Human Physiology Chapter 1 Book PDF

A01_SILV5197_08_SE_FM.indd 1 20/12/2017 21:24  Contents in Brief UNIT 1 Basic Cell Processes: Integration and Coordination 1 Introduction to Physiology 1...

A01_SILV5197_08_SE_FM.indd 1 20/12/2017 21:24  Contents in Brief UNIT 1 Basic Cell Processes: Integration and Coordination 1 Introduction to Physiology 1 2 Molecular Interactions 28 3 Compartmentation: Cells and Tissues 58 4 Energy and Cellular Metabolism 92 5 Membrane Dynamics 121 6 Communication, Integration, and Homeostasis 164 UNIT 2 Homeostasis and Control 7 Introduction to the Endocrine System 194 8 Neurons: Cellular and Network Properties 223 9 The Central Nervous System 271 10 Sensory Physiology 307 11 Efferent Division: Autonomic and Somatic Motor Control 355 12 Muscles 374 13 Integrative Physiology I: Control of Body Movement 414 UNIT 3 Integration of Function 14 Cardiovascular Physiology 432 15 Blood Flow and the Control of Blood Pressure 476 16 Blood 510 17 Mechanics of Breathing 532 18 Gas Exchange and Transport 562 19 The Kidneys 587 20 Integrative Physiology II: Fluid and Electrolyte Balance 618 UNIT 4 Metabolism, Growth, and Aging 21 The Digestive System 654 22 Metabolism and Energy Balance 692 23 Endocrine Control of Growth and Metabolism 728 24 The Immune System 754 25 Integrative Physiology III: Exercise 786 26 Reproduction and Development 800 CVR_SILV5197_08_SE_FEP.indd 2 12/2/17 6:54 AM  Strategies for Success Top Ten Ways to Word Roots for Physiology Succeed in Classes that Simplify physiology and medicine by learning Latin and Use Active Learning Greek word roots. The list below has some of the most common ones. By Marilla Svinicki, Ph.D., former Director of the Using the list, can you figure out what hyperkalemia University of Texas Center for Teaching Effectiveness means?* 1. Make the switch from an authority-based a- or an- without, absence hypo- beneath or deficient conception of learning to a self-regulated anti- against inter- between conception of learning. Recognize and accept -ase signifies an enzyme intra- within your own responsibility for learning. auto self -itis inflammation of bi- two kali- potassium 2. Be willing to take risks and go beyond what is brady- slow leuko- white presented in class or the text. cardio- heart lipo- fat 3. Be able to tolerate ambiguity and frustration cephalo- head lumen inside of a hollow tube in the interest of understanding. cerebro- brain -lysis split apart or rupture contra- against macro- large 4. See errors as opportunities to learn rather than -crine a secretion micro- small failures. Be willing to make mistakes in class or in crypt- hidden mono- one study groups so that you can learn from them. cutan- skin multi- many 5. Engage in active listening to what’s happening in -cyte or cyto- cell myo- muscle class. de- without, lacking oligo- little, few 6. Trust the instructor’s experience in designing di- two para- near, close class activities and participate willingly if not dys- difficult, faulty patho-, -pathy related to enthusiastically. -elle small disease -emia in the blood peri- around 7. Be willing to express an opinion or hazard a poly- many endo- inside or within guess. post- after epi- over 8. Accept feedback in the spirit of learning rather erythro- red pre- before than as a reflection of you as a person. exo- outside pro- before extra- outside pseudo- false 9. Prepare for class physically, mentally, and gastro- stomach re- again materially (do the reading, work the problems, -gen, -genie produce retro- backward or behind etc.). gluco-, glyco- sugar or sweet semi- half 10. Provide support for your classmate’s attempts to hemi- half sub- below learn. The best way to learn something well is to hemo- blood super- above, beyond teach it to someone who doesn’t understand. hepato- liver supra- above, on top of homo- same tachy- rapid Dr. Dee’s Eleventh Rule: hydro- water trans- across, through DON’T PANIC! Pushing yourself beyond the comfort hyper- above or excess zone is scary, but you have to do it in order to improve. * Hyper = excess, kali = potassium, -emia = in the blood, or elevated blood potassium CVR_SILV5197_08_SE_FEP.indd 3 12/2/17 6:54 AM  Owner’s Manual Welcome to Human Pattern recognition is important for all healthcare Physiology! As you professionals, so you can begin to develop this skill by begin your study of learning the key concepts of physiology that repeat the human body, one over and over as you study different organ systems. of your main tasks Chapter 1 includes two special Focus On features: one will be to construct on concept mapping, a study strategy that is also used for yourself a global for decision-making in the clinics, and one on construct- view of the body, its ing and interpreting graphs. The Running Problem systems, and the many in Chapter 1 introduces you to effective ways to find processes that keep the systems working. This “big information on the Internet. picture” is what physiologists call the integration of Be sure to look for the Essentials and Review fig- systems, and it is a key theme in this book. To integrate ures throughout the book. These figures distill the information, however, you must do more than simply basics about a topic onto one or two pages, much as memorize it. You need to truly understand it and be the Anatomy Summaries do. My students tell me they able to use it to solve problems that you have never find them particularly useful for review when there encountered before. If you are headed for a career in isn’t time to go back and read all the text. the health professions, you will do this in the clinics. If We have also retained the four approaches to you plan a career in biology, you will solve problems in learning physiology that proved so popular since this the laboratory, field, or classroom. Analyzing, synthe- book was first published in 1998. sizing, and evaluating information are skills you need to develop while you are in school, and I hope that the 1. Cellular and Molecular Physiology features of this book will help you with this goal. Most physiological research today is being done at One of my aims is to provide you not only with in- the cellular and molecular level, and there have been formation about how the human body functions but many exciting developments in molecular medicine and also with tips for studying and problem solving. Many physiology in the 10 years since the first edition. For ex- of these study aids have been developed with the input ample, now scientists are paying more attention to pri- of my students, so I think you may find them particu- FIG. 3.5 Cilia and flagella mary cilia, the single cilium that larly helpful. (a) Cilia on surface of respiratory epithelium occurs on most cells of the body. On the following pages, I have put together a brief Primary cilia are