Seeley's Essentials of Anatomy & Physiology Eleventh Edition PDF

 Page i ELEVENTH EDITION Seeley’s Essentials of Anatomy & Physiology Cinnamon VanPutte SIU SCHOOL OF DENTAL MEDICINE Jennifer Regan UNIVERSITY OF SOUTHERN MISSISSIPPI Andrew Russo...

 Page i ELEVENTH EDITION Seeley’s Essentials of Anatomy & Physiology Cinnamon VanPutte SIU SCHOOL OF DENTAL MEDICINE Jennifer Regan UNIVERSITY OF SOUTHERN MISSISSIPPI Andrew Russo UNIVERSITY OF IOWA  Page ii SEELEY’S ESSENTIALS OF ANATOMY & PHYSIOLOGY, ELEVENTH EDITION Published by McGraw Hill LLC, 1325 Avenue of the Americas, New York, NY 10121. Copyright © by McGraw Hill LLC. All rights reserved. Printed in the United States of America. No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written consent of McGraw Hill LLC, including, but not limited to, in any network or other electronic storage or transmission, or broadcast for distance learning. Some ancillaries, including electronic and print components, may not be available to customers outside the United States. This book is printed on acid-free paper. 1 2 3 4 5 6 7 8 9 LWI 24 23 22 21 ISBN 978-1-265-34844-1 MHID 1-265-34844-8 Cover Image: Olga Danylenko/Shutterstock All credits appearing on page are considered to be an extension of the copyright page. The Internet addresses listed in the text were accurate at the time of publication. The inclusion of a website does not indicate an endorsement by the authors or McGraw Hill LLC, and McGraw Hill LLC does not guarantee the accuracy of the information presented at these sites. mheducation.com/highered  Page iii DEDICATION This text is dedicated to our families. Without their uncompromising support and love, this effort would not have been possible. Our spouses and children have been more than patient while we’ve spent many nights at the computer surrounded by mountains of books. We also want to acknowledge and dedicate this edition to the previous authors as we continue the standard of excellence that they have set for so many years. For each of us, authoring this text is a culmination of our passion for teaching and represents an opportunity to pass knowledge on to students beyond our own classrooms; this has all been made possible by the support and mentorship we in turn have received from our teachers, colleagues, friends, and family.  Page iv Brief Contents Chapter 0 How to Be Successful in A&P Chapter 1 The Human Organism Chapter 2 The Chemical Basis of Life Chapter 3 Cell Structures and Their Functions Chapter 4 Tissues Chapter 5 Integumentary System Chapter 6 Skeletal System: Bones and Joints Chapter 7 Muscular System Chapter 8 Nervous System Chapter 9 Senses Chapter 10 Endocrine System Chapter 11 Blood Chapter 12 Heart Chapter 13 Blood Vessels and Circulation Chapter 14 Lymphatic System and Immunity Chapter 15 Respiratory System Chapter 16 Digestive System Chapter 17 Nutrition, Metabolism, and Body Temperature Regulation Chapter 18 Urinary System and Fluid Balance Chapter 19 Reproductive System Chapter 20 Development, Heredity, and Aging Appendices A Table of Measurements B Some Reference Laboratory Values C Answers to Process Figure Questions D Answers to Odd-Numbered Critical Thinking Questions E Answers to Odd-Numbered Apply It Questions F Selected Abbreviations  Page v Contents About the Authors Preface Chapter-by-Chapter Changes List of Clinical Impact Essays Acknowledgments Chapter 00 How to Be Successful in A&P 0.1 The World of A&P 0.2 Developing Critical Thinking Skills 0.3 Five Metacognitive Learning Strategies 0.4 Using the Five Metacognitive Learning Strategies with This Textbook 0.5 Textbook Features and Figure Colors and Symbols Chapter 1 The Human Organism 1.1 Anatomy and Physiology 1.2 Structural and Functional Organization of the Human Body 1.3 Characteristics of Life 1.4 Homeostasis 1.5 Terminology and the Body Plan Chapter 2 The Chemical Basis of Life 2.1 Basic Chemistry 2.2 Chemical Reactions and Energy 2.3 Acids and Bases 2.4 Inorganic Molecules 2.5 Organic molecules Chapter 3 Cell Structures and Their Functions 3.1 Cell Structure 3.2 Functions of the Cell 3.3 Cell Membrane 3.4 Movement Through the Cell Membrane 3.5 Organelles 3.6 Whole-Cell Activity Chapter 4 Tissues 4.1 Tissues and Histology 4.2 Epithelial Tissue 4.3 Connective Tissue 4.4 Muscle Tissue 4.5 Nervous Tissue 4.6 tissue Membranes 4.7 Tissue Damage and Inflammation 4.8 Tissue Repair Chapter 5 Integumentary System 5.1 Functions of the Integumentary System 5.2 Skin 5.3 Subcutaneous TIssue 5.4 Accessory Skin Structures 5.5 Physiology of the Integumentary System 5.6 Integumentary System as a Diagnostic Aid 5.7 Burns Chapter 6 Skeletal System: Bones and Joints 6.1 Functions of the Skeletal System 6.2 Bone Histology 6.3 Bone Anatomy 6.4 Bone Development 6.5 Bone Growth 6.6 Bone Remodeling 6.7 Bone Repair 6.8 Calcium Homeostasis 6.9 Skeletal Anatomy Overview 6.10 Axial skeleton 6.11 Appendicular Skeleton 6.12 Joints Chapter 7 Muscular System 7.1 Functions of the Muscular System 7.2 General Properties of Muscle Tissue 7.3 Skeletal Muscle Anatomy 7.4 Skeletal Muscle Fiber Physiology 7.5 Whole Skeletal Muscle Physiology 7.6 Muscle Fiber Types 7.7 Energy Sources for Muscle Contraction 7.8 Smooth Muscle and Cardiac Muscle 7.9 General Principles of Skeletal Muscle Anatomy 7.10 Muscles of the Head and Neck 7.11 Trunk Muscles 7.12 Upper Limb Muscles 7.13 Lower Limb Muscles Chapter 8 Nervous System 8.1 Functions of the Nervous System 8.2 Divisions of the Nervous System 8.3 Cells of the Nervous System 8.4 Electrical Signals and Neural Pathways 8.5 Central and Peripheral Nervous Systems 8.6 Spinal Cord 8.7 Spinal Nerves 8.8 Brain 8.9 Sensory Functions 8.10 Somatic Motor Functions 8.11 Other Brain Functions 8.12 Meninges, Ventricles, and Cerebrospinal Fluid 8.13 Cranial Nerves 8.14 Autonomic Nervous System 8.15 Enteric Nervous System Chapter 9 Senses 9.1 Sensation 9.2 Sensory Receptors 9.3 General Senses 9.4 Special Senses 9.5 Olfaction 9.6 Taste 9.7 Vision 9.8 Hearing and Balance  Page vi Chapter 10 Endocrine System 10.1 Principles of Chemical Communication 10.2 Functions of the Endocrine System 10.3 Hormones 10.4 Control of Hormone Secretion 10.5 Hormone Receptors and Mechanisms of Action 10.6 Endocrine Glands and Their Hormones 10.7 Other Hormones Chapter 11 Blood 11.1 Functions of Blood 11.2 Composition of Blood 11.3 Plasma 11.4 Formed Elements 11.5 Preventing Blood Loss 11.6 Blood Grouping 11.7 Diagnostic Blood Tests Chapter 12 Heart 12.1 Functions of the Heart 12.2 Size, Form, and Location of the Heart 12.3 Anatomy of the Heart 12.4 Histology of the Heart 12.5 Stimulation of the Heart 12.6 Cardiac Cycle 12.7 Heart Sounds 12.8 Regulation of Heart Function Chapter 13 Blood Vessels and Circulation 13.1 Functions of the Circulatory System 13.2 General Features of Blood Vessel Structure 13.3 Blood Vessels of the Pulmonary Circulation 13.4 Blood Vessels of the Systemic Circulation: Arteries 13.5 Blood Vessels of the Systemic Circulation: Veins 13.6 Physiology of Circulation 13.7 Control of Blood Flow in Tissues 13.8 Regulation of Arterial Pressure Chapter 14 Lymphatic System and Immunity 14.1 Functions of the Lymphatic System 14.2 Anatomy of the Lymphatic System 14.3 Immunity 14.4 Innate Immunity 14.5 Adaptive Immunity 14.6 Acquired Immunity 14.7 Immunotherapy Chapter 15 Respiratory System 15.1 Anatomy of the Respiratory System 15.2 Functions of the Respiratory System 15.3 Structures and Histology of the Respiratory Tract 15.4 Behavior of Gases 15.5 Physiology of the Respiratory System 15.6 Oxygen and Carbon Dioxide Transport in the Blood 15.7 Regulation of Ventilat ion Chapter 16 Digestive System 16.1 Functions of the Digestive System 16.2 Anatomy and Histology of the Digestive System 16.3 Oral Cavity, Pharynx, and Esophagus 16.4 Stomach 16.5 Small Intestine 16.6 Liver and Pancreas 16.7 Large Intestine 16.8 Digestion, Absorption, and Transport Chapter 17 Nutrition, Metabolism, and Body Temperature Regulation 17.1 Nutrition 17.2 Metabolism 17.3 Body Temperature Regulation Chapter 18 Urinary System and Fluid Balance 18.1 Functions of the Urinary System 18.2 Anatomy of the Kidneys 18.3 Urine Production 