechanism, causes the adrenal cortex to release aldosterone and also directly activates the kidneys. Copyright © 2010 Pearson Education, Inc.

Chapter 26

Fluid, electrolyte and acid-base balance

Tubules to increase Na+ retention as part of a mechanism that regulates systemic arterial pressure. 3. Cardiovascular baroreceptors control blood volume so blood pressure remains stable. 4. Atrial natriuretic peptide lowers blood pressure and blood volume by inhibiting the release of ADH, renin and aldosterone and directly induces vasodilation. 5. Estrogens are chemically similar to aldosterone and increase salt reabsorption through the renal tubules. 6. Glucocorticoids increase tubular sodium reabsorption but increase glomerular filtration. C. Regulation of Potassium Balance (pp. 1006-1007) 1. Potassium is essential for maintaining the membrane potential of neurons and muscle cells and is a buffer that balances changes in hydrogen ions inside or outside the body. 2. Potassium balance is mainly regulated by renal mechanisms that control the amount of potassium excreted in the filtrate. 3. The level of potassium in the blood plasma is the most important factor in the regulation of potassium secretion. 4. Aldosterone affects potassium secretion since potassium secretion increases concomitantly with increased sodium reabsorption. D. Regulation of Calcium and Phosphate Balance (p. 1008) 1. Calcium ion levels are tightly regulated by parathyroid hormone and calcitonin; about 98% is resorbed. a. Parathyroid hormone is released when blood calcium levels fall and it reaches the bones, small intestine and kidneys. B. Calcitonin is a parathyroid hormone antagonist and is released when calcium builds up in the blood and reaches the bone. E. Regulation of Anions (p. 1008) 1. Chloride is the main anion that is reabsorbed with sodium and helps maintain the osmotic pressure of the blood.

4. Acid-base balance (p. 1008-1015; Fig. 26.11-26.14; Table 26.2) A. Due to the abundance of hydrogen bonds in functional body proteins, these are strongly influenced by the concentration of hydrogen ions ( p. 1008-1009) . 1. When arterial blood pH rises above 7.45, the body is in alkalosis; When arterial pH drops below 7.35, the body is in physiological acidosis. 2. Most hydrogen ions are formed as by-products of metabolism, although they can also enter the body through food intake. B. Chemical Buffering Systems (pp. 1009–1010; Figure 26.11) 1. A chemical buffer is a system of one or two molecules that resists pH changes by binding H when the pH falls or releasing H when the pH falls pH falls. Fall Rise 2. The bicarbonate buffer system is the main buffer of the extracellular fluid and is made up of carbonic acid and its salt, sodium bicarbonate. a. When a strong acid is added to the solution, the carbonic acid remains largely unchanged, but the bicarbonate ions from the salt combine with the excess H and form more carbonic acid.

Copyright © 2010 Pearson Education, Inc.

325

326

Text and Media Guide for Teachers of Human Anatomy and Physiology b. When a strong base is added to the solution, the sodium bicarbonate remains relatively unchanged, but the carbonic acid continues to dissociate, releasing more H2 to scavenge the excess hydroxide. C. The bicarbonate concentration in the extracellular fluid is tightly regulated by the kidneys and the bicarbonate concentrations in the plasma are controlled by the respiratory system. 3. The phosphate buffering system acts in urine and intracellular fluid similarly to the bicarbonate buffering system: sodium dihydrogen phosphate is its weak acid and monohydrogen phosphate is its weak base. 4. The buffering system of proteins consists of organic acids containing carboxyl groups that dissociate to release H when pH begins to rise or bind excess H when pH falls. C. Respiratory regulation of H (pp. 1010-1011) 1. Carbon dioxide from cellular metabolism enters red blood cells and is converted to bicarbonate ions for transport in plasma. 2. When hypercapnia occurs, blood pH drops, activating the spinal respiratory centers, resulting in increased respiratory rate and depth, and increased CO2 release from the lungs. 3. When the blood pH rises, the respiratory center is lowered, which allows CO2 to accumulate in the blood, thereby lowering the pH. D. Renal mechanisms of acid-base balance (pp. 1011-1014; Figs. 26.12-26.14) 1. Only the kidneys can remove acids produced by cellular metabolism from the body while regulating blood levels of alkaline substances and renew the energy of the body . chemical buffering components of metabolism. a. Bicarbonate ions can be retained from the filtrate upon depletion, and their reabsorption depends on H2 secretion. B. Type A intercalated cells of renal tubules can synthesize new bicarbonate ions while excreting more hydrogen ions. C. Ammonium ions are weak acids that are excreted and lost in the urine, replenishing the blood's alkaline reserve. i.e. When the body is in alkalosis, intercalated type B cells excrete bicarbonate and reclaim hydrogen ions. E. Acid-base balance abnormalities (pp. 1014-1015; Table 26.2) 1. Respiratory acidosis is characterized by a drop in blood pH and a rise in PCO2, which is due to shallow breathing or some respiratory diseases can be. 2. Respiratory alkalosis occurs when carbon dioxide is removed from the body faster than it is produced, e.g. B. during hyperventilation. 3. Metabolic acidosis is characterized by low blood pH and bicarbonate levels due to excessive loss of bicarbonate ions or excessive alcohol intake. 4. Metabolic alkalosis is indicated by elevated blood pH and bicarbonate levels and is the result of vomiting or excessive intake of bases. 5. Respiratory rate and depth increase during metabolic acidosis and decrease during metabolic alkalosis. 6. With renal compensation for respiratory acidosis, the concentrations of PCO2 and bicarbonate ions in the blood are increased; In respiratory alkalosis, blood pH is high but PCO2 is low.

Copyright © 2010 Pearson Education, Inc.

Chapter 26

Fluid, electrolyte and acid-base balance

V. Developmental problems of fluid, electrolytes, and acid-base balance (p. 1015) A. An embryo and young fetus are more than 90% water, but as solids accumulate, the percentage drops to about 90%%70 -80% at birth (p. 1015). B. The distribution of body water begins to change at 2 months of age and adopts the adult distribution by the time the child is 2 years old (p. 1015). C. Gender differences in body water content occur during puberty as males develop more skeletal muscle (p. 1015). D. During childhood, problems with fluid, electrolyte, and acid-base balance due to widespread changes in PCO2 (p. 1015) are common. E. With aging, the loss of body water occurs mainly in the intracellular compartment, due to decreased muscle mass and increased adipose tissue (p. 1015). F. Increased insensitivity to thirst signals makes older people vulnerable to dehydration and electrolyte or acid-base imbalances (p. 1015).

Cross-references For more information on the topics discussed in Chapter 26, see the chapters listed below. 1st 2nd 3rd 4th

5. 6. 7. 8. 9.

Chapter 2: Ions; Water; Acid-Base Reactions and pH Chapter 3: Sodium-Potassium Pump; membrane transport (osmosis, diffusion) Chapter 12: Hypothalamus Chapter 16: ADH (water conservation); diabetes (mellitus, insipidus); aldosterone (sodium preservation); atrial natriuretic factor; estrogens; glucocorticoids; parathyroid hormone/calcitonin Chapter 17: Plasma Chapter 19: Baroreceptors; Capillary Exchange Chapter 22: Carbon Dioxide and Bicarbonate; Hemoglobin and pH Control Chapter 24: Ketone Bodies and Metabolism Chapter 25: ADH (Water Conservation); aldosterone (sodium preservation); atrial natriuretic factor; control of renal blood flow; glomerular filtration; glomerulonephritis; juxtaglomerular apparatus; renin-angiotensin mechanism; potassium reabsorption; H and HCO3 and the kidney

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. PhysioEx™ 8.0 Exercise 47: Acid-Base Balance: Computer Simulation 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. PhysioEx™ 8.0 Exercise 47: Acid-Base Balance: Computer Simulation

Teaching Tips 1. Clearly define the boundaries of each fluid compartment and emphasize the dynamic nature of fluid movement in the body: the sub-fluid compartments are all "connected" and it is membrane selectivity that creates the different chemical environments.

Copyright © 2010 Pearson Education, Inc.

327

328

Text and Media Human Anatomy and Physiology Teacher Guide 2. Assign students a review of osmosis and diffusion. A thorough understanding of solute and solvent movement is critical to understanding liquid-electrolyte equilibrium. 3. Emphasize the different solute compositions of the intracellular and extracellular compartments. Remind students of the physiology of the action potential as an example of the importance of maintaining cell boundaries (hence the relative composition of fluid compartments). 4. Emphasize that water always moves with solutes whenever possible. Water cannot be actively transported, so balance is achieved by controlling solute movement and water permeability. 5. Remind the class about how nerve, kidney, and hormonal mechanisms control blood pressure. All of these control systems are highly integrated, and this is an opportunity to illustrate the cooperative nature of the body's systems in maintaining homeostasis. 6. Emphasize the importance of acid-base balance and intracellular potassium levels, especially in excitable cells. Also point out that potassium is the most important ion in intracellular fluid and is therefore the primary regulator of water balance in the cell. As an interesting point, mention the consequences of too much or too little potassium. 7. Emphasize the importance of acidity or basicity in all chemical reactions. 8. Begin the discussion of acid-base balance by mentioning that the respiratory and renal systems are powerful pH control mechanisms. 9. Emphasize the difference between using strong and weak acid-base combinations as buffer systems. Connecting the two makes it easier for students to see the need for the latter. 10. Distinguish clearly between metabolic and respiratory acids and bases.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Demonstrate the principles of osmosis and diffusion to remind students of these processes. 3. Perform a simple titration to show how stronger acids and bases can be neutralized by weaker acids and bases. 4. To help students visualize how solute imbalances affect cells, get some dialysis tubing and create "cells" by filling them with saline and tying off the ends. After weighing, immerse the "cells" in hyper- and hypotonic solutions for some time, and then weigh them again.

Critical Thinking/Discussion Points 1. Discuss the effects of intravenous therapy on fluid and electrolyte balance in the body; differentiate between the infant or toddler and the adult. 2. Explain why sodium bicarbonate is used intravenously for cardiac arrest or circulatory shock. 3. Discuss the effects of alcoholism on acid-base balance. 4. Study the effects of long-term use of antacids on acid-base balance.

Library Research Topics 1. Investigate the rationale for measuring arterial blood gas levels to determine acid-base balance. Copyright © 2010 Pearson Education, Inc.