thought to play tour of the special features of the book, especially those a role in some kidney and other that you may not have encountered previously in text- diseases. Look for similar links books. Please take a few minutes to read about them so between molecular and cellular that you can make optimum use of the book as you study. biology, physiology, and medi- Each chapter begins with a list of Learning Out- SEM × 1500 cine throughout the book. This image was taken with a scanning electron comes to guide you as you read the chapter. Within the chapters look for the Running Problem, Phys in Action, 2. Physiology as a Dynamic Field and Try It! activities. Phys in Action are online video clips Physiology is a dynamic discipline, with numerous that I created with the assistance of some of my stu- unanswered questions that merit further investigation dents. Look for and research. Many of the “facts” presented in this text Play Phys in Action the references to are really only our current theories, so you should be @Mastering Anatomy & Physiology Mastering A&P prepared to change your mental models as new infor- in the figures mation emerges from scientific research. with associated Phys in Action clips, and watch Kevin and Michael as they demonstrate physiology in action. EMERGING CONCEPTS CVR_SILV5197_08_SE_FEP.indd 4 12/2/17 6:54 AM  How to Use this Book 3. An Emphasis on Integration Also, be sure to look at the back of the text, where we have combined the index and glossary to save time The Integration between Systems of the Body The organ systems when you are looking up unfamiliar words. The appen- Integumentary System of the body do not dices have the answers to the Concept Check questions, Respiratory system work in isolation, Figure and Graph Questions, and end-of-chapter ques- Nervous system although we study tions, as well as them one at a time. reviews of physics, To emphasize the Endocrine system logarithms, and Digestive system integrative nature Circulatory basic genetics. The system of physiology, three back end papers chapters (Chapters include a periodic 13, 20, and 25) focus Musculoskeletal table of the ele- Urinary system on how the physi- system ments, diagrams Reproductive ological processes of system of anatomical multiple organ sys- positions of the tems coordinate with body, and tables each other, especially when homeostasis is challenged. with conversions and normal values of blood compo- nents. Take a few minutes to look at all these features 4. A Focus on Problem Solving so that you can make optimum use of them. One of the most valuable life skills students should acquire is the ability to think critically and use informa- It is my hope that by reading this book, you will de- tion to solve problems. As you study physiology, you velop an integrated view of physiology that allows you should be prepared to practice these skills. You will find to enter your chosen profession with respect for the a number of features in this book, such as the Concept complexity of the human body and a clear vision of the Check questions and Figure and Graph Questions. These potential of physiological and biomedical research. May “test yourself” questions are designed to challenge you find physiology as fun and exciting I do. Good luck your critical thinking and analysis skills. In each chapter, with your studies! read the Running Problem as you work through the Warmest regards, text and see if you can apply what you’re reading to Dr. Dee (as my students call me) the clinical scenario described in the problem. [email protected] Phys in Action Video Topics: Try It Activities: pp. 130–131 Fig. 5.4 Osmolarity & Tonicity p. 21 Graphing pp. 154–155 Fig. 5.23 Membrane Potential p. 135 Membrane Models (Lipid bylayer) pp. 458–459 Fig.14.15 Electrocardiogram p. 251 Action Potentials p. 494 Fig. 15.14 Cardiovascular Control p. 325 Salty-Sweet Taste Experiment p. 545 Fig. 17.7 The Spirometer p. 468 Frank-Starling Law of the Heart p. 549 Fig. 17.10 Respiratory Pressure p. 605 Insulin p. 557 Fig. 17.13 Alveolar Gases p. 682 Oral Rehydration Therapy p. 573 Fig. 18.7 Hemoglobin-Oxygen Transport p. 610 Fig. 19.13 Renal Clearance p. 793 Fig. 25.8 Blood Pressure & Exercise CVR_SILV5197_08_SE_FEP.indd 5 12/2/17 6:54 AM  EIGHTH EDITION AN INTEGRAT PPROACH UNIVERSITY OF TEXAS, AUSTIN with contributions by Bruce R. Johnson, Ph.D. and William C. Ober, M.D. ILLUSTRATION COORDINATOR Claire E. Ober, R.N. ILLUSTRATOR Anita lmpaglizzo, ILLUSTRATOR Andrew C. Silverthorn, M.D. CLINICAL CONSULTANT @ Pearson  Courseware Portfolio Manager: Lauren Harp Art Project Manager: Stephanie Marquez, Imagineering Art LLC Content Producer: Deepti Agarwal Illustrators: William C. Ober, Anita Impagliazzo, and Cliare E. Ober Managing Producer: Nancy Tabor Design Manager: Maria Guglielmo Walsh Courseware Director, Content Development: Barbara Yien Interior Designer: Gary Hespenheide Courseware Editorial Assistant: Dapinder Dosanjh Cover Designer: Gary Hespenheide Rich Media Content Producer: Nicole Constantine Rights & Permissions Project Manager: Katrina Mohn, Mastering Content Developer, Science: Lorna Perkins Cenveo Publisher Services Full-Service Vendor: SPi Global Rights & Permissions Management: Ben Ferrini Copyeditor: Alyson Platt Manufacturing Buyer: Stacey Weinberger, LSC Communications Product Marketing Manager: Wendy Mears Cover Photo: Motor Neuron in Muscle Credit: Kent Wood/Science Source Copyright ©2019, 2016, 2013, 2012 Pearson Education, Inc. All rights reserved. Printed in the United States of America. This publication is protected by copyright, and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise. For information regarding permissions, request forms and the appropriate contacts within the Pearson Education Global Rights & Permissions department, please visit www.pearson.com. Acknowledgements of third party content appear on page C-1, which constitutes an extension of this copyright page. PEARSON, ALWAYS LEARNING, Mastering™ A&P, BioFlix, and A&P Flix are exclusive trademarks in the U.S. and/or other countries owned by Pearson Education, Inc. or its affiliates. Unless otherwise indicated herein, any third-party trademarks that may appear in this work are the property of their respective owners and any references to third-party trademarks, logos or other trade dress are for demonstrative or descriptive purposes only. Such references are not intended to imply any sponsorship, endorsement, authorization, or promotion of Pearson’s products by the owners of such marks, or any relationship between the owner and Pearson Education, Inc. or its affiliates, authors, licensees or distributors. Library of Congress Cataloging-in-Publication Data Catalogue in Publication Data is on file with the Library of Congress ISBN 10: 0-13-460519-5; ISBN 13: 978-0-13-460519-7 (Student edition) 1 18 ISBN 10: 0-13-470434-7; ISBN 13: 978-0-13-470443-0 (Instructor’s Review Copy) www.pearson.com A01_SILV5197_08_SE_FM.indd 2 12/14/17 12:39 AM  ABOUT THE AUTHOR DEE UNGLAUB SILVERTHORN Teaching Award, the 2009 Out- studied biology as an undergraduate standing Undergraduate Science at Newcomb College of Tulane Uni- Teacher Award from the Society versity, where she did research on for College Science Teachers, the cockroaches. For graduate school, American Physiological Society’s she switched to studying crabs and Claude Bernard Distinguished Lec- received a Ph.D. in marine science turer and Arthur C. Guyton Physi- from the Belle W. Baruch Institute ology Educator of the Year, and for Marine and Coastal Sciences at multiple awards from UT–Austin, the University of South Carolina. including the Burnt Orange Apple Her research interest is epithelial Award. The first edition of her transport, and most recently work textbook won the 1998 Robert W. in her laboratory has focused on Hamilton Author Award for best transport properties of the chick Michael Chirillo, Dee Silverthorn, and Kevin Christmas textbook published in 1997–1998 allantoic membrane. Her teaching by a University of Texas faculty career started in the Physiology Department at the Medical Uni- member. Dee was the president of the Human Anatomy and versity of South Carolina but over the years she has taught a wide Physiology Society in 2012–2013, has served as editor-in-chief of range of students, from medical and college students to those still Advances in Physiology Education, and is currently chair of the preparing for higher education. At the University of Texas–Aus- American Physiological Society Book Committee. She works with tin, she teaches physiology in both lecture and laboratory settings, members of the International Union of Physiological Sciences to and instructs graduate students on developing teaching skills in the improve physiology education in developing countries, and this life sciences. In 2015 she joined the faculty of the new UT-Austin book has been translated into seven languages. Her free time is Dell Medical School. She has received numerous teaching awards spent creating multimedia fiber art and enjoying the Texas hill and honors, including a 2011 UT System Regents’ Outstanding country with her husband, Andy, and their dogs. About the Illustrators William C. Ober, M.D. (art coordinator and illustrator) received Claire E. Ober, R.N. his undergraduate degree from Washington and Lee University (illustrator) practiced pedi- and his M.D. from the University of Virginia. He also studied in atric and obstetric nursing the Department of Art as Applied to Medicine at Johns Hopkins before turning to medical University. After graduation, Dr. Ober completed a residency in illustration as a full-time Family Practice and later was on the faculty at the University of career. She returned to Virginia in the Department of Family Medicine and in the De- school at Mary Baldwin partment of Sports Medicine. He also served as Chief of Medi- College where she received cine of Martha Jefferson Hospital in Charlottesville, VA. He is her degree with distinction currently a visiting Professor of Biology at Washington & Lee Uni- in studio art. Following a versity, where he has taught several courses and led student trips to five-year apprenticeship, she has worked as Dr. Ober’s partner in the Galapagos Islands. He was part of the Core Faculty at Shoals Medical and Scientific Illustration since 1986. She was also on the Marine Laboratory, where he taught Biological Illustration for 22 Core Faculty at Shoals Marine Laboratory and co-taught Biologi- years. The textbooks illustrated by Medical & Scientific Illustra- cal Illustration at both Shoals Marine Lab and at Washington and tion have won numerous design and illustration awards. Lee University. iii A01_SILV5197_08_SE_FM.indd 3 12/14/17 12:39 AM  iv ABOUT THE AUTHORS About the Clinical Consultant About the Contributor Andrew C. Silverthorn, Bruce Johnson, Ph.D. M.D. is a graduate of the is a Senior Research Asso- United States Military ciate in the Department of Academy (West Point). He Neurobiology and Behavior at served in the infantry in Cornell University. He earned Vietnam, and upon his return biology degrees at Florida entered medical school at the State University (B.A.), Florida Medical University of South Atlantic University (M.S.), Carolina in Charleston. He and at the Marine Biological was chief resident in family Laboratory in Woods Hole medicine at the University (Ph.D.) through the Boston of Texas Medical Branch, Galveston, and is currently a family University Marine Program. For three decades, he has led Cor- physician in solo practice in Austin, Texas. When Andrew is not nell’s highly-praised Principles of Neurophysiology course, in busy seeing patients, he may be found on the golf course or play- which students receive hands-on instruction in principles and ing with his two rescue dogs, Molly and Callie. methods in neurophysiology. He is a coauthor of Crawdad: a CD- ROM Lab Manual for Neurophysiology and the Laboratory Manual for Physiology. Bruce has directed and taught in neuroscience fac- ulty workshops sponsored by NSF (Crawdad), ADInstruments (Crawdad and CrawFly), the Grass Foundation and the Faculty for Undergraduate Neuroscience (FUN). He has also lead work- shops and neuroscience courses at the Universities of Copenha- gen (Denmark), Cologne (Germany), Ibadan (Nigeria), and the Marine Biological Laboratory. Bruce has been named a Most Influential Faculty Member by the graduating senior class at Cornell and awarded the John M. and Emily B. Clark Award for Distinguished Teaching at Cornell. His other teaching awards include the FUN Educator of the Year Award, FUN Career Ser- vice Award, and co-recipient of the 2016 Award for Education in Neuroscience, sponsored by the Society for Neuroscience. He is currently the Editor-in-Chief of the Journal of Undergraduate Neuroscience Education. Bruce’s research addresses the cellular and synaptic mechanisms of motor network plasticity. A01_SILV5197_08_SE_FM.indd 4 12/14/17 12:39 AM  DEDICATION The 8th edition is dedicated to my colleagues who read every word of the first edition man- uscript and provided valuable feedback that helped shape the book. Park City, Utah, June 1995 (Standing, L to R): Judy Sullivan, Patricia Munn, Dee Silverthorn, Mary Ann Rokitka, Richard Walker, Pat Berger, Norman Scott (Seated) Shana Ederer, Prentice Hall development editor v A01_SILV5197_08_SE_FM.indd 5 12/14/17 12:39 AM  This page intentionally left blank A01_SILV5197_08_SE_FM.indd 6 12/14/17 12:39 AM  NEW TO THIS EDITION The Eighth Edition of Human Physiology: An Integrated Approach builds Chapter 6 Communication, Integration, and Homeostasis upon