18.4 Regulation of Urine Concentration and Volume 18.5 Urine Movement 18.6 Body Fluid Compartments 18.7 Regulation of Extracellular Fluid Composition 18.8 Regulation of Acid-Base Balance Chapter 19 Reproductive System 19.1 Functions of the Reproductive System 19.2 Formation of Gametes 19.3 Male Reproductive System 19.4 Physiology of Male Reproduction 19.5 Female Reproductive System 19.6 Physiology of Female Reproduction Chapter 20 Development, Heredity, and Aging 20.1 Prenatal Development 20.2 Parturition 20.3 The Newborn 20.4 Lactation 20.5 First Year Following Birth 20.6 Life Stages 20.7 Genetics Appendices A Table of Measurements B Some Reference Laboratory Values C Answers to Process Figure Questions D Answers to Odd-Numbered Critical Thinking Questions E Answers to Odd-Numbered Apply It Questions F Selected Abbreviations Glossary Index  Page vii About the Authors Courtesy of Leanna Rolla Courtesy of Bridget Reeves Courtesy of the University of Iowa Cinnamon L. VanPutte Jennifer L. Regan Andrew F. Russo Associate Professor of Applied Dental Assistant Teaching Professor Professor of Molecular Physiology and Medicine University of Southern Mississippi Biophysics Southern Illinois University School of University of Iowa Dental Medicine For over twenty years, Jennifer has taught introductory biology, human anatomy and Andrew has over 20 years of classroom Cinnamon has been teaching biology and physiology, and genetics at the university experience with human physiology, human anatomy and physiology for over two and community college level. She has neurobiology, molecular biology, and cell decades. At SIU School of Dental Medicine received the Instructor of the Year Award at biology courses at the University of Iowa. He she teaches first year dental students and both the departmental and college level while is a recipient of the Collegiate Teaching participates in dental-based physiology teaching at USM. In addition, she has been Award and the J. P. Long Teaching Award in research. Cinnamon is an active member of recognized for her dedication to teaching by Basic Sciences. He is currently the course several professional societies, including the student organizations such as the Alliance director for a new medical school course Human Anatomy & Physiology Society for Graduate Education in Mississippi and called Mechanisms of Health and Disease (HAPS). Her Ph.D. in zoology, with an Increasing Minority Access to Graduate that integrates physiology, histology, and emphasis in endocrinology, is from Texas Education. Jennifer has dedicated much of genetics. He is a member of several A&M University. She worked in Dr. Duncan her career to improving lecture and professional societies, including the Society MacKenzie’s lab, where she was laboratory instruction at her institutions. for Neuroscience. Andrew received his Ph.D. indoctrinated in the major principles of Critical thinking and lifelong learning are two in biochemistry from the University of physiology and the importance of critical characteristics Jennifer hopes to instill in her California at Berkeley. His research interests thinking. The critical thinking component of students. She appreciates the Seeley are focused on the molecular basis of Seeley’s Essentials of Human Anatomy & approach to learning and is excited about migraine. His decision to join the author team Physiology epitomizes Cinnamon’s passion contributing to further development of the for Seeley’s Essentials of Human Anatomy & for the field of human anatomy and textbook. She received her Ph.D. in biology Physiology is the culmination of a passion for physiology; she is committed to maintaining at the University of Houston, under the teaching that began in graduate school. He is this tradition of excellence. Cinnamon and direction of Edwin H. Bryant and Lisa M. excited about the opportunity to hook her husband, Robb (also a biology Meffert. She is an active member of several students’ interest in learning by presenting professor), have two children: a daughter, professional organizations, including the cutting-edge clinical and scientific advances. Savannah, and a son, Ethan. Savannah is Human Anatomy and Physiology Society. Andy is married to Maureen, a physical studying to become a child life specialist. Jennifer is married to Hobbie, a GIS therapist, and has three daughters Erilynn, Ethan is involved in 4-H and shows steers supervisor. They have two sons, Patrick and Becky, and Colleen, and six grandchildren. and lambs. He is pursuing his undergraduate Nicholas. Jennifer and Hobbie enjoy He enjoys all types of outdoor sports, education at Lindenwood University. spending time on their small farm, tending especially bicycling, skiing, running, and open Cinnamon and her family live on a farm with the bees and the chickens, and their spoiled water swimming. her parents, Tom and Bobbie, where they Boston Terrier, Sally. raise sheep and cattle.  Page viii Preface Seeley’s Essentials of Anatomy & Physiology is designed to help students develop a solid, basic understanding of essential concepts in anatomy and physiology without an encyclopedic presentation of detail. Our goal as authors is to offer a textbook that provides enough information to allow students to understand basic concepts, and from that knowledge, make reasonable predictions and analyses. We have taken great care to select critically important information and present it in a way that maximizes understanding. EM PH A SIS ON C R ITIC A L TH IN K IN G Critical thinking skills help students build a knowledge base for solving problems. An emphasis on critical thinking is integrated throughout this textbook. This approach is found in questions at the beginning of each chapter, and embedded within the narrative; in clinical material that is designed to bridge concepts explained in the text with real-life applications and scenarios; in Process Figure questions that apply physiological processes to practical situations, to promote applied understanding; in end-of-chapter questions that go beyond rote memorization; and in a visual program that presents material in understandable, relevant images. Pedagogy builds student comprehension from knowledge to application (Apply It questions, Critical Thinking questions, and Learn to Apply It Answers) Apply It Questions challenge students to use their understanding of new concepts to solve a problem. Answers to the questions are provided at the end of the book, allowing students to evaluate their responses and to understand the logic used to arrive at the correct answer. Critical Thinking These innovative exercises encourage students to apply chapter concepts to solve a problem. Answering these questions helps students build a working knowledge of anatomy and physiology while developing reasoning skills. Answers are provided in Appendix D. Clinical Emphasis—Case Studies Bring Relevance to the Reader When problems in structure and/or function of the human body occur, this is often the best time to comprehend how the two are related. Clinical Impact boxes provide a thorough clinical education that fully supports the surrounding textual material. Systems Pathology boxes provide a modern and systems interaction approach to clinical study of the materials presented. Clinical Impact essays (placed at key points in the text) Chapter-opening clinical scenarios/vignettes Learn to Apply It and chapter Apply It questions with unique Learn to Apply It Answers Systems Pathology Boxes Clinical Impact These in-depth essays explore relevant topics of clinical interest. Subjects covered include pathologies, current research, sports medicine, exercise physiology, pharmacology, and various clinical applications. Page ix Systems Pathology Boxes These spreads explore a specific condition or disorder related to a particular body system. Presented in a simplified case-study format, each Systems Pathology box begins with a patient history followed by background information about the featured topic. Microbes in Your Body helps students to understand the important role microbes play in helping various systems of the body to maintain homeostasis. Effects