Chapter 26

Fluid, electrolyte and acid-base balance

2. Examine the reasons and effects of IV therapy in heart attack, surgery, chemotherapy, etc. 3. Examine the functions of the most common electrolytes such as Na, Mg, Ca, etc. in the body.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all of the chapter-specific online media resources for Chapter 26 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 26.1 Body Fluids (pages 996-998) Section 26.2 ECF Fluid Balance and Osmolality (pages 998-1002) Physiology Interactive 10-Systems Game: Fluids, Electrolytes and Acid-Base Balance: Introduction to Body Fluids Physiology Interactive ® 10-System Suite: Water Activity Homeostasis: Mechanisms and Consequences of ADH Release Section 26.3 Electrolyte Balance (pp. 1002-1008) MP3 Tutor Session: Regulation of Blood Volume and Blood Pressure Interactive Physiology® 10-System Suite: Electrolyte Homeostasis Study Case Study: Fluids and Electrolytes Section 26.4 Acid -Base Balance (pp. 1008-1015) 10-System Interactive Game Physiology®: Acid/Base Homeostasis PhysioEx™ 8.0: Acid/Base Balance Case Study: Kidney Failure Section 26.5 Developmental Aspects of Fluid, Electrolytes, and Acid-Base Balance ( p. 1015) Chapter Summary Crossword 26.1 Web links Tests of l Chapter Art Labeling Quiz Quiz and combination -Multiple Choice Quiz True False Quiz Chapter Quiz Practice Study Tools Histology Atlas myeBook Flashcards Glossary Copyright © 2010 Pearson Education, Inc. All rights reserved.

329

330

Text and media guide to human anatomy and physiology

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1. Homeostasis (FHS; 60 min). Six part video series. Each video lasts 10 minutes. Presenting a comprehensive definition of homeostasis, the show uses computer animation to illustrate how the body copes with stress and changing conditions. 2. Homeostasis (FHS; 20 min, 1995). To understand homeostasis in a natural environment, this program examines what happens to the body during a marathon.

Software 1. Interactive suite of 10 Physiology® Systems: Fluids and Electrolytes (BC; Win/Mac). It focuses on the physiological processes involved in maintaining homeostasis. It includes animated raw and cell-level tutorials and quizzes to help students test their knowledge. 2. Exercise and Fluid Balance (IM; Windows). This CD-ROM explains how solutions, solutes and the semipermeable membrane interact in diffusion and osmosis, considering osmotic and hydrostatic pressure, filtration and the effects of plasma proteins. 3. Fluids and Electrolytes CD-ROM (IM; Windows). Allows users to examine and analyze fluids and electrolytes at any pace. Includes case studies, self-assessment tools and over 150 animations.

Material to improve the lesson Thumbnails of all illustrations in Chapter 26 can be found in Appendix B.

Instructor Transparency Index/Resource DVD Figure 26.1 Figure 26.2 Figure 26.3 Figure Figure Figure Figure Figure Figure

26,4 26,5 26,6 26,7 26,8 26,9 26,10

The main fluid compartments of the body. Electrolytic composition of blood plasma, interstitial fluid and intracellular fluid. Exchange of gases, nutrients, water and waste between the three fluid compartments of the body. Main sources of water entry and exit. The mechanism of thirst to regulate water intake. Mechanisms and consequences of ADH release. changes in the water balance. Mechanisms and consequences of aldosterone release. Mechanisms and consequences of the release of ANP. Mechanisms that regulate sodium and water balance help maintain blood pressure homeostasis.

Copyright © 2010 Pearson Education, Inc.

Chapter 26 Figure 26.11 Figure 26.12 Figure 26.13 Figure 26.14 Table 26.1 Table 26.2 A Closer Look Making Connections

Fluid, electrolyte and acid-base balance

Dissociation of strong and weak acids in water. Reabsorption of filtered HCO3 is coupled with H secretion. New HCO3 is generated by buffering of secreted H by HPO42 (monohydrogen phosphate). The new HCO3 is created by the glutamine metabolism and the release of NH4. Causes and consequences of electrolyte imbalances Causes and consequences of acid-base imbalances Research: Using blood values ​​to determine the cause of acidosis or alkalosis Homeostatic connections between the urinary system and other body systems

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 14. Body fluid compartments include the intracellular fluid compartment, located within cells with a fluid volume of approximately 25 liters, and the extracellular fluid compartment (plasma and interstitial fluid), located outside each cell and with a fluid volume of approximately 25 liters has 15 liters. . (p. 996) 15. A 10-15% decrease in plasma volume and/or a 2-3% increase in plasma osmolarity results in dry mouth and stimulates the hypothalamic thirst or drinking center. Hypothalamic stimulation occurs because the osmoreceptors in the thirst center become irritable and depolarize when water, driven by the hypertonic ECF, leaves them by osmosis. Taken together, these events produce a subjective feeling of thirst. Thirst quenching begins when the mucous membranes of the mouth and throat become moist and continues as stretch receptors in the stomach and intestines are activated, providing feedback signals that inhibit the hypothalamic thirst center. (p. 999) 16. It is important to control the osmolarity of the extracellular fluid (ECF) since the ECF determines the ICF volume and underlies the control of fluid balance in the body. The ECF is maintained by both thirst and antidiuretic hormone (ADH). An increase in plasma osmolarity triggers thirst and the release of ADH; a drop in plasma osmolarity inhibits thirst and ADH. (pp. 999-1000) 17. Sodium is essential for fluid and electrolyte balance and homeostasis of all body systems as it is the major extracellular ion. Although the body's sodium content can change, its concentration in the extracellular fluid remains stable due to immediate adjustments in water volume. The regulation of sodium-water balance is inextricably linked to blood pressure and involves a variety of neural and hormonal controls: (1) aldosterone: increases reabsorption of sodium from the filtrate; the water follows passively by osmosis, increasing blood volume (and pressure). The renin-angiotensin mechanism is an important control of aldosterone release; The juxtaglomerular apparatus responds to: (a) decreased stretch (due to decreased blood pressure), (b) decreased filtratosmolarity, or (c) stimulation of the sympathetic nervous system, ultimately leading to the release of aldosterone from the adrenal cortex. (2) ADH: Osmoreceptors in the hypothalamus sense the concentration of solutes in the ECF: increases in sodium levels stimulate ADH release, resulting in increased kidney retention of water (and increased blood pressure). (3) Atrial Natriuretic Peptide: Released by cells in the atria during hypertensive situations and has a potent effect

Copyright © 2010 Pearson Education, Inc.

331

332

Text and media guide to human anatomy and physiology

18

19

20

21

diuretic and natriuretic (sodium excretion) effects; the kidneys don't reabsorb as much sodium (hence water) and blood pressure drops. (pp. 1002-1007) A physiological buffer system is used to regulate the acid-base balance of the respiratory system. The drop in pH due to the increased concentration of hydrogen ions or PCO2 in the plasma stimulates (directly or indirectly) the respiratory center to stimulate deeper and faster breathing. When pH begins to drop, the respiratory center becomes inhibited. (pp. 1010-1011) Acid-base chemical buffers prevent sharp changes in H+ concentration by binding hydrogen ions to body fluids as the pH falls and releasing them as the pH rises. (p. 1009) (a) The rate of H secretion rises and falls directly with the CO2 content in the ECF. The higher the CO2 content in peritubular capillary blood, the faster the rate of H secretion. (b) Intercalated type A cells actively secrete H through an H-ATPase pump and through a K-H antiporter. The excreted H combines with HPO42 to form H2PO4, which then passes into the urine. c) The dissociation of carbonic acid in the tubular cells releases HCO3 and HCO3. HCO3 is shunted into the peritubular capillary blood. The rate of bicarbonate reabsorption depends on the rate of H secretion or excretion in the filtrate. (p. 1012) Factors that put newborns at risk for acid-base imbalances include a very low residual volume of the infant's lungs, high fluid intake and output, relatively high metabolic rate, low perceptual water loss, and kidneys Inefficiency. (Page 1015)

Critical Thinking Questions and Clinical Applications 1. This patient has diabetes insipidus caused by insufficient production of ADH by the hypothalamus. The surgery to remove the brain tumor damaged the hypothalamus, or hypothalamic-pituitary tract, which leads to the posterior pituitary gland. Due to the lack of ADH, the collecting ducts and possibly the convoluted portion of the distal convoluted tubule do not take up water from the glomerular filtrate. The result is the large amount of very dilute urine passed by this man and the intense thirst he feels. (pp. 1000-1001) 2. Task 1: pH 7.63, PCO2 19 mm Hg, HCO3 19.5 m eq/L a. pH is high = alkalosis. B. PCO2 is low and is the cause of alkalosis. C. HCO3 is also low = compensation. It is a respiratory alkalosis, possibly due to hyperventilation, compensated by metabolic acidosis. Task 2: pH = 7.22, PCO2 30 mm Hg, HCO3 12.0 mEq/L a. The pH is below normal = acidosis. B. The PCO2 is low, so it doesn't cause the acidosis, but it compensates for it. C. The HCO3 is too low and is the cause of the acidosis. This is metabolic acidosis. Possible causes include ingestion of too much acid (too much alcohol), excessive bicarbonate loss (diarrhea), lactic acid buildup during exercise, shock or ketosis that occurs with diabetic flare-ups, or starvation. (pp. 1008-1013) 3. Emphysema impairs gas exchange or pulmonary ventilation, leading to carbon dioxide retention and respiratory acidosis. Heart failure causes oxygenation problems, edema, and metabolic acidosis due to increased lactic acid. (pp. 1010-1011) Copyright © 2010 Pearson Education, Inc.