the thorough coverage of integrative and molecular physiology topics that have always been the foundation of this book. The big- Juxtacrine signaling gest change is a completely revised Chapter 24 on immunology. This Updated information on NIH Common Fund’s Building Blocks, Biological Pathways, and Networks Program field has expanded dramatically since the First Edition published in 1997, and it was time to step back and re-think the presentation Updated the discussion on cytokine families of this complicated and complex subject. Neurophysiology is also Re-classified receptor-enzymes as catalytic receptors changing rapidly, requiring multiple updates in Chapters 8 through GPCR for eicosanoids 11. In nearly every chapter the latest developments in research and Chapter 7 Introduction to the Endocrine System medicine meant changes to the presentation of information. Continuing the revision of the art introduced in the Seventh Updated information on calcitonin gene-related peptide Edition, we created additional Review and Essentials figures that Updated information on melatonin and melatonin-related drugs students can use for quick review as well as new Anatomy Sum- maries and concept maps. Figures from previous editions that were Chapter 8 Neurons: Cellular and Network Properties significantly modified or eliminated are still available to instructors on the Instructor’s DVD and in the Instructor Resources area of Update on mechanisms of axonal transport and associ- ated diseases: dynein, kinesin, fragile X, Alzheimer’s, Mastering A&P. microcephaly In addition to the online Phys in Action videos that are ref- erenced in related figures, we have new Try It! activities through- Try It! activity on action potentials out the book. These activities present data, usually from classic New link to online calculator for Nernst and GHK equations experiments, and ask the students to interpret the results. Topics Added discussion of resistance of extracellular fluid to discussion of resistance to current flow include Benjamin Franklin’s little-known experiment that helped development of the phospholipid bilayer model of the membrane, Added space constant discussion and the experiments that resulted in oral rehydration therapy for Chapter 9 The Central Nervous System treating cholera. Added lateral sulcus, insula, cerebral aqueduct Re-classification of stages of sleep HIGHLIGHTS OF CONTENT UPDATES Pericytes in blood-brain barrier formation Chapter 1 Introduction to Physiology Dopaminergic pathways and addiction New Focus on Graphing with a new Try It! activity Chapter 10 Sensory Physiology Added information on the connectome and microbiome New Try It! activity on sweet and salty taste Updated information on literature searches and citations Additional information on non-neural sensors and Merkel cells Chapter 2 Molecular Interactions Four new element names in the periodic table, inside the Chapter 11 Efferent Division: Autonomic and Somatic Motor Control back cover of the text Added ribbon diagram/Richardson diagram of proteins Expanded table on properties of autonomic neurotransmitter receptors Chapter 3 Compartmentation: Cells and Tissues Added NN and NM nicotinic subtypes Explanations of light and electron microscopy Added discussion of sarin nerve gas New Emerging Concepts box on induced pluripotent stem Updated anti-nicotine vaccine cells (iPSs) Etiology of diabetic neuropathy Chapter 5 Membrane Dynamics Chapter 12 Muscles New Try It! activity on lipid bilayers Expanded discussion of myosin light chains in striated Three Phys in Action video references in Figures 5.4, 5.6, muscle and 5.23 New table with autonomic effects on smooth muscles vii A01_SILV5197_08_SE_FM.indd 7 12/14/17 12:39 AM  viii FM/BM TITLE Chapter 13 Integrative Physiology I: Control of Body Chapter 20 Integrative Physiology II: Fluid and Movement Electrolyte Balance Addition information on reflexes and muscle tone New section on role of kidney in hypertension Updated Parkinson’s treatments New Concept Check question Expanded tetanus Running Problem Expanded discussion of K+ handling Added zona gomerulosa, paraventricular and supraoptic nuclei Chapter 14 Cardiovascular Physiology New section on endocrine pathologies in fluid balance New Running problem on atypical presentation of myocar- New Level 3 Review question on Liddle’s syndrome dial infarction in a woman Chapter 21 The Digestive System New section and new figure on coronary circulation New Try It! activity on Starling’s law of the heart New Try It! activity on role of the SGLT in treating diarrhea Added discussion of echocardiography New information on cholera vaccine Expanded ejection fraction discussion Updated discussion on microfold cells New discussion of ion channel subtypes Added guanylate cyclase-C (GC-C), uroguanylin and guanylin, plecanatide Chapter 15 Blood Flow and the Control of Blood Pressure Chapter 22 Metabolism and Energy Balance Updated information on pericytes and their functions New discussion of blood-retinal barrier Updated model for appetite Updated discussion of angiogenesis including angiopoietin Updated pharmacological trials for anorexia Latent autoimmune diabetes; also called type 1.5; gestational and angiopoietin/Tie signaling pathway. New Review quantitative question on Bernoulli’s principle diabetes (GDM); MODY, maturity-onset diabetes of the young. Added mechanism of action of metformin of fluid flow New sections on coronary blood flow and cerebral Added cardiovascular risk calculator link blood flow Chapter 23 Endocrine Control of Growth and Metabolism Updated statistics on CV diseases Expanded discussion of melanocortins and their receptors Added neurogenic shock in the control of food intake. Chapter 16 Blood Agouti-related protein (AGRP), MC4R receptors Revised art, includes Figures 16.2, 16.4, 16.6, and 16.7 Added explanation of the role of ghrelin in growth hormone release Updated information on treatment for sickle cell disease New figure for feedback control of growth hormone release Chapter 17 Mechanics of Breathing Updated discussion on off-label use of growth hormone in adults Forced vital capacity test Primary cilia in chrondrocytes and osteocytes act as FEV1 /FVC ratio mechnotransducers New figure and Figure Question for forced vital capacity test Role of calcium-sensing receptor and NALCN channel in Antenatal corticosteroids to prevent NRDS neuronal excitability Chapter 18 Gas Exchange and Transport New figure and discussion of intestinal and renal Ca2 + transport Updated information on action of carbonic anhydrase Skeletal deformaties in ciliopathies Updated information on hemoglobin-based blood substitutes New figure and discussion of bone remodeling, including Carotid body plasticity in disease states RANK, RANKL, osteoprotegerin, osteoid Chapter 19 The Kidneys