of Aging describes changes that occur as a person ages. Each reading focuses on the changes that occur in a specific body system. Page x Exceptional Art—Instructive Artwork Promotes Interest and Clarifies Ideas A picture is worth a thousand words—especially when you’re learning anatomy and physiology. Brilliantly rendered and carefully reviewed for accuracy and consistency, the precisely labeled illustrations and photos provide concrete, visual reinforcement of important topics discussed throughout the text. Chapter-opener figures provide a visual overview of major concepts of the chapter, highlighting the components of systems, tissues, or mechanisms that will be explored. Realistic Anatomical Art The anatomical figures in Seeley’s Essentials of Anatomy & Physiology have been carefully drawn to convey realistic, three-dimensional detail. Richly textured bones and artfully shaded muscles, organs, and vessels lend a sense of realism to the figures that helps students envision the appearance of actual structures within the body. Page xi Atlas-Quality Cadaver Images Clearly labeled photos of dissected human cadavers provide detailed views of anatomical structures, capturing the intangible characteristics of actual human anatomy that can be appreciated only when viewed in human specimens. Multi-level Perspective Illustrations depicting complex structures or processes combine macroscopic and microscopic views to help students see the relationships between increasingly detailed drawings. Drawings are often paired with photographs to enhance the visualization of the structures. Histology Micrographs Light micrographs, as well as scanning and transmission electron micrographs, are used in conjunction with illustrations to present a true picture of anatomy and physiology from the cellular level. Page xii Spe c ia lize d Figur e s C la r if y Tough C onc e pt s Studying anatomy and physiology does not have to be an intimidating task mired in memorization. Seeley’s Essentials of Anatomy & Physiology uses two special types of illustrations to help students not only learn the steps involved in specific processes, but also apply the knowledge as they predict outcomes in similar situations. Process Figures organize the key occurrences of physiological processes in an easy-to-follow format. Process Figure questions that follow each figure legend apply physiological processes to practical situations, to promote applied understanding. Homeostasis Figures summarize the mechanisms of homeostasis by diagramming how a given system regulates a parameter within a narrow range of values. Step-by-Step Process Figures Process Figures break down physiological processes into a series of smaller steps, allowing readers to build their understanding by learning each important phase. Numbers are placed carefully in the art, permitting students to zero right in to where the action described in each step takes place. Correlated with APR! Homeostasis Figures with in-art explanations and organ icons These specialized flowcharts illustrating the mechanisms that body systems employ to maintain homeostasis have been refined and improved in the ninth edition. More succinct explanations Small icon illustrations included in boxes depict the organ or structure being discussed.  Page xiii Learn to Apply It and Learn to Apply It Answer—Helping students learn how to think critically A Learn to Apply It question begins each chapter, which links the chapter opener scenario and photo to the topics covered within the chapter. Apply It questions appear throughout each chapter, to reinforce critical thinking. The answers to Learn to Apply It teach students step-by-step how to answer the chapter-opening critical thinking question. These answers to odd-numbered Apply It questions can be found in Appendix E. This is foundational to real learning and is a crucial part of helping students put facts together to reach that “Aha” moment of true comprehension.  Page xiv PED A GOGIC A L FEATU R ES EN SU R E SU C C ESS Learning Outcomes are closely linked with in-chapter Apply It and Learn to Apply It questions as well as the Summary, Critical Thinking, and Review and Comprehension questions. These carefully designed learning aids assist students in reviewing chapter content, evaluating their grasp of key concepts, and utilizing what they’ve learned. Studying Anatomy and Physiology does not have to be intimidating Chapter Summary The summary is now conveniently linked by section and page number while it briefly states the important facts and concepts covered in each chapter. Remembering and Understanding These practice questions cover the main points presented in the chapter. Completing this self-test helps students gauge their mastery of the material. Critical Thinking Questions These innovative exercises encourage students to apply chapter concepts to solve problems. Answering these questions helps build their working knowledge of anatomy and physiology while developing reasoning and critical thinking skills. Page xv  Chapter-by-Chapter Changes Global Changes Added Chapter 0, a student study resource guide with text- specific figure symbols and format guide Added figures spanning two pages that tie together multiple steps of a single process or several ideas into one complete figure Increased vibrancy, clarity, and vividness of colors in the art program Descriptions of process figure events are now within the text with a bullet linking the text to the corresponding portion of the figure to help the student better follow the text Gender-neutral language throughout with use of biological sex pronouns throughout the entire book Bloom’s levels were added to all in-text questions Word pronunciations guides have all been converted to the phonetic pronunciation rather than symbols Throughout, numbering has been added to lists of terms to help reduce cognitive load for the student Chapter 1 Added a situational process figure to illustrate negative and positive feedback Figure 1.8 updated to include the gallbladder Definition of “variable” within homeostasis discussion has been updated to be more accurate Added an analogy to illustrate the importance of body temperature maintenance Modified the definition of positive feedback to be more clear  Reorganized the discussion of positive feedback to flow more logically Updated the definition of etymology for clarity Reworded the definition of ventral and dorsal to be more clear Reorganized section on body cavities to include dorsal body cavity, a term commonly used within the allied health fields Reorganized the body membranes section to flow more logically Integrated clinical information into the body cavities section Chapter 2 Added a figure demonstrating the relationship between electronegativity and bond formation (fig 2.2) Added figures demonstrating electron distribution between atoms, depending on bond type (figs 2.4 and 2.5) Added figure depicting electron position within a molecule with polar bonds (2.5) Added figure demonstrating the relationship between pH and H+ and the connection to household items (fig 2.10) Figure 2.11 on buffers has been revised for clarity Added definition of an “electron cloud” Per a reviewer’s suggestion, added definition of isotope Updated the definition of ionic bonding for clarity Simplified the discussion of chemical bonds by integrating a stepwise association with the corresponding process figure; it is now more logical Rearranged the order of the discussion of energy for simplicity and clarity Added the definition of “gene” to nucleic acid discussion Chapter 3 New chapter-opener figure  New figure 3.1 highlighting the components of a cell Added headings to distinguish between passive membrane transport processes and active membrane transport processes Description of transcytosis added Chapter 4 Revised tables that list tissue types to make it easy to compare one tissue to another tissue Added two 2-page figures illustrating the distribution of epithelial and connective tissues throughout the body Updated the description of epithelial tissue for clarity Changed the descriptions of the epithelial tissue