Chapter 26

Fluid, electrolyte and acid-base balance

4. The patient has a normal sodium ion concentration; The CO2 is a bit low as is the Cl. The potassium ion concentration is so abnormal that the patient has a medical emergency. The greatest danger is (c) cardiac arrhythmias and cardiac arrest. (p. 1003) 5. Candace's right kidney is smaller due to decreased blood flow due to narrowing of the right renal artery. The reduced blood flow from the right kidney decreases the kidney's glomerular filtration rate, which responds by telling the body to increase blood pressure in order to increase blood flow to the kidney. You would expect your potassium levels to be low and your sodium, aldosterone, angiotensin II, and renin levels to be high. (pp. 972, 1000–1004, 1007)

Recommended reading Alpern, R. J. and F. A. Freisig. "Kidney acid-base transport". For kidney diseases. 6th ed. Baltimore: Lippincott Williams & Wilkins, 1996. Gamble, J.L., Jr. "Approaching acid-base relationships in the body as a whole." Perspectives in Biological Medicine 39 (1996): 593. Giotta, N. and A .Marino. "Calcimimetics, calcium set point and calcium balance". Nephrology Dialysis Transplantation 23(12) (December 2008): 4083-4084. Halperin, M.L. and M. Goldstein. Fluids, electrolytes, and acid-base physiology: a problem-based approach. 3rd Ed. Philadelphia: W.B. Saunders Co., 1998. Harvey, T.C. "Addison's disease and potassium regulation: the role of insulin and aldosterone." Medical Hypotheses 69(5) (April 2007): 1120–1126. Hayes, Denise D. "When Potassium Takes Dangerous Detours." Nursing 37(11) (November 2007): 56. Heintz, UE, and MM Horne. Pocket guide to fluid, electrolyte and acid-base balance. 5th ed. S t. Luis: C.B. Mosby Co., 2004. Hunt, Curtiss D. and L.K. Johnson. "Calcium requirements: new estimates for males and females using cross-sectional statistical analyzes of calcium balance data from metabolic studies". The American Journal of Clinical Nutrition 86(4) (October 2007): 1054-1063. Laski, Melvin E., and S. Sabatini. "Metabolic alkalosis, bed and bench". Seminars in Nephrology 26(6) (November 2006): 404–421. Shirreffs, Susan M., et al. "Rehydration after exercise in the heat: a comparison of 4 commonly used beverages". International Journal of Sports Nutrition and Exercise Metabolism 17(3) (June 2007): 244-258. Simonson, MS "Endothelins: Multifunctional Kidney Peptides." Physiological Reviews 73 (January 1993): 375. Vestergaard, Peter. "Skeletal Effects of Systemic and Topical Corticosteroids". Current Drug Safety 3(3) (September 2008): 190-193. Wakabayashi, S., et al. "Molecular physiology of vertebrate Na/H exchangers". Physiological Reviews 77 (1997):51.

Copyright © 2010 Pearson Education, Inc.

333

27

reproductive system

Learning Outcomes Male Reproductive System Anatomy 1. Describe the structure and function of the testicles and explain the importance of their position in the scrotum. 2. Describe the structure of the penis and indicate its role in the reproductive process. 3. Describe the location, structure and function of the male accessory reproductive organs. 4. Discuss the sources and functions of the seed. Physiology of the male reproductive system 5. Describe the phases of the male sexual response. 6. Define meiosis. Compare and contrast with mitosis. 7. Describe the events of spermatogenesis. 8. Discuss the hormonal regulation of testicular function and the physiological effect of testosterone on male reproductive anatomy. Anatomy of the female reproductive system 9. Describe the location, structure and function of the ovaries. 10. Describe the location, structure and function of each organ in the female reproductive system.

11. Describe the anatomy of the female external genitalia. 12. Discuss the structure and function of the mammary glands. Physiology of the female reproductive system 13. Describe the process of oogenesis and compare it with spermatogenesis. 14. Describe the phases of the ovarian cycle and relate them to the events of oogenesis. 15. Describe the regulation of the ovarian and uterine cycles. 16. Discuss the physiological effects of estrogens and progesterone. 17. Describe the phases of the female sexual response. Sexually Transmitted Infections 18. Describe the infectious agents and modes of transmission for gonorrhea, syphilis, chlamydia, trichomoniasis, genital warts and genital herpes. Aspects of the development of the reproductive system 19. Discuss the genetic determination of sex and the prenatal development of male and female structures. 20. Be aware of the significant events of puberty and menopause.

334 Copyright © 2010 Pearson Education, Inc.

Chapter 27

reproductive system

SUGGESTED LESSON OUTLINE I. Anatomy of the Male Reproductive System (pp. 1025-1031; Figs. 27.1-27.4) A. The scrotum is a dermal sac and superficial fascia lying outside the abdominal-pelvic cavity at the base of the penis and the testicles (pp. 1025-1026; figs. 27.1-27.2). 1. Provides an environment that is 3° below core body temperature. 2. Responds to temperature changes. B. The testicles are the main male reproductive organ and produce sperm and testosterone (pp. 1026-1028; Figs. 27.1-27.3). 1. The testicles are divided into lobes with seminiferous tubules inside, where sperm are produced. 2. Interstitial cells reside in the connective tissue that surrounds the seminiferous tubules and produce testosterone. C. The penis is the copulatory organ designed to carry sperm into the female reproductive system (p. 1028; Figs. 27.1, 27.4). 1. The penis consists of an attached root and a free rod or body ending in the glans. 2. The foreskin or foreskin covers the penis and can be pushed back to form a cuff around the glans. 3. Inside the penis are the corpus spongiosum and corpus cavernosum, two cavernous bodies. D. The Male Duct System (pp. 1028-1030; Figs. 27.1, 27.4) 1. The epididymis consists of a tightly coiled tube that provides a site for immature sperm to mature and be expelled during ejaculation. 2. The vas deferens or vas deferens transports sperm from the storage sites in the epididymis through the inguinal canal through the bladder and into the ejaculatory duct. 3. The urethra is the final section of the male duct system and transports urine and semen (not simultaneously) to the outside. E. Adrenal Glands (pp. 1030-1031; Figs. 27.1, 27.4) 1. Seminal vesicles are located on the posterior wall of the bladder and their alkaline secretion accounts for 60% of the volume of semen, consisting of fructose, ascorbic acid, a coagulant, enzyme (vesiculase) and prostaglandins. 2. The prostate is responsible for producing a milky, slightly acidic fluid containing citrate, various enzymes and prostate-specific antigen, which makes up about a third of semen. 3. The bulbourethral or Cowper's glands produce a thick, clear mucus prior to ejaculation that neutralizes any acidic urine in the urethra. F. Semen is a milky white, somewhat sticky mixture of sperm and accessory gland secretions that provides a means of transport for sperm (p. 1031).

II. Physiology of the Male Reproductive System (pp. 1031-1040; Figs. 27.5-27.9; Table 27.1) A. Male Sexual Response (pp. 1031-1032) Penile bloody corpora cavernosa elicited during sexual arousal. 2. Ejaculation is the ejection of semen from the male duct system by the sympathetic nervous system. Copyright © 2010 Pearson Education, Inc.

335

336

Text and media Teacher's manual of human anatomy and physiology B. Spermatogenesis is the sequence of events in the seminiferous tubules that produce male gametes (sperm or spermatozoa) (pp. 1032-1038; Figs. 27.5-27.8). 1. Meiosis consists of two consecutive nuclear divisions and the production of four daughter cells with half the cell number of a normal body cell. a. Meiosis I reduces the number of chromosomes in a cell from 46 to 23 by separating the homologous chromosomes in different cells. B. Meiosis II resembles mitosis in all respects except that the chromatids divide into four cells. 2. Summary of events in the seminiferous tubules a. Spermatogenesis begins when spermatogonia divide to produce type A daughter cells that maintain the stem cell lineage and type B daughter cells that are pushed into the lumen to become primary spermatocytes and eventually sperm. B. Each primary spermatocyte undergoes meiosis I to produce two secondary spermatocytes, which then undergo meiosis II to form spermatids. C. Spermogenesis is a toning process that removes excess cytoplasm from the spermatid and forms a tail, resulting in a sperm with a head, midsection and tail. i.e. Sustentacular cells, or Sertoli cells, form a blood-testis barrier that prevents membrane-bound antigens from entering the bloodstream. C. Hormonal regulation of male reproductive function (pp. 1038-1040; Fig. 27.9; Box 27.1) 1. The cerebro-testicular axis refers to the relationship and interaction between the hypothalamus, anterior pituitary and testes. a. The hypothalamus releases gonadotropin-releasing hormone (GnRH), which controls the release of the anterior pituitary hormones, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in males. B. FSH indirectly stimulates spermatogenesis. C. LH, also called interstitial cell-stimulating hormone (ICSH), stimulates interstitial cells to produce testosterone. i.e. Locally, testosterone acts as the final trigger for spermatogenesis. Y. Testosterone inhibits the hypothalamic release of GnRH and acts directly on the anterior pituitary gland to inhibit gonadotropin release. F. Inhibin is produced and released by host cells when sperm count is high. 2. Mechanism and Effects of Testosterone Activity a. Testosterone is synthesized from cholesterol and exerts its effects by activating specific genes for transcription. B. Testosterone targets accessory organs (ducts, glands and penis) causing them to grow and assume adult size and function. C. Testosterone induces male secondary sex characteristics: pubic, axillary, and facial hair, a deeper voice, thickening of the skin and increased oil production, and an increase in the size and mass of bones and skeletal muscle.

3. Anatomy of the Female Reproductive System (pp. 1040-1049, Figs. 27.10-27.16) A. The ovaries are the main reproductive organs in women (pp. 1040-1042; Figs. 27.10-27.12).

Copyright © 2010 Pearson Education, Inc.

Chapter 27

reproductive system

1. The ovaries produce the female gametes (ova or ova) and sex hormones (estrogen and progesterone). 2. The paired ovaries lie on each side of the uterus and are held in place by different ligaments. 3. Sac-like structures called ovarian follicles consist of an immature egg called an oocyte surrounded by one or more layers of different cells. 4. Follicles at different stages are distinguished by their structure as primordial follicles, primary follicles, secondary follicles, and Graafian or vesicular follicles. 5. Ovulation occurs every month in adult women when one of the maturing follicles ejects its egg from the ovary. 6. The ruptured follicle turns into a glandular structure called the corpus luteum, which eventually degenerates. B. The Female Duct System (pp. 1042-1046; Figs. 27.10, 27.12-27.13) 1. The oviducts or fallopian tubes form the beginning of the female duct system, receiving the ovulated egg and providing it with a site for fertilization to take place . 2. The uterus is a hollow, thick-walled, muscular organ designed to receive, hold, and nourish a fertilized egg. a. The uterus is supported by the mesometrium, lateral cervical ligaments, uterosacral ligaments, and round ligaments. B. The wall of the uterus consists of three layers: the perimetrium, the myometrium, and the endometrium. 3. The vagina provides a passageway for birth and menstrual blood and also receives the penis and semen during intercourse. C. The external genitalia, also called the vulva or pubic bone, includes the mount of Venus, labia, clitoris, and structures associated with the vestibule (pp. 1046-1047; Figs. 27.10, 27.14). D. Mammary glands are present in both sexes but generally function only in females to produce milk to nourish a newborn (pp. 1047-1049; Figs. 27.15-27.16). 1. Mammary glands are modified sweat glands that are actually part of the skin system. 2. Breast cancer usually arises from the epithelial cells in the ducts and develops into a lump where the cells eventually metastasize.