New Review question on osteopetrosis New map for factors influencing GFR Chapter 24 The Immune System Updated model of organic anion transport, including 6 NEW figures. Most art significantly revised. OAT family transporters Added concepts include long-lived plasma cells, mucosa- New figure and table on renal handling of some common associated lymphoid tissue (MALT), self-antigens, negative substances selection, hygiene hypothesis, Zika virus, DAMPS – danger- New Try It! activity on glucosuria and the discovery of associated molecular patterns, B cell receptors, regulatory T insulin cells (Tregs) PAH clearance and calculation of renal plasma f low Updated information on IgD, contact-dependent signaling discussion New term: renal handling Chapter 26 Reproduction and Development New Figure Question Kisspeptin control of GNRH and role in puberty Updated glomerular filtration barrier to include glomerular Origin of the acrosome capillary glycocalyx, slit diaphragm Flibanserin for low libido in women A01_SILV5197_08_SE_FM.indd 8 12/14/17 12:39 AM  ACKNOWLEDGMENTS Writing, editing, and publishing a textbook is a group project that David Kurjiaka, Grand Valley State University requires the talent and expertise of many people. No one scientist Mary Jane Niles, University of San Francisco has the detailed background needed in all areas to write a book of Rudy M. Ortiz, University of California, Merced this scope, and I am indebted to all my colleagues who so gener- Jennifer Rogers, University of Iowa ously share their expertise in each edition. I particularly want to Jia Sun, Imperial Valley College acknowledge Bruce Johnson, Cornell University, Department of Alan Sved, University of Pittsburgh Neurobiology and Behavior, a superb neurobiologist and educa- Many other instructors and students took time to write or tor, who once again ensured that the chapters on neurobiology are e-mail queries or suggestions for clarification, for which I thank accurate and reflect the latest developments in that rapidly chang- them. I am always delighted to have input, and I apologize that I ing field. I would also like to thank Michael Chirillo, a former do not have room to acknowledge them all individually. graduate teaching assistant of mine, for his work developing the Try It! features in between interviewing for and starting a medical residency program. Peter English, a colleague and former student, Specialty Reviews has also joined the team helping with this revision. No one can be an expert in every area of physiology, and I am A huge thank you goes to immunologists Natalie Steinel, from deeply thankful for my friends and colleagues who reviewed entire UT-Austin Dell Medical School, and Tynan A. Becker, from Uni- chapters or answered specific questions. Even with their help, there versity of Alaska, for their assistance and critical review of the may be errors, for which I take full responsibility. The specialty Chapter 24 revision. Brian Sumner, a 3rd year medical student reviewers for this edition were: at the George Washington University School of Medicine, gra- Natalie Steinel, UT-Austin Dell Medical School ciously volunteered time out of his busy clinical rotations to read Tynan A. Becker, University of Alaska the revised chapter and ensure that it was student-friendly. The art team of Bill Ober, M.D. and Claire Ober, R.N. has Photographs worked with me since the first edition, and I am always grateful for their scientifically astute suggestions and revisions. They were I would like to thank Kristen Harris, University of Texas who joined in the last edition by Anita Impagliazzo, who brought a generously provided micrographs from her research. fresh eye and new figure ideas. Instructors and students often contact me directly about the Supplements book, and for this edition I would particularly like to thank Allison Damian Hill once again worked with me to revise and improve the Brekke, James Mayer, and Dean A. Wiseman for comments and Instructor Resource Manual that accompanies the book. I believe suggestions. Thanks also to my students who keep me informed that supplements should reflect the style and approach of the text, of the typos that creep in no matter how many people look at the so I am grateful that Damian has continued to be my alter-ego for manuscript and pages. so many editions. Peter English is helping with Mastering activities Many other people devoted their time and energy to making this revision. this book a reality, and I would like to thank them all, collectively I would also like to thank my colleagues who helped with the and individually. I apologize in advance to anyone whose name I test bank and media supplements for this edition: have omitted. Heidi Bustamante, University of Colorado, Boulder Chad M. Wayne, University of Houston Reviewers Margaret Flemming, Austin Community College I am particularly grateful to the instructors who reviewed one or Cheryl Neudauer, Minneapolis Community & Technical more chapters of the last edition. There were many suggestions in College their thoughtful reviews that I was unable to include in the text, but I appreciate the time and thought that went into their comments. The Development and Production Team The reviewers for this edition include: Writing a manuscript is only a first step in the long and compli- Jake Brashears, San Diego City College cated process that results in a bound book with all its ancillaries. Trevor Cardinal, California Polytechnic State University The team that works with me on book development deserves a lot Michael S. Finkler, Indiana University Kokomo of credit for the finished product. Gary Hespenheide designed a Victor Fomin, University of Delaware bright and cheerful cover that continues our tradition of images Jill Gifford, Youngstown State University that show science as art. Anne A. Reid, my long-time developmental ix A01_SILV5197_08_SE_FM.indd 9 12/14/17 12:39 AM  x ACKNOWLEDGMENTS editor, is always wonderful to work with, and provides thoughtful Justin Trombold, Ph.D. suggestions that improve what I wrote. Kurt Venator, Ph.D. The team at Pearson Education worked tirelessly to see this Kira Wenstrom, Ph.D. edition move from manuscript to bound book. My acquisitions Finally, special thanks to my colleagues in the American editor, Kelsey Volker Churchman, was joined by Lauren Harp, Physiological Society, the Human Anatomy & Physiology Soci- Senior Acquisitions Editor for the second part of this revision. Ash- ety, and the International Union of Physiological Sciences ley Williams and Kate Abderholden, assistant editors, kept track whose experiences in the classroom have enriched my own of everyone and everything for us. Chriscelle Palaganas, Program understanding of how to teach physiology. I would also like to Manager, provided excellent guidance