types to be more succinct Reorganized the discussion of epithelial tissue types to be more logical Reorganized the discussion of secretory glands for logic and clarity Added a table organizing gland type by structure and mode of secretion Per reviewer suggestion, added a new Apply It question to the muscle tissue section Reorganized the discussion of inflammation to correspond with the accompanying process figure Reorganized the discussion of tissue repair to correspond with the accompanying process figure Chapter 5 New chapter-opener figure List of five epidermal strata added Description of thick skin versus thin skin added Page xvi  Added term friction ridge and explained its relationship to fingerprints Added explanation of why different types of injections are used Description of fourth-degree burns added Chapter 6 Added a figure illustrating the anatomy of spongy bone Updated the figure depicting the process of intramembranous ossification for clarity Updated the figure depicting the process of endochondral ossification to include a timeline for when each event occurs Updated the figure of the overview of skeletal anatomy to visually differentiate between axial skeleton and appendicular skeleton Added a figure of the superior view of the skull for better visualization of skull sutures Updated multiple figures throughout the chapter to have more distinct detail and more vivid coloration Revised the introduction to bone matrix section to better illustrate the relationship between form and function, with a reference to chapter 4 Reorganized the order of chapter sections for more logical flow Added a new figure comparing the three bone-cell types Rewrote the section on bone histology to clarify the function of each bone cell Reorganized the section on bone development to correlate with the process figures Reorganized the section on bone repair to correlate with the process figure Rewrote the section on Ca2+ homeostasis to flow more logically and to be more clear  Replaced figure 6.10 with a homeostasis figure to simplify the visual representation of Ca2+ homeostasis The skull bone anatomy has been rearranged to be organized by bone rather than by view of skull to streamline this information and reduce redundancy The section on appendicular bone anatomy has been reorganized by girdle, then by bone The section on joints has been reorganized to be more logical Chapter 7 The art has been updated to be more vivid and realistic The physiology art is reorganized with new figures that help the students keep track of what portion of the process they learning and how it relates to the other steps in the sequence as well as the location within the cell Updated the figure illustrating energy sources for muscle contraction to be more streamlined and logical Reorganized section 7.3 on skeletal muscle anatomy to be more logical and to be more clear Added an organizing principle to skeletal muscle fiber anatomy and its role in muscle contraction Added a figure illustrating the resting membrane potential Reorganized the section on action potentials to correlate with the corresponding process figure Reorganized the section on the neuromuscular junction to correlate with the corresponding process figure Rewrote the portion of this section that describes the link between the action potential and muscle shortening Incorporated an active learning tip for the cross-bridge cycle Rewrote the portion of this section describing the cross- bridge cycle to correlate with the corresponding process figure Reorganized the section on whole-muscle physiology to flow more logically  The term recovery oxygen consumption is replaced with excess post-exercise consumption Updated the section on energy sources for contraction to reflect more current terminology Added a study tip for approaching the learning of skeletal muscle anatomy Reorganized the anatomy section to include more separate sections of muscles for clarity Updated the description of the pelvis diaphragm for accuracy Chapter 8 New chapter-opener figure New figure representing the organization of the nervous system Added description of satellite cells in the discussion of PNS glial cells Revised the section “Resting Membrane Potential” for clarity New figure highlighting the phase of nerve cell communication: stimulation of action potential, action potential propagation, and synaptic communication Added active learning prompts (action potential propagation) Moved the description of reflexes to discussion of spinal cord to eliminate redundancy Changed to “dorsal” and “ventral” in reference to horns in spinal segment description Page xvii Statement added about the function of the insula (taste perception) Replaced the term “primary somatic sensory cortex” with the term “primary somatosensory cortex” Chapter 9  New chapter-opener figure Additional information concerning proprioception and the righting reflex added Section on “Pain” revised for clarity Description of photoreceptor function moved to the section “Function of the Eye” so that physiological processes are grouped together New figure highlighting the process of vision added Chapter 10 Added a figure comparing transport of water-soluble hormones to lipid-soluble hormones Updated figure 10.3 for clarity Updated figure 10.10 for clarity Updated the discussion of binding proteins to be more clear Rewrote the section on water-soluble hormone transport to be more logical Reorganized the discussion of control of hormone secretion to correlate with the corresponding process figure Deleted figure 10.9 and incorporated some of that information into figure 10.10 to be clearer and less visually detailed Updated information on prolactin-inhibiting hormone for accuracy Reorganized the discussion on the adrenal cortex to be more logical Deleted figure 10.20 to be more in line with the level of detail throughout the chapter; this topic is discussed further in chapter 18 Chapter 11 New chapter-opener figure  Updated description of red blood cell structure to accurately relate to function Updated figure 11.2 to reflect level of detail in the text New figure of life history of red blood cell added Revised figure detailing the breakdown of hemoglobin for clarity New figure illustrating blood typing added Chapter 12 New chapter-opener figure New two-page figure highlighting the Cardiac Cycle Section 12.5, “Stimulation of the Heart,” has been updated with a introduction to prepare students for the detailed description of action potentials and cardiac muscle activity Panel labels have been added to figure 12.19, Events of the Cardiac Cycle, to correlate with references in the text, which will help the reader interpret the multiple graphs Clear descriptions of extrinsic regulation and intrinsic regulation added to the introduction of section 12.8, “Regulation of Cardiac Function” Chapter 13 New chapter-opener figure Figure 13.24 revised for clarity New figure 13.21 summarizes the regulation of blood flow Chapter 14 New chapter-opener figure New figure 14.8 summarizes the components of immunity Revised description of specificity in section 14.3 for clarity Revised description of self antigen for accuracy  Revised the section “Antigen Recognition” for accuracy and clarity Figure 14.11 revised to include memory helper T cells Chapter 15 This chapter has been completely reorganized and rewritten for more coherent flow of information The discussion of ventilation and gas laws has been combined Organized the physiology discussion into respiration versus gas transport with a separate section on metabolic factors affecting gas transport Figure 15.13 was updated to depict O2 molecules bound to the hemoglobin molecule Added an overview figure of CO2 transport mechanisms Chapter 16 Rearranged figure 16.9 to better illustrate each of the three phases of swallowing Added a part (e) to figure 16.11 to illustrate the specific location of nutrient absorption Updated figure 16.23 to include images of the nutrient molecules Updated figure 16.24 with a better representation of digestive actions in each region of the digestive tract Updated figures 16.25 and 16.26 to be more realistic Updated