4. Physiology of the female reproductive system (pp. 1049-1058; Figs. 27.17-27.20; Table 27.1) A. Oogenesis is the production of female gametes called ovules, ova, or ova (p. 1049; Fig. 27.17). 1. A woman's total supply of oocytes is determined at birth and the time at which she releases them extends from puberty to menopause. 2. In the fetal period, oogonia rapidly multiply by mitosis, become primordial follicles, and then primary follicles, initiating the first meiotic division. 3. After puberty, some oocytes are activated each month, but only one proceeds to meiosis I, which eventually produces two haploid cells, a polar body, and a secondary oocyte. 4. The secondary oocyte stops at metaphase II and if a sperm penetrates it, it will complete meiosis II and produce a second polar body and a large oocyte.

Copyright © 2010 Pearson Education, Inc.

337

338

Text and media Manual of human anatomy and physiology B. The ovarian cycle is the monthly series of events associated with the maturation of the ovum (pp. 1049-1052; Fig. 27.18). 1. The follicular phase is the period of follicle growth, which generally lasts from 1 to 14 days. 2. Ovulation occurs when the wall of the ovary ruptures and the secondary egg is expelled. 3. The luteal phase is the period of activity of the corpus luteum from the 14th to the 28th day. C. Hormonal Regulation of the Ovarian Cycle (pp. 1052-1054; Figs. 27.19; Box 27.1) 1. During childhood, the ovaries enlarge and secrete small amounts of estrogen that inhibit GnRH release until puberty, when the hypothalamus becomes active. It becomes less sensitive to estrogen and begins to rhythmically release GnRH. 2. Hormonal Interactions During the Ovarian Cycle a. On day 1 of the cycle, GnRH levels rise, stimulating further production and release of FSH and LH. B. FSH and LH stimulate the growth and maturation of the follicles and the secretion of estrogens. C. Increasing plasma estrogen levels exert a negative feedback on the anterior pituitary gland and inhibit the release of FSH and LH. i.e. Estrogen exerts positive feedback on the anterior pituitary gland, resulting in an LH surge that triggers ovulation and converts the ruptured follicle into the corpus luteum. Y. Elevated plasma levels of progesterone and estrogen exert a negative feedback on the release of LH and FSH. F. LH levels fall and luteal activity ceases; The corpus luteum degenerates, lowering estrogen and progesterone levels and the cycle begins again. D. The uterine (menstrual) cycle is a series of cyclical changes that the uterine endometrium undergoes each month in response to changes in ovarian hormone levels in the blood (pp. 1054-1056; Fig. 27.20). 1. The menstrual phase usually occurs between the 1st and 5th day and is the time when the endometrium is shed from the uterus. 2. The proliferation phase (6 to 14 days) is the time when the endometrium rebuilds and becomes velvety, thick and well vascularized again. 3. The secretory phase (days 15 to 28) is the phase in which the endometrium prepares for implantation of an embryo. E. Extrauterine Effects of Estrogens and Progesterone (pp. 1056-1057; Table 27.1) 1. Elevated levels of estrogen promote oogenesis and follicular growth in the ovaries and the growth and function of female reproductive structures. 2. Estrogens also cause the epiphyses of long bones to close during pubertal growth spurts. 3. Estrogen-induced secondary sex characteristics in women include breast enlargement, increased subcutaneous fat deposition on hips and breasts, pelvic widening and lightening, pubic and armpit hair growth, and metabolic changes. 4. Progesterone works with estrogen to build and regulate the uterine cycle and promote changes in cervical mucus. F. In the female sexual response, the clitoris, vaginal mucosa, and breasts fill with blood; erect nipples; increased activity of the vestibular glands; and the final phase is the orgasm (p. 1058).

Copyright © 2010 Pearson Education, Inc.

Chapter 27

reproductive system

V. Sexually Transmitted Infections (p. 1058-1059) A. gonorrhea is caused by the bacterium Neisseria gonorrhoeae, which invades the lining of the urinary and reproductive tract (p. 1058). B. Syphilis is caused by Treponema pallidum, a bacterium that easily penetrates intact mucous membranes and broken skin and enters the lymphatics and bloodstream (p. 1058). C. Chlamydia is the most common sexually transmitted infection in the United States and is caused by the bacterium Chlamydia trachomatis (pp. 1058-1059). D. trichomoniasis is the most common curable STD among sexually active young women in the United States. This parasitic infection manifests as a greenish-yellow vaginal discharge with a strong odor (p. 1059). E. Genital warts are caused by a group of about 60 viruses known as human papillomaviruses (HPV) (p. 1059). F. genital herpes is most commonly caused by herpes simplex virus type 2, which is transmitted through infectious secretions (p. 1059).

SEEN. Developmental aspects of the reproductive system (pp. 1059-63, 1066; Figs. 27.21-27.22) A. Embryological and fetal events (pp. 1059-63; Figs. 27.21-27.22) 1. Sex is determined by the sex chromosomes at conception; Females have two X chromosomes and males have one X and one Y chromosome 2. Sexual differentiation of the reproductive system a. Both the male and female gonads begin to develop in the fifth week of pregnancy. B. During the seventh week, the gonads begin to develop into testes in males, and in the eighth week they begin to form ovaries in females. C. The external genitalia arise from the same structures in both sexes, with differentiation occurring at 8 weeks. 3. About two months before birth, the testicles begin to descend into the scrotum, taking their blood and nerve supply with them. B. Puberty is the period of life, usually between ages 10 and 15, when the reproductive organs reach adult size and become functional (p. 1063). C. Ovarian function gradually decreases with age; Menstrual cycles become more irregular and shorter until menopause, when ovulation and menstruation stop altogether (pp. 1063, 1066).

Cross-references For more information on the topics discussed in Chapter 27, see the chapters listed below. 1st 2nd 3rd 4th 5th 6th 7th

Chapter chapter chapter chapter chapter chapter chapter

3: cell division; tight transitions; organelles; microvilli 4: pseudostratified epithelium; tubuloalveolar glands 9: peristalsis (smooth muscle contraction) 10: male and female perineum; Pelvic Floor Muscles 12: Testosterone and Brain Anatomy 13: Reflex Activity 14: Sympathetic and Parasympathetic Effects

Copyright © 2010 Pearson Education, Inc.

339

340

Text and media Teacher's manual of human anatomy and physiology 8. Chapter 16: Cerebro-testis axis; prostaglandins; Testosterone; FSH and LH; Ovaries and Estrogens 9. Chapter 25: Male Urethra 10. Chapter 28: Fertilization; vaginal environment and sperm viability; passage of sperm through the female reproductive tract in preparation for fertilization; Connection of the structure of sperm and egg cells with fertilization; uterine function in reproduction; Interruption of the uterine and ovarian cycles due to pregnancy; Completion of Meiosis II 11. Chapter 29: Meiosis Related to Genetics; Importance of tetrad formation and recombination

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 42: Reproductive System Anatomy Exercise 43: Reproductive Physiology: Gametogenesis and the Female Cycles 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 42: Reproductive System Anatomy Exercise 43: Reproductive Physiology: Gametogenesis and the Female Cycles

Teaching Tips 1. Emphasize that sperm are not able to fertilize an egg immediately, but must first be activated, either naturally or artificially. 2. The duct system of the male reproductive system is difficult for most students to imagine. Use models and diagrams to visualize the three-dimensional structure. 3. Emphasize the various secretions (and their functions) in the male reproductive system. 4. Use cross-sectional and longitudinal diagrams of penile anatomy. Both sections are necessary to create the correct three-dimensional internal structure. 5. Emphasize the difference between mitosis and meiosis. Mitosis involves a single round of DNA synthesis followed by a single cytokinetic event resulting in two diploid cells. Meiosis involves a single round of DNA synthesis followed by two consecutive cytokinetic events that result in four haploid structures (four sperm in the male, or two or three polar bodies and one egg in the female). 6. Students will gain a better understanding by drawing a schematic diagram of spermatogenesis and matching it to a cross-section of a seminiferous tubule. 7. Be sure to give the reasons for the terms reduction and equatorial splitting. Students often struggle with the concept of chromatid versus chromosome and thus have difficulty with these terms. 8. Distinguish clearly between spermatogenesis and spermiogenesis. Students are often confused by similar-sounding names. 9. Emphasize that erection is a parasympathetic response and ejaculation is due to sympathetic reflex action. 10. Emphasize the importance of the blood testicular barrier in preventing immune responses against sperm antigens.

Copyright © 2010 Pearson Education, Inc.

Chapter 27

reproductive system

11. Emphasize that testosterone has both somatic and reproductive effects. 12. Mention that the term germinal epithelium has nothing to do with the formation of the ovum. 13. It is often advantageous to compare and contrast spermatogenesis and oogenesis side by side to highlight similarities and differences. 14. Emphasize that the secondary oocyte (even at first ovulation) does not complete meiosis II until it is fertilized by sperm and therefore technically should not be called an egg until fertilization has occurred. 15. Mention that the polar bodies are actually tiny nucleated haploid cells (which do not fertilize) and that the difference in size between the polar bodies and the oocyte is due to the amount of cytoplasm present. 16. Much confusion can arise in the presentation of the ovarian and menstrual cycles. Regardless of the order of presentation, emphasize that both cycles are simultaneous and both should be viewed as a continuous process, even though different events occur at different times. At the conclusion of the discussion, graph the hormone concentration versus day of the cycle and examine the function of each hormone as levels rise and fall. Be sure to include the hormone sources (follicles vs. corpus luteum) so students understand maintaining pregnancy in Chapter 28. 17. Emphasize the difference between the menstrual phase and the menstrual cycle. Students often confuse the two. 18. Explain clearly the determination of chromosome sex. Emphasize that it is the male that determines sex, since the female can only contribute one possible form of sex chromosome, but the male contributes one of two possible chromosome choices.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Use a torso model, reproductive model, and/or stuffed animal model to show the reproductive organs. 3. Post a large chart of hormone levels throughout the ovarian and menstrual cycles on the wall. 4. Project a series of 2 color slides of the cell reproduction process to refresh your memory of the sequence of events. 5. Obtain and create slides on the effects of various sexually transmitted infections. 6. Get or prepare a briefing on the different methods of birth control. 7. Use models showing the process of meiosis in spermatogenesis and oogenesis. 8. Show a diagram or slide of a mature follicle and a primordial follicle to illustrate the difference in size between the two.