and support throughout the recognize a special group of friends for their continuing sup- whole production process. port: Penelope Hansen (Memorial University, St. John’s), Mary The task of coordinating production fell to Pearson Content Anne Rokitka (SUNY Buffalo), Rob Carroll (East Carolina Producer Deepti Agarwal. Nathaniel Jones handled composi- University School of Medicine), Cindy Gill (Hampshire tion and project management, and Project Manager Stephanie College), and Joel Michael (Rush Medical College), as well as Marquez at the art house, Imagineering, managed the team that Ruth Buskirk, Jeanne Lagowski, Jan M. Machart and Marilla prepared the art for production. Katrina Mohn was the photo Svinicki (University of Texas). researcher who found the wonderful new photos that appear in As always, I thank my family and friends for their patience, this edition. Nicole Constantine was the assistant media producer understanding, and support during the chaos that seems inevitable who kept my supplements authors on task and on schedule. Wendy with book revisions. The biggest thank you goes to my husband Mears is the product marketing manager who works with the Andy, whose love, support, and willingness to forgo home-cooked excellent sales teams at Pearson Education and Pearson Interna- meals on occasion help me meet my deadlines. tional, and Derek Perrigo is the Field Marketing Manager for the anatomy and physiology list. A Work in Progress Special Thanks One of the most rewarding aspects of writing a textbook is the As always, I would like to thank my students and colleagues who opportunity it has given me to meet or communicate with other looked for errors and areas that needed improvement. I’ve learned instructors and students. In the 20 years since the first edition was that awarding one point of extra credit for being the first student published, I have heard from people around the world and have to report a typo works really well. My graduate teaching assistants had the pleasure of hearing how the book has been incorporated over the years have all played a huge role in my teaching, and their into their teaching and learning. input has helped shape how I teach. Many of them are now faculty Because science textbooks are revised every 3 or 4 years, they members themselves. They include: are always works in progress. I invite you to contact me or my publisher with any suggestions, corrections, or comments about Ari Berman, Ph.D. this edition. I am most reachable through e-mail at silverthorn@ Lawrence Brewer, Ph.D. utexas.edu. You can reach my editor at the following address: Kevin Christmas, Ph.D. Michael Chirillo, M.D., Ph.D. Applied Sciences Lynn Cialdella Kam, M.S., M.B.A., Ph.D. Pearson Education Sarah Davies Kanke, Ph.D. 1301 Sansome Street Peter English, Ph.D. San Francisco, CA 94111 Carol C. Linder, Ph.D. Karina Loyo-Garcia, Ph.D. Dee U. Silverthorn Jan M. Machart, Ph.D. [email protected] Tonya Thompson, M.D. University of Texas Patti Thorn, Ph.D. Austin, Texas A01_SILV5197_08_SE_FM.indd 10 12/14/17 12:39 AM  CONTENTS UNIT 1 Basic Cell Processes: Integration and Coordination CHAPTER 1 CHAPTER 2 Introduction to Physiology 1 Molecular Interactions 28 Physiology Is an Integrative Science 2 RUNNING PROBLEM Chromium Supplements 29 RUNNING PROBLEM What to Believe? 2 Molecules and Bonds 29 EMERGING CONCEPTS The Changing World of Omics 3 Most Biomolecules Contain Carbon, Hydrogen, and Oxygen 29 Function and Mechanism 4 Electrons Have Four Important Biological Roles 33 Themes in Physiology 5 Covalent Bonds between Atoms Create Molecules 33 FOCUS ON... Mapping 6 Noncovalent Bonds Facilitate Reversible Interactions 39 Theme 1: Structure and Function Are Closely Noncovalent Interactions 40 Related 8 Hydrophilic Interactions Create Biological Solutions 40 Theme 2: Living Organisms Need Energy 8 Molecular Shape Is Related to Molecular Function 40 Theme 3: Information Flow Coordinates Body Functions 9 Hydrogen Ions in Solution Can Alter Molecular Shape 41 Theme 4: Homeostasis Maintains Internal Protein Interactions 46 Stability 9 Proteins Are Selective about the Molecules They Bind 46 Homeostasis 9 Protein-Binding Reactions Are Reversible 47 What Is the Body’s Internal Environment? 10 Binding Reactions Obey the Law of Mass Action 47 Homeostasis Depends on Mass Balance 10 The Dissociation Constant Indicates Affinity 48 Excretion Clears Substances from the Body 12 Multiple Factors Alter Protein Binding 48 Homeostasis Does Not Mean Equilibrium 13 The Body Regulates the Amount of Protein in Cells 51 Control Systems and Homeostasis 13 Reaction Rate Can Reach a Maximum 51 Local Control Is Restricted to a Tissue 13 CHAPTER SUMMARY 55 | REVIEW QUESTIONS 56 Reflex Control Uses Long-Distance Signaling 14 Response Loops Begin with a Stimulus 14 Feedback Loops Modulate the Response Loop 15 CHAPTER 3 Negative Feedback Loops Are Homeostatic 15 Compartmentation: Cells and Tissues 58 Positive Feedback Loops Are Not Homeostatic 16 Functional Compartments of the Body 59 Feedforward Control Allows the Body to Anticipate RUNNING PROBLEM Pap Tests Save Lives 59 Change 17 The Lumens of Some Organs Are Outside the Body 59 Biological Rhythms Result from Changes in a Setpoint 17 Functionally, the Body Has Three Fluid Compartments 61 The Science of Physiology 18 Biological Membranes 61 Good Scientific Experiments Must Be Carefully The Cell Membrane Separates Cell from Environment 61 Designed 18 Membranes Are Mostly Lipid and Protein 61 FOCUS ON... Graphing 20 Membrane Lipids Create a Hydrophobic Barrier 62 The Results of Human Experiments Can Be Difficult to Membrane Proteins May Be Loosely or Tightly Bound to the Interpret 22 Membrane 62 Membrane Carbohydrates Attach to Both Lipids and CHAPTER SUMMARY 25 | REVIEW QUESTIONS 26 Proteins 64 xi A01_SILV5197_08_SE_FM.indd 11 12/14/17 12:39 AM  xii CONTENTS Intracellular Compartments 64 Enzymes 98 Cells Are Divided into Compartments 65 Enzymes Are Proteins 99 The Cytoplasm Includes Cytosol, Inclusions, Fibers, Reaction Rates Are Variable 99 and Organelles 65 Enzymes May Be Activated, Inactivated, or Inclusions Are in Direct Contact with the Cytosol 65 Modulated 99 Cytoplasmic Protein Fibers Come in Three Sizes 68 Enzymes Lower Activation Energy of Microtubules Form Centrioles, Cilia, and Flagella 68 Reactions 100 EMERGING CONCEPTS Single Cilia Are Sensors 68 Enzymatic Reactions Can Be Categorized 101 The Cytoskeleton Is a Changeable Scaffold 68 Metabolism 102 Motor Proteins Create Movement 69 Cells Regulate Their Metabolic Pathways 102 Organelles Create Compartments for Specialized Functions 70 Catabolic Pathways Produce ATP 104 The Nucleus Is the Cell’s Control Center 71 One Glucose Molecule Can Yield 30–32 ATP 109 Tissues of the Body 73 Anaerobic Metabolism Makes Two ATP 109 Extracellular Matrix Has Many Functions 