the anatomy description of the stomach to be more clear Page xviii Reorganized the text in section 16.4 to correlate with the corresponding process figure Rewrote the anatomy description of the liver to better illustrate the relationships among its components  Rewrote the description of bile to be more clear Reorganized the section on functions of the liver to correlate with the corresponding figure Rewrote the section on the anatomy of the pancreas to be more clear Rewrote the section on the defecation reflex to be more coherent Chapter 17 New chapter-opener figure New figure 17.4 illustrates the pathways of macromolecule breakdown for ATP production Updated the numbers of ATP produced from glucose metabolism Chapter 18 Added a figure depicting urine flow through the urinary system (figure 18.4) Added a flowchart depicting blood flow through the kidney (figure 18.7) Edited figure 18.8 to show the urine formation process with a more realistic relationship to the nephron Figure 18.9 was revised to be clearer and to link to other corpuscle images Figure 18.10 was revised as a two-page spread highlighting the reabsorption of solutes and water Figure 18.13 was recast as a two-page spread to illustrate water conservation and filtrate flow Figure 18.15 was edited to include details of the collecting duct Per reviewer request, a photomicrograph of transitional epithelium was added to figure 18.18  Per reviewer request, figure 18.20 as added to review the principles of osmosis Rewrote the section on urine flow to correspond to the new portion of figure 18.4 Throughout the chapter, the text was reorganized to correlate with the corresponding process figures Per reviewer request, added a discussion of countercurrent mechanism to help provide context for the ability of the kidney to conserve water Rewrote the section on renin-angiotensin-aldosterone to be more logical Rewrote the section on intracellular fluid compartments and extracellular fluid compartments Rewrote the section on Na+ regulation for clarity Rewrote the section on Ca2+ homeostasis to be clearer Simplified the section on buffers Chapter 19 Figure 19.5 revised as a two-page figure outlining the process of spermatogenesis Figure 19.11 revised as a two-page figure outlining the maturation of the oocyte and follicle Rewrote the section on meiosis to be clearer Meiosis discussion now correlates with the corresponding process figure Added a new Clinical Impact box, “Gender and Sex,” introducing the concept of the difference between biological sex and gender identity Rewrote the section on the anatomy of the scrotum to clarify the relationship between temperature and sperm development Rewrote the text on spermatogenesis to correlate with the corresponding process figure  Used biological sex terms rather than gender terms throughout the chapter Rewrote the section on infertility in males for clarity Integrated the discussion on follicle development and oocyte development to reduce redundancy Revised the statement on the length of the menstrual cycle to be more general Updated the section on birth control to be more current Chapter 20 New chapter-opener figure Introduction to section 20.1, “Prenatal Development,” revised to include list of prenatal and postnatal life stages Discussions of neural tube and neural crest formation revised for clarity Description of formation of the heart revised to better reflect the detail in figure 20.13  Page xix List of Clinical Impact Essays Chapter 1 Cadavers and the Law 13 Chapter 2 Applications of Atomic Particles 43 Chapter 3 Cystic Fibrosis 68 Cancer 81 Chapter 4 Effect of Smoking on Air Passageway Epithelium 91 Chapter 5 Skin Cancer 116 Acne: Using Bacteria to Fight Bacteria 118 Chapter 6 Classification of Bone Fractures 138 Chapter 8 Spinal Cord Injury 240 Biofeedback and Meditation 266 Chapter 9 Corneal Transplants 279 Color Blindness 284 Chapter 11 Stem Cells and Cancer Therapy 334 Clinical Importance of Activating Platelets 340 Anemia 349 Chapter 12 Disorders of the Pericardium 357 Heart Attack 364 Consequences of Heart Failure 375 Chapter 13 Varicose Veins 388 Blood Vessels Used for Coronary Bypass Surgery 398 Hypertension 400 Circulatory Shock 410 Chapter 14 Treating Viral Infections and Cancer with Interferons 428 Use of Monoclonal Antibodies 436 Chapter 15 Establishing Airflow 453 Effects of High Altitude and Emphysema 471 Chapter 16 Dietary Fiber 489 Peptic Ulcers 496 Chapter 17 Free Radicals and Antioxidants 525 Starvation and Obesity 537 Too Hot or Too Cold 540 Chapter 19 Gender and Sex 579 Descent of the Testes 582 Pattern Baldness 591 Cancer of the Breast 597 Amenorrhea 600 Chapter 20 In Vitro Fertilization and Embryo Transfer 621  Page xx Instructors: Student Success Starts with You Tools to enhance your unique voice Want to build your own course? No problem. Prefer to use our turnkey, prebuilt course? Easy. Want to make changes throughout the semester? Sure. And you’ll save time with Connect’s auto-grading too. Study made personal Incorporate adaptive study resources like SmartBook® 2.0 into your course and help your students be better prepared in less time. Learn more about the powerful personalized learning experience available in SmartBook 2.0 at www.mheducation.com/highered/connect/smartbook  Laptop: McGraw-Hill Education Affordable solutions, added value Make technology work for you with LMS integration for single sign-on access, mobile access to the digital textbook, and reports to quickly show you how each of your students is doing. And with our Inclusive Access program you can provide all these tools at a discount to your students. Ask your McGraw Hill representative for more information. Padlock: Jobalou/Getty Images Solutions for your challenges A product isn’t a solution. Real solutions are affordable, reliable, and come with training and ongoing support when you need it and how you want it. Visit www.supportateverystep.com for videos and resources both you and your students can use throughout the semester. Checkmark: Jobalou/Getty Images Page xxi Students: Get Learning that Fits You Effective tools for efficient studying Connect is designed to make you more productive with simple, flexible, intuitive tools that maximize your study time and meet your individual learning needs. Get learning that works for you with Connect. Study anytime, anywhere Download the free ReadAnywhere app and access your online eBook or SmartBook 2.0 assignments when it’s convenient, even if you’re offline. And since the app automatically syncs with your eBook and SmartBook 2.0 assignments in Connect, all of your work is available every time you open it. Find out more at www.mheducation.com/readanywhere “I really liked this app—it made it easy to study when you don't have your textbook in front of you.” - Jordan Cunningham, Eastern Washington University Everything you need in one place Your Connect course has everything you need—whether reading on your digital eBook or completing assignments for class, Connect makes it easy to get your work done.  