Critical Thinking/Discussion Points 1. Discuss the need for mammograms and self-exams for early detection of breast cancer. 2. Emphasize the need for self-examination for testicular cancer. 3. Describe the currently available treatments for breast cancer. 4. Explore the signs and symptoms of PMS and menopause. 5. Discuss the different treatments that are available for infertility. Copyright © 2010 Pearson Education, Inc.

341

342

Text and Media Human Anatomy and Physiology Teacher Guide 6. Describe the consequences of the failure of the blood-testicular barrier. 7. Examine the possible consequences of estrogen (or other reproductive hormone) deficiency during the ovarian and menstrual cycles.

Library Research Topics 1st 2nd 3rd 4th

Research current treatments for breast cancer. Examine current treatments for prostate disease. Investigate disorders related to the menstrual cycle. Examine the different causes of infertility in men and women and how to increase fertility. 5. Find out about the latest advances in contraception. How soon will a male oral contraceptive be available? What about the five year old female contraceptive implant? 6. Research the medical community's current perspective on hormone replacement therapy and menopause.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all of the chapter-specific online media resources for Chapter 27 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 27.1 Anatomy of the male reproductive system (pp. 1025-1031) Artist Caption: Male reproductive system, sagittal view (Fig. 27.1, p. 1025) Case study: Reproductive system Section 27.2 Physiology of the male reproductive system (pp. 1031-1040) Section 27.3 Anatomy of the female Reproductive system (pp. 1040-1049) Artist Tag: Internal organs of the female reproductive system, midsagittal view (Fig. 27.10, p. 1040) Artist Tag: Structure of an ovary (Fig. 27.11, p. 1041) Section 27.4 Physiology of the female reproductive system (p 1049–58) MP3 Tutor Session: Hormonal Control of the Menstrual Cycle Memory Game: Male and Female Reproductive Organs Section 27.5 Sexually Transmitted Infections (pp. 1058–59) Case Study: Sexually Transmitted Infections Section 27.6 Developmental Aspects of the Reproductive System (pp. 1059–1063, 1066) Chapter Summary Crossword 27.1 Crossword 27.2 Links Net

Copyright © 2010 Pearson Education, Inc.

Chapter 27

reproductive system

Chapter Test Art Labeling Test Matching Test Multiple Choice Test True or False Test Chapter Practice Test Study Tools Histology Atlas myeBook flashcards glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1. A Human Life Is Born (FHS; 35 min., 1995). This program provides an in-depth look at reproduction, beginning with the fertilization of the female egg, through pregnancy and millions of cell divisions, to the birth of a fully formed individual. 2. Human Reproductive System (IM; 20 min, 2002). This DVD covers human reproductive anatomy. Describe the structures and functions of each reproductive organ and show how the male and female systems work together to create new life. 3. Human Reproductive Biology (FHS; 35 min, 1994). This program focuses on the processes that lead to normal impregnation and the physical obstacles that can prevent it. Microscopy and computer animation illustrate the processes. 4. Human Reproductive System Videotape (BC; 32 min., 1999). This video gives an overview of the human reproductive system. 5. Reproduction: Actions in the future (FHS; 26 min., 1984). From The Living Body series, this show shows the characteristics of sperm and egg cells and how each contains a partial blueprint for future offspring. The mechanism of cell division is shown through photomicrographs and the mechanisms of inheritance are carefully described. 6. The reproductive system (NIMCO; 18 min, 1998). Part of The Human Body series, this program examines the maturation of ova and sperm and explains the genetic contribution each makes to the fertilized ovum. 7. Unprotected sex and its consequences (FHS; 20 min., 1995). Identifies the most common sexually transmitted infections other than HIV and discusses their symptoms, treatment, and prevention.

Software 1. A.D.A.M.® Interactive Anatomy® 4.0 (see full list on page 9 of this manual). 2. A.D.A.M.® MediaPro (see page 9 of this manual for a complete list). Copyright © 2010 Pearson Education, Inc.

343

344

Instructor's Guide to Text and Media for Human Anatomy and Physiology 3. A.D.A.M.® Anatomy Practice (see page 87 of this guide for a complete list). 4. Practice Anatomy Lab™ 2.0: Human cadaver, anatomical models, histology, cat, fetal pig (see full list on page 9 of this manual). 5. The Ultimate Human Body, version 2.2 (see page 9 of this manual for the full list). 6. Virtual Microscope Explorer, Vol. 3: Mitosis and meiosis (CBS; Windows). This interactive multimedia CD-ROM helps students understand the detailed concepts of mitosis and meiosis using a virtual microscope. Vivid photomicrographs show the different stages of chromosomal dynamics during mitosis and meiosis.

Reading Enhancement Material Thumbnails of all figures in Chapter 27 can be found in Appendix B.

Index Instructor Slide/Resource DVD Image Image Image Image Image

27,1 27,2 27,3 27,4 27,5

Figure 27.6 Figure 27.7 Figure 27.8 Figure 27.9 Figure 27.10 Figure Figure Figure Figure Figure Figure Figure

27,11 27,12 27,13 27,14 27,15 27,16 27,17 27,18

Figure 27.19 Figure 27.20 Figure 27.21 Figure 27.22 Table 27.1 Connections

Male reproductive system, sagittal view. Relations of the testicle to the scrotum and spermatic cord. testicular structure. Male reproductive structures. Comparison of mitosis and meiosis in a mother cell with a diploid number (2n) of 4. Meiosis. spermatogenesis. Spermogenesis: Conversion of a spermatid into a functional spermatozoon. Hormonal regulation of testicular function, hypothalamic-pituitary-gonadal axis. Internal organs of the female reproductive system, mid-sagittal section. Structure of an ovary. Internal reproductive organs of a woman. The endometrium and its blood supply. The female external genitalia (vulva). Structure of the lactating mammary glands. mammograms. oogenesis events. Schematic and microscopic views of the ovarian cycle: development and fate of the ovarian follicles. Feedback interactions in the regulation of ovarian function. Correlation of anterior pituitary and ovarian hormones with structural changes in the ovary and uterus. Development of the internal reproductive organs. Development of homologous structures of the external genitalia in both sexes. Summary of the hormonal effects of gonadal estrogens, progesterone and testosterone Homeostatic interrelationships between the reproductive system and other body systems

Copyright © 2010 Pearson Education, Inc.

Chapter 27

reproductive system

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 18. In males, the urethra carries both urine and semen and thus serves the urinary and reproductive systems; in women, the two systems are structurally and functionally separate. (p. 1030) 19. The regions of the sperm are the head: the genetic region (DNA that disperses); the middle piece: the metabolizing (ATP-producing) region; and the tail: the region of movement. (p. 1037) 20. Three small polar bodies, almost without cytoplasm, ensure that the fertilized egg cell has sufficient nutrient reserves on its way to the uterus. (p. 1049) 21. Menopausal events include decreased estrogen production, anovulatory ovarian cycle, and irregular menstrual periods that shorten and eventually stop altogether. Possible consequences of menopause include atrophy of the reproductive organs and breasts, vaginal dryness, painful intercourse, vaginal infections, irritability and mood swings, severe vasodilatation of the blood vessels in the skin (“hot flashes”), gradual thinning of the skin, loss of bone mass and a slow rise in cholesterol levels in the body Blood. (p. 1063) 22. Menarche is the first menstrual cycle that occurs when the adult pattern of gonadotropin cycles is reached. (p. 1053) 23. The path of a sperm from the male testes to the female uterine tubule is as follows: testes, epididymis, vas deferens, male urethra, vagina, uterus and fallopian tube. (pp. 1028-1030, 1042-1045) 24. When blood levels of luteinizing hormone fall, the corpus luteum begins to degenerate. Progesterone levels drop, depriving the endometrium of hormonal support, and the spiral arteries twist and spasm. Without oxygen, endometrial cells die, and when their lysosomes disintegrate, the functional layer “digests” itself. (pp. 1054-1056) 25. The vaginal epithelium harbors dendritic cells that act as antigen-presenting cells in the immune response and thus invading bacteria and viruses recognize and combat them early on. The cervical mucous glands secrete glycogen, which is anaerobically metabolized by vaginal mucosal cells to lactic acid, providing a low vaginal pH that is bacteriostatic. (pp. 1044-1045) 26. The mucus produced by these glands clears the urethra of urine debris before ejaculation occurs. (p. 1031) 27. His cremaster muscles contracted to bring his testicles closer to the warmth of his body wall. (p. 1026)

Critical Thinking and Clinical Application Problems 1. This patient has a prolapsed uterus, no doubt caused by tension in the pelvic floor muscles during her many pregnancies. Since she also has keloids, it can be assumed that the central tendon, to which these muscles attach, is severely damaged and many vaginal tears have occurred. (p. 1044) 2. The patient probably has a gonorrhea infection caused by the bacterium Neisseria gonorrhoeae. It is treated with penicillin and other antibiotics. If left untreated, it can lead to urethral strictures and inflammation of the entire male duct system. (p. 1058)

Copyright © 2010 Pearson Education, Inc.