73 Proteins Are the Key to Cell Function 110 Cell Junctions Hold Cells Together to Form Tissues 73 DNA Guides the Synthesis of RNA 113 Epithelia Provide Protection and Regulate Exchange 75 Alternative Splicing Creates Multiple Proteins from One DNA Sequence 114 Connective Tissues Provide Support and Barriers 80 mRNA Translation Links Amino Acids 114 Muscle and Neural Tissues Are Excitable 82 EMERGING CONCEPTS Purple Petunias and Tissue Remodeling 84 RNAi 114 Apoptosis Is a Tidy Form of Cell Death 84 Protein Sorting Directs Proteins to Their Stem Cells Can Create New Specialized Cells 85 Destination 115 EMERGING CONCEPTS Induced Pluripotent Stems Proteins Undergo Posttranslational Cells 85 Modification 115 FOCUS ON... The Skin 86 CHAPTER SUMMARY 118 | REVIEW QUESTIONS 119 Organs 87 CHAPTER SUMMARY 88 | REVIEW QUESTIONS 90 CHAPTER 5 Membrane Dynamics 121 CHAPTER 4 Energy and Cellular Metabolism 92 RUNNING PROBLEM Cystic Fibrosis 122 Homeostasis Does Not Mean Equilibrium 122 RUNNING PROBLEM Tay-Sachs Disease: A Deadly Inheritance 93 Osmosis and Tonicity 124 Energy in Biological Systems 93 The Body Is Mostly Water 124 Energy Is Used to Perform Work 94 The Body Is in Osmotic Equilibrium 124 Energy Comes in Two Forms: Kinetic and Potential 94 Osmolarity Describes the Number of Particles in Solution 125 Energy Can Be Converted from One Form to Another 95 Tonicity Describes the Volume Change of a Cell 126 Thermodynamics Is the Study of Energy Use 95 Chemical Reactions 96 Transport Processes 131 Cell Membranes Are Selectively Permeable 131 Energy Is Transferred between Molecules during Reactions 96 Diffusion 132 Activation Energy Gets Reactions Started 96 Lipophilic Molecules Cross Membranes by Simple Energy Is Trapped or Released during Reactions 96 Diffusion 134 Net Free Energy Change Determines Reaction Protein-Mediated Transport 136 Reversibility 98 Membrane Proteins Have Four Major Functions 136 A01_SILV5197_08_SE_FM.indd 12 12/21/17 6:28 PM  CONTENTS xiii Channel Proteins Form Open, Water-Filled Long-Distance Communication May Be Electrical or Passageways 138 Chemical 167 Carrier Proteins Change Conformation to Move Cytokines May Act as Both Local and Long-Distance Molecules 139 Signals 167 Facilitated Diffusion Uses Carrier Proteins 141 Signal Pathways 168 Active Transport Moves Substances against Their Receptor Proteins Are Located Inside the Cell or on the Concentration Gradients 142 Cell Membrane 168 Carrier-Mediated Transport Exhibits Specificity, Competition, Membrane Proteins Facilitate Signal and Saturation 144 Transduction 170 Vesicular Transport 146 The Most Rapid Signal Pathways Change Ion Flow through Phagocytosis Creates Vesicles Using the Channels 171 Cytoskeleton 146 Most Signal Transduction Uses G Proteins 173 Endocytosis Creates Smaller Vesicles 147 Many Lipophobic Hormones Use GPCR-cAMP CLINICAL FOCUS LDL: The Lethal Lipoprotein 147 Pathways 173 Exocytosis Releases Molecules Too Large for Transport G Protein-Coupled Receptors Also Use Lipid-Derived Proteins 147 Second Messengers 173 Epithelial Transport 149 Catalytic Receptors Have Enzyme Activity 175 Epithelial Transport May Be Paracellular or Integrin Receptors Transfer Information from the Extracellular Transcellular 149 Matrix 175 Transcellular Transport of Glucose Uses Membrane Novel Signal Molecules 175 Proteins 150 Calcium Is an Important Intracellular Signal 176 Transcytosis Uses Vesicles to Cross an Epithelium 151 Gases Are Ephemeral Signal Molecules 177 The Resting Membrane Potential 152 BIOTECHNOLOGY Calcium Signals Glow in the Electricity Review 152 Dark 177 The Cell Membrane Enables Separation of Electrical Charge in CLINICAL FOCUS From Dynamite to the Body 152 Medicine 178 All Living Cells Have a Membrane Potential 153 Some Lipids Are Important Paracrine Signals 178 The Resting Membrane Potential Is Due Mostly to Potassium 156 Modulation of Signal Pathways 179 Changes in Ion Permeability Change the Membrane Receptors Exhibit Saturation, Specificity, and Potential 157 Competition 179 Integrated Membrane Processes: Insulin One Ligand May Have Multiple Receptors 179 Secretion 158 Up and Down-Regulation Enable Cells to Modulate Responses 180 CHAPTER SUMMARY 160 | REVIEW QUESTIONS 161 Cells Must Be Able to Terminate Signal Pathways 181 Many Diseases and Drugs Target the Proteins of Signal CHAPTER 6 Transduction 181 Communication, Integration, Homeostatic Reflex Pathways 181 and Homeostasis 164 Cannon’s Postulates Describe Regulated Variables and Control Systems 182 RUNNING PROBLEM Diabetes Mellitus: A Growing Long-Distance Pathways Maintain Epidemic 165 Homeostasis 182 Cell-to-Cell Communication 165 Control Systems Vary in Their Speed and Gap Junctions Create Cytoplasmic Bridges 165 Specificity 186 Contact-Dependent Signals Require Cell-to-Cell Complex Reflex Control Pathways Have Several Integrating Contact 165 Centers 188 Local Communication Uses Paracrine and Autocrine CHAPTER SUMMARY 191 | REVIEW QUESTIONS 192 Signals 167 A01_SILV5197_08_SE_FM.indd 13 12/21/17 6:28 PM  xiv CONTENTS UNIT 2 Homeostasis and Control CHAPTER 7 Receptor or Second Messenger Problems Cause Abnormal Tissue Responsiveness 215 Introduction to the Endocrine System 194 Diagnosis of Endocrine Pathologies Depends on the Com- Hormones 195 plexity of the Reflex 215 RUNNING PROBLEM Graves’ Disease 195 Hormone Evolution 217 Hormones Have Been Known Since Ancient FOCUS ON... The Pineal Gland 218 Times 195 CHAPTER SUMMARY 220 | REVIEW QUESTIONS 221 CLINICAL FOCUS Diabetes: The Discovery of Insulin 196 What Makes a Chemical a Hormone? 196 Hormones Act by Binding to Receptors 197 CHAPTER 8 Hormone Action Must Be Terminated 197 Neurons: Cellular and Network Properties 223 The Classification of Hormones 199 RUNNING PROBLEM Mysterious Paralysis 224 Most Hormones Are Peptides or Proteins 199 Organization of the Nervous System 224 Steroid Hormones Are Derived from Cells of the Nervous System 226 Cholesterol 200 Neurons Carry Electrical Signals 226 Some Hormones Are Derived from Single Amino Acids 202 Establishing Synapses Depends on Chemical Signals 229 Control of Hormone Release 205 Glial Cells Provide Support for Neurons 231 The Endocrine Cell Is the Sensor in Simple Endocrine Can Stem Cells Repair Damaged Neurons? 