Calendar: owattaphotos/Getty Images Learning for everyone McGraw Hill works directly with Accessibility Services Departments and faculty to meet the learning needs of all students. Please contact your Accessibility Services Office and ask them to email [email protected], or visit www.mheducation.com/about/accessibility for more information. Top: Jenner Images/Getty Images, Left: Hero Images/Getty Images, Right: Hero Images/Getty Images Page xxii  Page xxiii Acknowledgments In today’s world, no textbook is brought to fruition through the work of the authors alone. Without the support of friends, family, and colleagues, it would not have been possible for us to complete our work on this text. The final product is truly a team effort. We want to express sincere gratitude to the staff of McGraw Hill for their help and encouragement. We sincerely appreciate Senior Portfolio Manager Matt Garcia and Product Developer Melisa Seegmiller for their hours of work, suggestions, patience, and undying encouragement. We also thank Content Project Manager Ann Courtney, Content Licensing Specialist Lori Hancock, Buyer Laura Fuller, and Designer David Hash for their hours spent turning a manuscript into a book; Assessment Project Manager Brent dela Cruz for his assistance in building the various products that support our text; and Marketing Manager Valerie Kramer for her enthusiasm in promoting this book. The McGraw Hill LLC employees with whom we have worked are extremely professional, but more than that, they are completely dedicated to their role as part of the content team. Finally, we sincerely thank the reviewers and the teachers who have provided us with excellent constructive criticism. The remuneration they received represents only a token payment for their efforts. To conscientiously review a textbook requires a true commitment and dedication to excellence in teaching. Their helpful criticisms and suggestions for improvement were significant contributions that we greatly appreciate. We acknowledge them by name in the next section. Cinnamon VanPutte Jennifer Regan Andy Russo REVIEWERS Malene Arnaud-Davis Delgado Community College Justin Bradshaw Johnston Community College Susan Caley Opsal Illinois Valley Community College Maria J Crowe Marquette University Craig Denesha Spartanburg Community College Roberta C. Harnish Indiana University Northwest Kazi Nazrul Islam Delgado Community College Pamela B. Jackson Piedmont Technical College Sudeep Majumdar Temple College, Tx Karen K. McLellan Purdue University Fort Wayne Rebekah Murphy Wichita State University Amy E. Picchi Eastern Florida State University Angela R. Porta Kean University Padmaja Vedartham Lone Star College Scott Wersinger University at Buffalo, SUNY Rachel Willard Arapahoe Community College Heather Wilson-Ashworth Utah Valley University Remote Proctoring & Browser-Locking Capabilities New remote proctoring and browser-locking capabilities, hosted by Proctorio within Connect, provide control of the assessment environment by enabling security options and verifying the identity of the student. Seamlessly integrated within Connect, these services allow instructors to control students’ assessment experience by restricting browser activity, recording students’ activity, and verifying students are doing their own work. Instant and detailed reporting gives instructors an at-a-glance view of potential academic integrity concerns, thereby avoiding personal bias and supporting evidence-based claims.  Page xxiv ELEVENTH EDITION Seeley’s Essentials of Anatomy & Physiology  Page 1 CHAPTER 0 How to Be Successful in A&P dotshock/Shutterstock Page 2 Hello, Students! Author Cinnamon VanPutte would like to share something with you: she failed her college organic chemistry course. Later, she retook it and earned an “A.” Why does this matter to you? We hope this helps you understand that your authors have been there. Yes, we’ve earned an “A” in hard classes—but we also know what it is to struggle in a class. We’ve had to retool our study habits; we’ve had to learn how to effectively use a textbook. These experiences have helped inform our approach to this textbook, and we hope this helps you. We know that many of you will sail right through A&P and would have done so even without reading this success guide, while others may be retaking A&P for the second or third time. By taking the time to read this guide, you have already taken a positive first step to being able to succeed in A&P. You have entered a partnership with your instructor and us, the authors. If you utilize the tips, techniques, and information that we, as well as your instructors, are providing to you, we know you will learn a lot of information and you will be positioned to succeed in this course. 0.1 THE WORLD OF A&P If you search online for “hardest classes in college,” A&P will show up on many lists. But don’t worry! We are here to help! We have each taught A&P for more than 20 years and have seen countless students, who were very nervous on the first day, successfully move through the course—all the while gaining self- assurance, confidence, and a deep understanding of the fundamental concepts needed to perform well in the course. The study of A&P entails a lot of information. Depending on the particular course, the first semester of A&P may start with a discussion of matter and chemical bonds, and end with the complexities of the nervous system (such as action potentials). Truthfully, this means progressing from introductory material to more advanced material within a single semester. In addition, you will be learning the vocabulary of A&P, which means you are essentially learning a foreign language—you might even feel like you’re learning more new vocabulary than if you were actually learning a foreign language! In an effort to make this task easier, our textbook provides phonetic pronunciations of these vocabulary terms, similar to those found on Facebook for people’s names. For example, the gluteus maximus pronunciation would be: GLOO-tee-us MAX-ih-mus. We think this type of guide will help you learn the terminology very readily and be more confident speaking the language—if you can say it out loud, then you can probably spell it and are better poised to remember it. It’s also important to realize that the information in A&P cannot be effectively understood through memorization alone. Much of the physiology material requires that you use critical thinking skills. Many of you may be planning careers in science or health professions, such as nursing or pharmacy —professions in which the ability to problem solve is essential. In this book we will help you develop critical thinking skills and thus a deep understanding of complex concepts. 0.2 DEVELOPING CRITICAL THINKING SKILLS So, what is required to develop critical thinking skills? What even are critical thinking skills? To understand these questions, we need to explore the difference between simple memorization—what you may have always called “studying”—and conceptual learning. Many of you have enjoyed much success in high school and in some of your early introductory-level college classes through “studying.” However, to be successful in most A&P classes, you will also need to develop skills for conceptual learning. The basis for this difference is best described using Bloom’s taxonomy, originally published by B. Bloom and colleagues in 1956. Over time, Bloom’s taxonomy has been modified and can be best thought of as a model for the gradual increase in the amount of abstract thought required to achieve a particular level of learning. The simplest, most concrete level of learning is remembering, or simply memorizing. As you climb the levels of Bloom’s, your ability to put ideas into your own words (understanding) and then to solve problems you’ve never seen before (applying) increases. Thus, as you gain these skills, you are now learning the material and can answer how and why a particular process happens, and you can predict outcomes to unfamiliar scenarios. This textbook will guide you in developing those skills. To do this, you will begin to use metacognition in your learning. Metacognition was first defined by Flavell in 1976 as “thinking about your own thinking”—in other words, deciding whether you truly understand and can apply fundamental physiological and anatomical principles. We are going to provide you with five metacognitive learning strategies to ensure your success in A&P. 0.3 FIVE METACOGNITIVE LEARNING STRATEGIES What will you need to do to achieve the goal of being successful in A&P? There are five specific tasks you can employ to be successful in A&P. These tasks are adapted from the book Teach Students How to Learn by S. Y. McGuire. They are the following: 1. Attend every class session and take notes with a pen and paper. 2. Read, read, read! 3. Work with other students. 