345

346

3. No, she will not go through menopause because her ovaries will not be affected; You will continue to produce hormones. Tubal ligation is the severing or cauterizing of the fallopian tubes. (pp. 1042, 1096) 4. The man is asked if he has difficulty urinating or problems with impotence. The main test would be determining your sperm count. (p. 1038) 5. There is no continuity between the ovary and fallopian tube, and secondary oocytes are released into the abdominal cavity. The ovulated egg cell is “driven” towards the fallopian tube by the activity of the fimbriae and cilia. Although it is a longer route, eggs released from one side of the abdominal cavity may eventually enter the fallopian tube on the opposite side. (pp. 1042-1044)

Suggested Reading Alexander, N.J. "Barriers to Sexually Transmitted Diseases". Scientific American: Science & Medicine 3 (March/April 1996): 32-41. Brainard, J. "The Silent Accomplice of HIV." Science News 154 (September 1998): 158-159. Cho, C., et al. "Fertilin B defects in the semen of mice lacking Fertilin B". Science 281 (September 1998): 1857–1859. Christensen, Damaris. "Mammography Tests". Science News 161(17) (April 2002): 264-266. Curry, Donya. "Health Findings". Nation's Health 38(4) (May 2008): 18. Daly, Melissa. “Return of a Menace: Syphilis is Back. Here's what you need to know about it. Current Health 35(3) (November 2008): 1-4. Fackelmann, K. A. "Medicine for menopause." Science News 153 (1998 June): 392-393. Garbers, David L. "Ion Channels: Swimming with the Sperm." Nature 413 (6856) (October 2001): 579-582. Garnick, MB "Prostate Cancer". Scientific American 279 (December 1998): 74-83. Jegalian, Karin, and Bruce T. Lahn. "Why is the Y so weird?" Scientific American 284(2) (February 2001): 56-61. Jordan, VC "Estrogen Designer". Scientific American 279 (October 1998): 60-67. Kang-Decker, Ningling et al. "Lack of acrosome formation in Hrb-deficient mice". Science 294 (5546) (November 2001): 1531–1533. Kuiper, GJM, M Carlquist, and J Gustafsson. "Estrogen is a male and female hormone." Science & Medicine 5 (July/August 1998): 36-45. Muramatsu, Takashi. "Carbohydrate recognition in spermatogenesis". Science 295 (5552) (January 2002): 53-54. Nantel, F., et al. "Spermogenesis deficiency and germ cell apoptosis in CREMMant mice". Nature 380 (March 1996): 159-162. Pollard, J.W. "Modifiers of Estrogen Action." Science & Medicine 6 (July/August 1999): 38–47. Raloff, J. "Common Pollutants Harm Manhood." Science News 155 (April 1999): 213. Raloff, Janet. "Hormones: Here's the meat." Science News 161(1) (January 2002): 10-12. Seppa, N. "Soy Estrogens: Too Much of a Good Thing?" Science News 159(24) (June 2001): 375.

Copyright © 2010 Pearson Education, Inc.

Chapter 27

reproductive system

Smaglik, P. "Understanding playback language." Science News 151 (February 1997): 85. Strief, Dawn Mielke. "An overview of prostate cancer: diagnosis and treatment." MEDSURG Nursing 17(4) (August 2008): 258-269. Tilly, Jonathan L. "Commuting the Death Sentence: How Oocytes Try to Survive." Nature Reviews: Molecular Cell Biology 2 (11) (November 2001): 838-848. Wu, C. "Tempering Up with Postmenopausal Hormones." Science News 150 (November 1996): 293.

Copyright © 2010 Pearson Education, Inc.

347

28

pregnancy and human development

Goals

Events of fetal development

from egg to zygote

11. Indicate the length of the fetal period and note the main events of fetal development.

1. Describe the importance of sperm capacity. 2. Explain the slow blocking mechanism of polyspermia. 3. Define fertilization. Events in embryonic development: implantation of the zygote in the blastocyst 4. Explain the process and the result of the cleavage. 5. Describe the implementation. 6. Describe the formation of the placenta and list the functions of the placenta. Embryonic developmental events: gastrula to fetus 7. Name and describe the formation, location and function of the extra-embryonic membranes. 8. Describe the gastrulation and its consequences. 9. Define organogenesis and state the important role of the three primary germ layers in this process. 10. Describe the unique characteristics of the fetal circulation.

Effects of pregnancy on the mother 12. Describe the functional changes in the mother's reproductive, cardiovascular, respiratory and urinary systems during pregnancy. 13. List the effects of pregnancy on the mother's metabolism and posture. Labor (birth) 14. Explain how labor begins and describe the three stages of labor. Adaptations of the newborn to extrauterine life 15. Describe the events leading up to a newborn's first breath. 16. Describe the changes that occur in the fetal circulation after birth. Lactation 17. Explain how the breasts are prepared for lactation. Assisted reproductive technology and reproductive cloning 18. Describe some ART techniques including IVF, ZIFT and GIFT.

Suggested Lesson Plan I. Ovum to Zygote (pp. 1072-75; Figs. 28.1-28.3) A. Completion of Fertilization (pp. 1072-75; Figs. 28.1-28.3) 1. Fertilization occurs when a sperm with a The ovum fuses and forms a zygote.

348 Copyright © 2010 Pearson Education, Inc.

Chapter 28

pregnancy and human development

2. Millions of ejaculated sperm in the female reproductive tract are lost due to leakage from the vaginal canal, destruction by the acidic environment of the vagina, inability to expel cervical mucus, or destruction by the uterine defense cells. 3. In order to fertilize an egg, the sperm must be capacitated, a process in which the sperm cell membrane is weakened to allow the release of acrosomal hydrolytic enzymes. 4. When sperm adhere to the zona pellucida surrounding the egg, they undergo an acrosomal reaction that releases acrosomal enzymes into the egg. a. Hundreds of sperm must release their acrosomal enzymes before fertilization can take place. B. Once a sperm cell binds to membrane receptors on the oocyte membrane, its nucleus enters the oocyte cytoplasm. 5. Polyspermia or fertilization by more than one sperm results in a lethal chromosome count and should be avoided. a. Rapid blockade of polyspermia occurs when the oocyte membrane depolarizes, preventing similar binding by other sperm. B. The slow blockade of polyspermia leads to the destruction of sperm receptors and the formation of an inflamed membrane that removes other sperm from the surface of the oocyte. 6. After a spermatozoon enters an oocyte, it loses its tail and midsection and migrates to the center of the oocyte as the oocyte completes meiosis II. a. Upon completion of meiosis II, the male and female pronuclei fuse, producing a zygote that enters mitosis almost immediately.

II. Events of Embryonic Development: Implantation of the Zygote in the Blastocyst (pp. 1075-1078; Fig. 28.4-28.8) A. Pre-embryonic Development (pp. 1075-1078; Fig. 28.4-28.8) 1. Pre-embryonic development begins with fertilization and it continues with the movement of the pre-embryo towards the uterus where it implants itself in the uterine wall. 2. Mitotic divisions after fertilization occur without much growth between divisions, resulting in progressively smaller cells, a process called fission. a. The split forms two identical cells, blastomeres, which then within 72 hours form a morula, a hollow ball of cells. B. After 4-5 days, the blastocyst escapes the breakdown of the zona pellucida to implant in the uterine wall. 3. The implantation takes place after 6 to 7 days; The trophoblast attaches to the endometrium and produces enzymes that irritate the endometrium. a. The uterine capillaries become increasingly leaky and the trophoblast proliferates, forming cytotrophoblast and syncytiotrophoblast. B. Trophoblast cells secrete human chorionic gonadotropin (hCG) which acts on the corpus luteum. 4. Placentation is the formation of the placenta and the process of proliferation of trophoblasts. a. The placenta is fully functional as a nutritional, respiratory, excretory and hormonal organ by the end of the third month of pregnancy.

Copyright © 2010 Pearson Education, Inc.

349

350

Text and media guide to human anatomy and physiology

3. Events of Embryonic Development: Gastrula to Fetus (pp. 1079-1087; Figs. 28.9-28.14) A. Formation and Function of Embryonic Membranes (p. 1080) 1. During implantation, the blastocyst becomes a gastrula containing three primary cotyledons form and embryonic membranes develop. a. The amnion forms the transparent sac that contains the embryo and provides a buoyant environment that protects the embryo from physical trauma. B. The yolk sac is part of the intestine, produces the first blood cells and blood vessels, and is the source of gametes that migrate to the embryo to fertilize the gonads. C. The allantois is the structural base of the umbilical cord that connects the embryo to the placenta and becomes part of the urinary bladder. i.e. The chorion helps form the placenta and surrounds the embryonic body and all other membranes. B. Gastrulation: formation of the germ layer (pp. 1081-1083; Fig. 28.9) 1. Gastrulation is the process of transforming the two-layered germinal disc into a three-layered embryo containing three germ layers: ectoderm, mesoderm. and endoderm. 2. Gastrulation begins with the appearance of the primitive streak that defines the long axis of the embryo. a. From the endoderm arise the epithelial linings of the intestinal, respiratory, and genitourinary systems and associated glands. B. Mesoderm gives rise to all kinds of tissues that are not made of ectoderm or endoderm, such as muscle tissue. C. Structures of the nervous system and epidermis arise from the ectoderm. C. Organogenesis: Germ Layer Differentiation (pp. 1083-1087; Figs. 28.10-28.14) 1. Organogenesis is the formation of organs and organ systems; at the end of the embryonic period, all organ systems are recognizable. a. Neurulation, the formation of the brain and spinal cord, is the first event of organogenesis. B. As the embryo develops from a flat sheet of cells, it coils into a tube and the lower endoderm becomes the lining of the primordial gut. C. The mesodermal specialization forms the notochord and gives rise to dermis, parietal serosa, bone, muscle, cardiovascular structures, and connective tissue. i.e. At 3 1/2 weeks, the embryo has a vascular system and a beating heart. Y. Vascular changes include umbilical arteries and veins, a ductus venosus, and the foramen ovale and ductus arteriosus.

4. Events of Fetal Development (pp. 1087-89; Fig. 28.15; Table 28.1) A. The fetal period extends from 9 to 38 weeks and is a period of rapid growth of established body structures in the embryo (pp. 1087)-1089 ; Fig. 28.15; Table 28.1).

Copyright © 2010 Pearson Education, Inc.

Chapter 28

pregnancy and human development

B. During the first half of the fetal period, cells are still differentiating into specific cell types to form the various tissues of the body (pp. 1087-1089).

V. Effects of pregnancy on the mother (pp. 1089-90; Fig. 28.16) A. Anatomical changes (pp. 1089-90; Fig. 28.16) 1. The female genital organs and breasts become increasingly vascularized and fill with blood 2 The uterus enlarges dramatically, shifting the woman's center of gravity and causing a pronounced lumbar curvature (lordosis). 3. The placental production of the hormone relaxin causes the pelvic ligaments and symphysis to soften and relax. 4. There is a normal weight gain of about 28 pounds due to the growth of the fetus, maternal reproductive organs and breasts, and increased blood volume. B. Metabolic Changes (p. 1090) 1. As the placenta grows, it produces human placental lactogen which, along with estrogen and progesterone, promotes the maturation of the breasts for lactation. 2. Human placental lactogen also promotes fetal growth and exerts a glucose-sparing effect on maternal metabolism. 3. Human placental chorionic thyrotropin increases maternal metabolic rate. C. Physiological Changes (p. 1090) 1. Many women experience morning sickness during early pregnancy as their systems adjust to the increased levels of estrogen and progesterone. 2. Heartburn is usually the result of a shift in the esophagus, and constipation can occur due to decreased motility of the digestive tract. 3. The kidneys produce more urine because there is extra fetal metabolic waste. 4. Vital capacity and respiratory rate increase, but residual volume decreases, and many women experience shortness of breath or dyspnea. 5. Blood volume increases to meet the needs of the fetus, so blood pressure and heart rate increase, and cardiac output increases.