233 Reflexes 205 Electrical Signals in Neurons 234 Many Endocrine Reflexes Involve the Nervous The Nernst Equation Predicts Membrane Potential for a System 205 Single Ion 234 Neurohormones Are Secreted into the Blood by The GHK Equation Predicts Membrane Potential Using Mul- Neurons 205 tiple Ions 234 The Pituitary Gland Is Actually Two Fused Glands 205 Ion Movement Creates Electrical Signals 235 The Posterior Pituitary Stores and Releases Two Gated Channels Control the Ion Permeability of the Neurohormones 207 Neuron 235 The Anterior Pituitary Secretes Six Hormones 207 CLINICAL FOCUS Mutant Channels 236 A Portal System Connects the Hypothalamus and Anterior Current Flow Obeys Ohm’s Law 236 Pituitary 209 Graded Potentials Reflect Stimulus Strength 237 Anterior Pituitary Hormones Control Growth, Metabolism, Action Potentials Travel Long Distances 239 and Reproduction 209 Feedback Loops Are Different in the Hypothalamic-Pituitary Na+ and K+ Move across the Membrane during Action Pathway 211 Potentials 240 Hormone Interactions 212 One Action Potential Does Not Alter Ion Concentration Gradients 242 In Synergism, the Effect of Interacting Hormones Is More than Additive 213 Axonal Na + Channels Have Two Gates 242 A Permissive Hormone Allows Another Hormone to Exert Its Action Potentials Will Not Fire during the Absolute Refractory Full Effect 213 Period 243 Antagonistic Hormones Have Opposing Effects 213 Action Potentials Are Conducted 245 Endocrine Pathologies 214 Larger Neurons Conduct Action Potentials Faster 245 Hypersecretion Exaggerates a Hormone’s Effects 214 Conduction Is Faster in Myelinated Axons 247 Hyposecretion Diminishes or Eliminates a Hormone’s Chemical Factors Alter Electrical Activity 249 Effects 215 BIOTECHNOLOGY The Body’s Wiring 249 A01_SILV5197_08_SE_FM.indd 14 12/21/17 6:28 PM  CONTENTS xv Cell-To-Cell Communication in the Nervous System 249 The Behavioral State System Modulates Motor Output 292 Neurons Communicate at Synapses 249 Why Do We Sleep? 292 Neurons Secrete Chemical Signals 250 EMERGING CONCEPTS Brain Glymphatics 294 Neurotransmitters Are Highly Varied 251 Physiological Functions Exhibit Circadian Rhythms 295 CLINICAL FOCUS Myasthenia Gravis 253 Emotion and Motivation Involve Complex Neural BIOTECHNOLOGY Of Snakes, Snails, Spiders, and Sushi 254 Pathways 296 Neurotransmitters Are Released from Vesicles 254 Moods Are Long-Lasting Emotional States 297 Stronger Stimuli Release More Neurotransmitter 257 Learning and Memory Change Synaptic Connections in the Brain 297 Integration of Neural Information Transfer 258 Learning Is the Acquisition of Knowledge 298 Postsynaptic Responses May Be Slow or Fast 258 Memory Is the Ability to Retain and Recall Information 298 Pathways Integrate Information from Multiple Neurons 261 Language Is the Most Elaborate Cognitive Behavior 300 Synaptic Activity Can Be Modified 261 Personality Is a Combination of Experience and Long-Term Potentiation Alters Synapses 264 Inheritance 301 Disorders of Synaptic Transmission Are Responsible for Many Diseases 264 CHAPTER SUMMARY 303 | REVIEW QUESTIONS 305 CHAPTER SUMMARY 266 | REVIEW QUESTIONS 268 CHAPTER 10 CHAPTER 9 Sensory Physiology 307 The Central Nervous System 271 RUNNING PROBLEM Ménière’s Disease 308 General Properties of Sensory Systems 308 Emergent Properties of Neural Networks 272 Receptors Are Sensitive to Particular Forms of Energy 309 RUNNING PROBLEM Infantile Spasms 272 Sensory Transduction Converts Stimuli into Graded Evolution of Nervous Systems 272 Potentials 310 Anatomy of the Central Nervous System 274 A Sensory Neuron Has a Receptive Field 310 The CNS Develops from a Hollow Tube 274 The CNS Integrates Sensory Information 310 The CNS Is Divided into Gray Matter and White Matter 274 Coding and Processing Distinguish Stimulus Properties 312 Bone and Connective Tissue Support the CNS 277 Somatic Senses 315 The Brain Floats in Cerebrospinal Fluid 277 Pathways for Somatic Perception Project to the Cortex and The Blood-Brain Barrier Protects the Brain 279 Cerebellum 315 Neural Tissue Has Special Metabolic Requirements 280 Touch Receptors Respond to Many Different Stimuli 317 CLINICAL FOCUS Diabetes: Hypoglycemia and the Brain 281 Skin Temperature Receptors Are Free Nerve Endings 318 The Spinal Cord 281 Nociceptors Initiate Protective Responses 318 The Brain 282 CLINICAL FOCUS Natural Painkillers 320 The Brain Stem Is the Oldest Part of the Brain 283 Chemoreception: Smell and Taste 322 The Cerebellum Coordinates Movement 285 Olfaction Is One of the Oldest Senses 322 The Diencephalon Contains the Centers for Homeostasis 285 Taste Is a Combination of Five Basic Sensations 324 The Cerebrum Is the Site of Higher Brain Functions 287 Taste Transduction Uses Receptors and Channels 325 Brain Function 288 The Ear: Hearing 328 The Cerebral Cortex Is Organized into Functional Areas 289 Hearing Is Our Perception of Sound 329 The Spinal Cord and Brain Integrate Sensory Sound Transduction Is a Multistep Process 329 Information 290 The Cochlea Is Filled with Fluid 330 Sensory Information Is Processed into Perception 291 Sounds Are Processed First in the Cochlea 333 The Motor System Governs Output from the CNS 291 Auditory Pathways Project to the Auditory Cortex 333 A01_SILV5197_08_SE_FM.indd 15 12/21/17 6:28 PM  xvi CONTENTS Hearing Loss May Result from Mechanical or Neural Summary of Sympathetic and Parasympathetic Damage 334 Branches 367 The Ear: Equilibrium 335 The Somatic Motor Division 368 The Vestibular Apparatus Provides Information about Move- A Somatic Motor Pathway Consists of One Neuron 368 ment and Position 335 The Neuromuscular Junction Contains Nicotinic The Semicircular Canals Sense Rotational Acceleration 335 Receptors 370 The Otolith Organs Sense Linear Acceleration and Head CHAPTER SUMMARY 371 | REVIEW QUESTIONS 372 Position 337 Equilibrium Pathways Project Primarily to the Cerebellum 337 The Eye and Vision 338 CHAPTER 12 The Skull Protects the Eye 338 Muscles 374 Light Enters the Eye through the Cornea 339 RUNNING PROBLEM Periodic Paralysis 375 The Lens Focuses Light on the Retina 341 Skeletal Muscle 376 Phototransduction Occurs at the Retina 343 Skeletal Muscles Are Composed of Muscle Fibers 376 EMERGING CONCEPTS Melanopsin 344 Myofibrils Are Muscle Fiber Contractile Structures 377 Photoreceptors Transduce Light into Electrical Signals 344 Muscle Contraction Creates Force 380 Signal Processing Begins in the Retina 347 Actin and Myosin Slide Past Each Other during Contraction 382 CHAPTER SUMMARY 352 | REVIEW QUESTIONS 353 Myosin Crossbridges Move Actin Filaments 383 Calcium Signals Initiate Contraction 383 Myosin Heads Step along Actin Filaments 384 CHAPTER 11 Acetylcholine Initiates Excitation-Contraction Coupling 385 Efferent Division: Autonomic and Somatic BIOTECHNOLOGY Watching Myosin Work 385 Motor Control 355 Skeletal Muscle Contraction Requires a Steady Supply of ATP 388 RUNNING PROBLEM A Powerful Addiction 356 Fatigue Has Multiple Causes 389 The Autonomic Division 356 Skeletal Muscle Is Classified by Speed and Fatigue Autonomic Reflexes Are Important for Homeostasis 357 Resistance 390 Antagonistic Control Is a Hallmark of the Autonomic Resting Fiber Length Affects Tension 392 Division 358 Force of Contraction Increases with Summation 393 Autonomic Pathways Have Two Efferent Neurons in A Motor Unit Is One Motor Neuron and Its Muscle Series 358 Fibers 393 Sympathetic and Para