4. Do homework as if it were the test. 5. Engage in concentrated study sessions. We will address each of these tasks in the remainder of this success guide with specific information on how to use this textbook. Page 3 0.4 USING THE FIVE METACOGNITIVE LEARNING STRATEGIES WITH THIS TEXTBOOK 1. Attendance and Note-Taking. It is essential that you attend each class session. As you can see, this book has 20 chapters, each of which covers a topic for which you could take an entire semester class, or more! Your instructor will decide what material they will cover. Some instructors may expect you to glean specific information directly from the book. Therefore, to make sure you hear, firsthand, all the information and messages your instructor presents in class, it is critical you be in class. Then, while in class, take notes by hand! Students who handwrite their notes outperform students who take notes with their laptops. The difference is that taking notes by hand requires you to use your own words, which helps you remember the information better. After the class session, it is also helpful to take notes by hand directly from the assigned chapters. 2. Read, Read, Read! Possibly one of the biggest misconceptions regarding reading a textbook is that it is no different from reading a novel—which couldn’t be farther from the truth. Reading a science textbook involves a slow and systematic process. There are three types of reading strategies you’ll need to employ to get the most information from each chapter: (1) preview, (2) prepare for active reading, (3) actively read. a. Preview Previewing a chapter is like watching a movie trailer or reading the description of a book to see what it’s about and whether it interests you. Skim the section headings. Each system chapter of this textbook is laid out in the following way: Anatomy of the System Organs Histology Functions of the System Major Functions Integration of Functions for Homeostasis Some sections are further subdivided into specialized topics to walk you through a process step-by-step. While you’re previewing the chapter, pay attention to bolded terms, phonetic pronunciations, and word origins. Root words tell a lot of information about a process or structure; for example, hyper- indicates higher or above, and hypo- indicates lower or below, and they are used both anatomically and physiologically. b. Prepare for Active Reading As you’re previewing, or as a next step, write out questions you’d like answered as you read. The bold terms can be used as a guide to the questions. c. Actively Read  After you’ve previewed the chapter and have done the preparations for active reading, the next step is to actively read. This can be done one paragraph, or one concept in SmartBook 2.0, at a time. Write notes in your own words as you read. Add a paragraph, or concept, at a time, all the while adding ideas from the previous paragraph. In this way, you’re “taking one bite at a time” of the chapter’s information. This helps your brain integrate information and keeps it from suffering information overload. As you actively read, there are several features that are consistent throughout this text that can serve as guideposts for you. We present these features in the section “Textbook Features and Figure Colors and Symbols.” 3. Work with Other Students Enrolled in the Same Class. Author C. VanPutte would like to share something else with you: she did not fully comprehend the concept of osmosis until she taught her first college-level class. Once she had to explain the concept out loud and in her own words, a light clicked on! So, form study groups! Assign each other topics on which to lecture to the group. Write practice exams for each other. Sometimes your peers can help you as much as, or perhaps more than, the instructor. 4. Do Homework as if It Were the Test. For most lecture exams you will not be allowed to use your notes, the textbook, or the internet. So you need to practice for that situation. Don’t simply copy answers onto your homework assignments. Instead, study first, then do the homework without assistance. Then, if you get stuck, use your resources. For example, you could do a “recharge” in SmartBook 2.0, or visit your instructor during their office hours. 5. Utilize Multiple, Intense, Short Study Sessions. Our brains work more efficiently when we stay focused for a relatively brief period of time: approximately 30–50 minutes. Staring blankly at your notes for 3 hours is not helpful. Therefore, decide what you’re going to focus on, then study with intent for 30–50 minutes. Studying with intent involves actively engaging with the material. This can include making a concept map, expanding on your notes and rephrasing them, writing out a summary and simply thinking about the material. Take a short 10- to 15-minute break, then briefly review what you just studied. Do this 3–5 times a day for each class in which you’re enrolled. 0.5 TEXTBOOK FEATURES AND FIGURE COLORS AND SYMBOLS Throughout this textbook you will see certain repeating features and symbols. These symbols are always a particular color; however, for our students with vision disabilities, these colored symbols are also uniquely labeled. 1. In-Text Numbering As you’re reading, look for areas where we’ve tried to make complex topics clearer by numbering steps or components. This ensures that you don’t miss a step or a part. Page 4 2. Process Figures For complex processes, we have process figures that break down the step-by-step sequence of events. The in-text explanations directly correlate to portions of the figure by the use of purple circle numbers. 3. Side-by-Side Anatomy Figures In certain anatomy figures, we have placed a photograph next to an artistic rendering. This allows for accurate interpretation of artist-generated figures.  McGraw Hill Education/Photo and Dissection by Christine Eckel Page 5 4. Homeostasis Figures These figures walk you through certain critical physiological mechanisms involved in the maintenance of homeostasis. Icons depict the particular organs discussed, in order to help strengthen associations between anatomy and physiology.  Page 6 5. Clinical Content a. Clinical Impact: explore interesting clinical aspects of the body system being discussed b. Microbes in Your Body: highlight the role of microbes in maintaining homeostasis c. Aging: describe changes to the body systems as we age  d. Systems Pathologies: discuss a disorder or disruption in a particular body system Page 7 6. Critical Thinking Practice The textbook presents you with multiple opportunities to practice applying the information you’ve learned to particular situations. Critical Thinking questions require a higher-order level of thinking than simple fact-based questions. The Bloom’s Taxonomy icon indicates the level at which a given question is ranked. a. Learn to Apply It This feature appears at the beginning of each chapter and integrates information from earlier chapters or asks you to think about a scenario as you read the chapter. Answers to odd-numbered questions are provided online or in the  appendices. The answers are written in a solution-style format. We walk you through the logic of each answer. b. Apply It Apply It questions are distributed throughout each chapter and pertain to information presented prior to each question. The same solution-style format answers to the odd-numbered questions are provided. c. Critical Thinking Critical Thinking questions typically require a higher-order level of thinking than the Apply It questions. Solution-style-format answers are also provided for these. 