SEEN. Labor (birth) (pp. 1090-92; Figs. 28.17-28.18) A. Labor is the process of childbirth and generally occurs within 15 days of the estimated date of delivery, which is 280 days after the last menstrual period (p. 1090). B. Onset of labor (p. 1091; Fig. 28.17) 1. Estrogen levels peak, stimulating the uterine myometrial cells to produce abundant oxytocin receptors and antagonizing the sedative effects of progesterone on uterine muscles. 2. Fetal cells produce oxytocin, which promotes the release of prostaglandins from the placenta and further stimulates uterine contraction. 3. Increased emotional and physical stress activates the mother's hypothalamus and signals the release of oxytocin. 4. Expulsive contractions are promoted by a change in an adhesive protein, fetal fibronectin, which converts it into a lubricant. Copyright © 2010 Pearson Education, Inc.

351

352

Text and Media Instructor's Guide to Human Anatomy and Physiology C. Phases of Labor (pp. 1091-92; Fig. 28.18) 1. The dilation phase of labor extends from the onset of labor to the complete dilatation of the cervix. on the baby's head, about 10 cm in diameter. 2. The expulsion phase extends from full dilation to the moment the baby is born. a. When the baby is in the vertex or head-down position, the skull acts like a wedge to dilate the cervix. B. Coronation occurs when the baby's head stretches the vulva, and once the head comes out, the rest of the baby follows much more easily. C. After birth, the umbilical cord is clamped and cut. 3. During the placental stage, uterine contractions cause the placenta to detach from the uterine wall, followed by expulsion of the placenta and membranes (placenta).

VIII. Infant's Adaptations to Extrauterine Life (pp. 1092-1093) A. The Apgar score is an assessment of the infant's physiological status based on heart rate, respiration, skin color, muscle tone, and reflexes (pp. 1092 and 1093). B. Your first breath (p. 1093) 1. As the placenta stops removing carbon dioxide from the blood, it builds up in the baby's blood and produces acidosis, which signals the respiratory control centers. 2. The transition period is 6 to 8 hours after birth, characterized by intermittent waking periods during which the baby's heart rate, breathing patterns and body temperature fluctuate. C. Occlusion of Special Fetal Blood Vessels and Vascular Shunts (p. 1093) 1. After birth, the umbilical arteries and veins contract and become fibrous, becoming the medial umbilical ligaments, the superior vesical arteries, and the round ligament of the liver or the circular band. 2. The ductus venosus closes and eventually becomes the ligamentum venosum. 3. A flap of tissue covers and closes the foramen ovale and becomes the fossa ovale, while the ductus arteriosus contracts and becomes the ligamentum arteriosus.

VIII. Lactation (pp. 1093-1094; Fig. 28.19) A. Lactation is the production of milk by the hormone-controlled mammary glands (pp. 1093-1094; Fig. 28.19). 1. Rising levels of placental estrogen, progesterone, and lactogen stimulate the hypothalamus to produce prolactin-releasing hormone (PRH), which promotes prolactin secretion from the anterior pituitary gland. 2. Colostrum, a high-protein, low-fat product, is first secreted by the mammary glands, but after two to three days real milk is produced. 3. Nipple stimulation during lactation sends neural signals to the hypothalamus, resulting in the production of PRH and a prolactin surge that stimulates milk production for the next meal. 4. Oxytocin triggers the milk ejection reflex, which causes the release of milk from the alveoli of the mammary glands of both breasts. 5. The advantages of breast milk are: better absorption and more efficient metabolism of many components; antibodies and other chemicals that protect the baby; a natural laxative effect that helps prevent physiological jaundice; and promotion of the natural intestinal fauna. Copyright © 2010 Pearson Education, Inc.

Chapter 28

pregnancy and human development

IX. Assisted Reproductive Technology and Reproductive Cloning (p. 1094-97) A. Hormones can be used to increase production of sperm or egg cells, and surgery can be used to open blocked fallopian tubes (p. 1095). B. Assisted reproductive technology involves the surgical removal of ova from a woman's ovaries, fertilization of the ova, and their return to the woman's body (p. 1095). C. Cloning introduces a somatic cell nucleus into an egg cell (pp. 1096-1097).

Cross-references For more information on the topics discussed in Chapter 28, see the chapters listed below. 1. Chapter 2: Enzymes 2. Chapter 16: Hormones and hormone function; parathyroid hormone and calcium balance; oxytocin; Prolactin 3. Chapter 18: Fetal Heart 4. Chapter 19: Fetal Blood Vessels and Shunts; Varicose Veins 5. Chapter 21: Antibodies 6. Chapter 22: Acidosis and Respiratory Drive 7. Chapter 27: Oogenesis; secondary oocyte; vaginal environment; seeds; cervical mucus; sperm structure; oocyte structure; hypothalamic-pituitary control of the ovarian cycle; uterus and fallopian tubes; endometrium; corpus luteum and hCG; Ovarian and Menstrual Cycle

Laboratory correlations 1. Marieb, E.N., and S.J. mitchell Laboratory manual of human anatomy and physiology : fetal porcine and feline versions. Ninth edition updates. Benjamin Cummings, 2009. Exercise 44: Studying Embryonic Development 2. Marieb, E.N. and S.J. Mitchell. Human Anatomy and Physiology Laboratory Manual: Major Version. Eighth edition update. Benjamin Cummings, 2009. Exercise 44: Embryonic Development Survey

Teaching Tips 1. Emphasize the difference between the terms concept, embryo, and fetus (and the periods associated with them). 2. Emphasize that the first cell divisions in the product of conception increase the total number of cells but do not lead to an increase in cell size. The cells get smaller and smaller until the area ruptures. 3. When discussing maintenance of the corpus luteum (which initially maintains pregnancy and is under the hormonal control of trophoblast cells), mention that measuring hCG levels would be an ideal indicator of pregnancy (home PET tests, blood). . 4. Point out that the blastocyst is actually embedded in the wall of the endometrium and is not attached to the surface as some students initially assume. 5. Point out the dual origin of the placenta.

Copyright © 2010 Pearson Education, Inc.

353

354

Text and Media Human Anatomy and Physiology Teacher Guide 6. Emphasize that from the mother's perspective, the placenta is just another organ that draws resources from the mother's blood supply. This idea is useful for establishing the placenta as an organ of exchange. 7. Emphasize that embryonic/fetal blood does not come into contact with maternal blood under normal circumstances, but most substances (including the gamma class of immunoglobulins) cross the placenta and enter the embryonic/foetal circulation. 8. Take the time to highlight the embryonic/fetal membranes as the anatomical orientation of these membranes is difficult for many students to visualize. 9. Mention that the yolk sac is not the source of nutrients for the egg like in birds and reptiles, but rather an early site of blood formation. 10. Point out an interesting point that "eating for two" is a common belief that has no physiological basis. 11. Check the hypothalamic and pituitary control of the ovarian cycle. 12. Show the logic behind the various modifications to fetal circulation and how these shunts should be rerouted when the umbilical cord is cut. 13. Discussing the changes that occur in the mother during pregnancy, carefully emphasize each one: urine output should increase, because the fetus adds a significant amount of waste to the mother's blood; blood volume increases due to the mother's over-consumption of resources, etc. 14. The 1983 NOVA Miracle of Life video is one of the best available, showing developmental events from fertilization to parturition. It is worth taking the time to introduce this videotape, especially if you don't use any other videotape. 15. Distinguish clearly between the milk production process and the milk flow in the milk ducts.

Activities/Demonstrations 1. Audiovisual materials listed under Multimedia in the Classroom and Laboratory. 2. Ask students to bring a recent article that discusses the effects of drug use or maternal diseases (such as AIDS, herpes, etc.) on fetal well-being. 3. Obtain a fresh placenta from a local hospital to demonstrate the anatomical features of this vital structure. 4. Use a pregnancy model to see the development, position and delivery of the fetus. 5. Use a manikin and drawstring bag to demonstrate fetal positioning for vaginal delivery and the rotational movements that lead to delivery. 6. Use a doll and drawstring pouch to illustrate abnormal birthing positions. 7. Use a series of models and/or charts to illustrate the various stages of embryonic and fetal development. Students are often overwhelmed by development terminology. 8. If available, show embryos and fetuses at different stages of development.

Critical Thinking/Discussion Points 1. Discuss the importance of folic acid in preventing neural tube defects. 2. Examine the drastic changes the fetus undergoes at birth and how these changes can be minimized. 3. Examine the pros and cons of determining when life begins (make sure both sides of the issue are presented). 4. Discuss the methods available to induce pregnancy (eg, artificial insemination, in vitro fertilization, etc.) and what care should be taken by those who choose to use these methods. Copyright © 2010 Pearson Education, Inc.

Chapter 28

pregnancy and human development

5. Student assignment for class discussion: a. Define episiotomy and explain why this procedure is performed. B. Define Down syndrome (trisomy of chromosome 21) and indicate in which maternal age group it occurs most frequently.

Library Research Topics 1. Research the pros, cons, and contraindications of exercising during pregnancy. 2. Research the types of birth presentations and note the symptoms, prognosis, and difficulties encountered with each type. 3. Examine different types of birth defects by symptom category (eg, skeletal system, circulatory system, etc.). 4. Investigate various environmental influences such as alcohol, drugs (legal and illegal), infectious diseases and the like on embryological and fetal development. 5. Examine the different methods of contraception, including those currently in use, as well as methods that have been developed. 6. Explore the benefits of breastfeeding for both the child and the mother. 7. Examine fetal and infant issues related to the mother's lifestyle, such as STDs, infectious diseases, alcoholism and TD, AIDS, etc. 8. Examine the relative advantages and disadvantages of traditional birthing methods compared to underwater births or births in hot water , poorly lit rooms, etc.

Online lab and multimedia classroom resources for students

www.myaandp.com Below is the organization of the Chapter Guide page in myA&P™. The Chapter Guide organizes all of the chapter-specific online media resources for Chapter 28 in one convenient location, with eBook links to each section of the textbook. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more. Objectives Section 28.1 Egg to zygote (pp. 1072–75) Artist's caption: Detailed anatomy of vascular relationships at base of mature decidua (Fig. 28.8, p. 1080) Memory game: Embryonic development Section 28.2 Events of embryonic development: Zygote to blastocyst implantation ( pp. 1075-1078) Case Study: Genetics/Pregnancy and Human Development Section 28.3 Embryonic Development Events: Gastrula to Fetus (pp. 1079-1087) Section 28.4 Fetal Development Events (pp. 1087-1089) Case Study: Birth Defects Section 28.5 Effects of Pregnancy on the mother (pp. 1089-90) Section 28.6 Birth (birth) (pp. 1090-92) Copyright © 2010 Pearson Education, Inc.

355

356

Text and Media Teacher's Guide to Human Anatomy and Physiology Activity: Oxytocin and Labor Section 28.7 Infant Adaptations to Extrauterine Life (pp. 1092-93) Section 28.8 Breastfeeding (pp. 1093-94) Section 28.9 Assisted Reproductive Technology and Reproductive Cloning (p. 1094 –1097) Chapter Summary MP3 Teacher Session: Egg Implantation Crossword 28.1 Crossword 28.2 Web Links Chapter Tests Artistic Labeling Test Matching Test Multiple Choice Test Multiple Choice Test Select Practice Test Chapter Learning Tools Histology Atlas myeBook Flashcards Glossary

The myA&P™ Chapter Guide resources are also available in the Chapter Contents section of CourseCompass™. Students can also access A&P Flix animations, MP3 tutorial sessions, Interactive Physiology® 10 System Suite, Practice Anatomy Lab™ 2.0, PhysioEx™ 8.0 and much more.

Media For information on AV vendors, see the AV Resource Guide in Appendix A.

Video 1. A New Life (FHS; 28 min., 1984). From the award-winning series The Living Body, this video explores the events leading up from the fertilization of a cell to the development of a human baby. 2. Premature Infant Care (ESF; 19 min). It highlights the risks of preterm labor, the challenges faced by preterm babies, and the tools available to save young lives. Helps students understand the issues related to preterm birth. 3. Gathering (FHS; 28 min., 1984). Part of the award-winning The Living Body series, this video covers the physiological events underlying reproduction. 4. NOVA® Life's Greatest Miracle (PBS; 60 min., 2002). A sequel to NOVA's 1983 video The Miracle of Life. NOVA collaborates with Swedish science photographer Lennart Nilsson to show the emergence of human life in more detail. The sequences filmed by Nilsson include the journey from sperm to egg. 5. NOVA® The Miracle of Life (PBS; 60 min., 1983). Swedish photographer Lennart Nilsson takes you on a journey inside the human womb in this Emmy Award-winning show. It travels down the fallopian tube, observing the sperm and egg, then the development of the embryo, and finally the birth of a child. Copyright © 2010 Pearson Education, Inc.

Chapter 28

pregnancy and human development

6. Overcoming Infertility (FHS; 28 min, 2006). According to the Centers for Disease Control and Prevention, infertility affects more than 6 million men and women in the United States. This program highlights advances in assisted reproductive technology. Interviews with renowned fertility experts and patients who have undergone fertility treatment provide case studies. 7. Prenatal development: a life in development (IM; 26 min., 2005). Follow the transformation from a single-celled zygote to a fully functional human in just 266 days. Explore the three stages of prenatal development and discuss the organs and structures that nourish and protect the fetus. 8. Reproduction: Actions in the future (FHS; 26 min., 1984). From the series The Living Body. It shows the characteristics of sperm and egg cells and how each contains a partial blueprint for future offspring. The mechanism of cell division is shown by photomicrographs; The mechanisms of inheritance are carefully described. 9. Small Miracles: Healing Deadly Conditions in the Womb (FHS; 51 min., 1995). An introduction to the diagnosis and treatment of babies with life-threatening diseases in the womb.

Software 1. The Embryonic Disc (IM; Windows). Tracing the formation of the human embryo from fertilization to development, this CD-ROM presents the first month of life on one page, linking each day to an illustrated description of the key events.

Reading Enhancement Material Thumbnails of all figures in Chapter 28 can be found in Appendix B.

Index Slide/Instructor Resource DVD Figure 28.1 Figure Figure Figure Figure Figure Figure

28,2 28,3 28,4 28,5 28,6 28,7

Figure 28.8 Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure

28,9 28,10 28,11 28,12 28,13 28,14 28,15 28,16 28,17 28,18 28,19

Diagrams showing the approximate size of a human concept from fertilization to the early fetal stage. Sperm penetration and cortical response (slow blockage to polyspermia). fertilization events. Cleavage of zygote to blastocyst. Blastocyst implantation. Hormonal changes during pregnancy. Placentation events, early embryonic development and extraembryonic membrane formation. Detailed anatomy of the vascular relationships in the mature basal decidua. Formation of the three primary cotyledons. Early mesodermal neurulation and differentiation. Folding of the embryonic body, lateral views. endodermal differentiation. Flow chart showing the main derivatives of the embryonic cotyledons. Circulation in the fetus and newborn. Photographs of a developing fetus. Relative size of the uterus before conception and during pregnancy. Hormonal induction of labor. Birth. Milk production and the positive feedback mechanism of the milk ejection reflex. Copyright © 2010 Pearson Education, Inc.

357

358

Text and Media Teacher's Guide to Human Anatomy and Physiology Table 28.1 Developmental events in the fetal period A closer look at to be or not to be

Answers to the questions at the end of the chapter The answers to the multiple choice and matching questions appear in Appendix G of the main text.

Short Answer Essay Questions 15. Human chorionic gonadotropin (hCG) is used as a pregnancy test during early pregnancy because it is secreted by trophoblast cells to stimulate the corpus luteum to keep producing progesterone and estrogen. HCG levels are detected in the mother's blood one week after conception. Levels remain high until the end of the second month and then drop to a low level in the fourth month. At this point, the placenta has taken over the production and excretion of progesterone and estrogen. (p. 1077) 16. a. The fertilization process involves several steps. First, the sperm deposited in the vagina must be trained; That is, their membranes must become brittle in order for hydrolytic enzymes to be released from their acrosomes. The acrosomal reaction is the release of acrosomal enzymes (hyaluronidase, acrosin, proteases and others) that takes place near the oocyte. Hundreds of acrosomes must be disrupted to disrupt the intercellular cement that holds the granulosa cells together and to digest the foramina in the zona pellucida. Once a pathway has been opened and an individual spermatozoon contacts receptors on the oocyte membrane, its nucleus is drawn into the oocyte cytoplasm. As soon as the plasma membrane of a sperm comes into contact with the membrane of the ovum, the sodium channels open and ionic sodium enters the ovum from the extracellular space, depolarizing its membrane. Depolarization causes ionic calcium to be released into the oocyte cytoplasm. This increase in intracellular calcium levels triggers the cortical response and activates the oocyte. The activated secondary oocyte completes meiosis II, forming the nucleus of the oocyte and expelling the second polar body. The nuclei of the egg and sperm swell, becoming female and male pronuclei, and move closer together as a mitotic spindle develops between them. Then the membranes of the pronuclei rupture and release their chromosomes near the spindle. The combination of the maternal and paternal chromosomes constitutes the act of fertilization and produces the diploid zygote. B. The effect of fertilization is the formation of a single cell (zygote) containing the chromosomes of the egg and sperm and determining the sex of the offspring. (pp. 1072-1075) 17. As daughter cells divide, they become progressively smaller, resulting in cells with a high surface-to-volume ratio, yielding a greater number of cells to use as building blocks for the construction of the embryo to serve . . (p. 1075) 18. a. Viability of the corpus luteum relies on human chorionic gonadotropin secreted by trophoblast cells of the blastocyst, which bypasses the pituitary-ovarian controls and induces continuous production of estrogen and progesterone to maintain the endometrium. B. The corpus luteum must remain functional after implantation until the placenta can assume hormone-producing functions; Otherwise, the endometrium is not preserved, and the concept is shed during menstruation. (p. 1075)

Copyright © 2010 Pearson Education, Inc.

Chapter 28

pregnancy and human development

19. The placenta consists of embryonic (trophoblastic) and maternal (endometrial) tissue. When the trophoblast acquires a layer of mesoderm, it becomes the chorion. The chorion ejects chorionic villi, which come into contact with maternal blood. Oxygen and nutrients diffuse from maternal to embryonic blood; embryonic debris diffuses from the embryo into the mother's circulatory system. (p. 1078) 20. When the plasma membrane of a sperm comes into contact with the membrane of the ovum, sodium channels open and ionic sodium enters the ovum from the extracellular space, depolarizing the membrane. This "rapid polysperm block" prevents other sperm from merging with the egg. This is followed by the cortical response that represents the "slow blockade of polyspermia". (p. 1073) 21. The process of gastrulation gives rise to the three primary germ layers, the ectoderm, mesoderm and endoderm, from which all tissues are formed. (p. 1081) 22. The breech presentation is the first presentation of the buttocks. Two problems with breech presentation are more difficult delivery and the baby having trouble breathing. (p. 1092) 23. Factors that trigger uterine contractions include high levels of estrogen; Production of oxytocin by the fetus, which acts on the placenta to stimulate the production and release of prostaglandins; and activation of the hypothalamus to produce oxytocin, which is released by the posterior pituitary gland. (p. 1091) 24. The flattened germinal disc assumes a cylindrical body shape when its sides are turned in and ascending from the yolk sac into the amniotic sac. At the same time, the head and tail regions are bent down. All this folding gives the month-old embryo a tadpole-like shape. The process is shown in Figure 28.11 on p. 11. 1083

Critical Thinking Problems and Clinical Application 1. (c). Most important developmental events occur during the first three months of pregnancy, and events that are blocked for any reason never occur because development is precisely timed. The evaluation should be performed to analyze possible problems. (pp. 1085, 1087-1089) 2. An episiotomy is a midline incision from the lateral or posterior vaginal opening into the rectum. It is done to reduce tissue tears when the baby's head leaves the perineum. (p. 1091) 3. a. The woman was in the labor phase, in the expulsion phase. B. You probably wouldn't have time to go to the hospital. Typically, it takes 50 minutes for the first birth and 20 minutes for subsequent births to occur once the ebullient stage is reached. A 60-mile trip would take over an hour. (p. 1091) 4. Mary's fetus could have respiratory problems or even birth defects as a result of her