7. Figure Colors and Symbols Following are symbols used consistently to indicate the same structure or event in all chapters. If in some chapter a symbol is given a different usage, that usage for the symbol is always labeled or defined. Symbol Meaning Information and level flow Describe steps in a process To decrease or inhibit To increase or stimulate Channel proteins and ions Pink: Na+ Purple: K+ Green: Ca2+ Blue: Phospholipid bilayer of cell membrane Yellow: Cytoplasm/inside of cell Sodium/potassium pump  Acetylcholine Sympathetic nervous system Parasympathetic nervous system Action potential Generic ligand Generic ligand receptor G Protein Veins with deoxygenated blood Arteries with oxygenated blood Page 8 CONCLUSIONS In our teaching we have seen, time and time again, that the students who put in the effort and utilize the activities described in this guide consistently outperform the students who do not. Thus, it will be your perseverance, sometimes called grit—and not how “smart” you are—that will enable your success. Encourage yourself, believe in yourself, and never quit. Design Elements: (Microbes in Your Body): Janice Haney Carr/CDC; (Clinical Impact): Comstock/Alamy Stock Photo  Page 9 CHAPTER 1 The Human Organism  The human body is a complex system. The structures in the body work in concert to maintain homeostasis, a balance in the body’s internal environment. Page 10 LEARN TO APPLY IT Renzo, a dancer, can move his body such that it is perfectly balanced, yet a slight movement in any direction would cause him to adjust his position. The human body adjusts its balance among all its parts through a process called homeostasis. Let’s imagine that Renzo is suffering from a blood sugar disorder. Earlier, he’d eaten an energy bar. As an energy bar is digested, blood sugar rises. Normally, tiny collections of cells embedded in the pancreas respond to the rise in blood sugar by secreting the chemical insulin. Insulin increases the movement of sugar from the blood into the cells. However, Renzo did not feel satisfied from his energy bar. He felt dizzy and was still hungry, all symptoms he worried could be due to a family history of diabetes. Fortunately, the on-site trainer tested his blood sugar and noted that it was much higher than normal. After a visit to his regular physician, Renzo was outfitted with an insulin pump and his blood sugar levels are more consistent. What is a good explanation for Renzo’s blood sugar levels before and after his visit to the doctor? Answers to this question and the chapter’s odd-numbered Apply It questions can be found in Appendix E. Module 1 Body Orientation 1.1 ANATOMY AND PHYSIOLOGY Learning Outcomes After reading this section, you should be able to A. Define anatomy and describe the levels at which anatomy can be studied. B. Explain the importance of the relationship between structure and function. C. Define physiology and describe the levels at which physiology can be studied. What lies ahead is a fantastic adventure—learning about the structure and function of the human body and the intricate checks and balances that regulate it. Perhaps you have had the experience of oversleeping, rushing to your 8 a.m. class, and missing breakfast. Afterward, on the way to your Anatomy & Physiology class, you bought an energy bar from the vending machine. Eating the energy bar helped you feel better. The explanation for this experience is the process of homeostasis, the maintenance of a relatively constant internal environment despite fluctuations in the external environment. For you, homeostasis was maintained, but for Renzo, the dancer in this chapter’s Learn to Apply It feature, there was a disruption in homeostasis. Throughout this book, the major underlying theme is homeostasis. As you think about Renzo’s case, you will come to realize just how capable the human body is of an incredible coordination of thousands upon thousands of processes. Learning about human anatomy and physiology is important for understanding disease. The study of human anatomy and physiology is important for students who plan a career in the health sciences because health professionals need a sound knowledge of structure and function in order to perform their duties. In addition, understanding anatomy and physiology prepares all of us to evaluate recommended treatments, critically review advertisements and reports in the popular literature, and rationally discuss the human body with health professionals and nonprofessionals. Anatomy (ah-NAT-oh-mee) is the scientific discipline that investigates the structure of the body—for example, the parts and chambers of the heart. The word anatomy means to dissect, or cut apart and separate, the parts of the body for study. In addition, anatomy examines the relationship between the structure of a body part and its function. For example, the structure of a hammer informs us of its primary use of driving nails into wood. Similarly, the fact that bone tissue is a hard, mineralized substance enables the bones to provide strength and support. Understanding the relationship between structure and function makes it easier to understand and appreciate anatomy. There are two basic approaches to the study of anatomy: (1) systemic anatomy and (2) regional anatomy. Systemic anatomy is the study of the body by systems, such as the cardiovascular, nervous, skeletal, and muscular systems. It is the approach taken in this textbook. Regional anatomy is the study of the organization of the body by areas. Within each region, such as the head, abdomen, or arm, all systems are studied simultaneously. This is the approach taken in many medical and dental schools. Anatomists have two general ways to examine the internal structures of a living person: (1) surface anatomy and (2) anatomical imaging. Surface anatomy is the study of external features, such as bony projections, which serve as landmarks for locating deeper structures. For example, the sternum (breastbone) is used by health professionals as a landmark for listening to heart sounds. Anatomical imaging involves the use of x-rays, ultrasound, magnetic resonance imaging (MRI), and other technologies to create pictures of internal structures, such as when determining if a bone is broken or a ligament is torn. Both surface anatomy and anatomical imaging provide important information for diagnosing disease. Physiology (fiz-ee-OL-oh-jee; the study of nature) is the scientific discipline that deals with the processes or functions of living things—it is important in physiology to recognize structures as dynamic. There are two major goals when studying physiology: (1) examining the body’s responses to stimuli and (2) examining the body’s maintenance of stable internal conditions. Human physiology is the study of humans. Like anatomy, physiology can be studied at multiple levels. For example, cellular physiology focuses on processes inside cells such as the manufacturing of substances, including proteins, whereas systemic physiology focuses on the functions of organ systems. Page 11 1.2 STRUCTURAL AND FUNCTIONAL ORGANIZATION OF THE HUMAN BODY Learning Outcomes After reading this section, you should be able to A. Describe the six levels of organization of the body, and describe the major characteristics of each level. B. List the eleven organ systems, identify their components, and describe the major functions of each system. The body can be studied at six structural levels: chemical, cell, tissue, organ, organ system, and organism (figure 1.1). PROCESS Figure  PROCESS Figure 1.1 Levels of Organization for the Human Body The simplest level of organization in the human body is the atom. Atoms combine to form molecules. Molecules aggregate into cells. Cells form tissues, which combine with other tissues to form organs. Organs work in groups called organ systems. All organ systems work together to form an organism. 1.1(6) BJI/Blue Jean Images/Getty Images Why is the skin considered an organ? What characterizes the integumentary system as an organ system? 1 Chemical Level The structural and functional characteristics of all organisms are determined by their chemical makeup. The chemical level of organization involves how atoms, such as hydrogen and carbon, interact and combine into molecules. This is important because a molecule’s structure determines its function. For example, collagen molecules are strong, ropelike fibers that give skin structural strength and flexibility. With aging, the structure of collagen changes, and the skin becomes fragile and more easily torn during everyday activities. We present a brief overview of chemistry in chapter 2. 2 Cell Level Cells are the basic structural and functional units of organisms, such as plants and animals. Most cells contain smaller structures inside them, called organelles (OR-gah-nellz; little organs). Organelles carry out particular functions, such as digestion and movement, for the cell. For example, the nucleus contains the cell’s hereditary information, and mitochondria manufacture adenosine triphosphate (ATP), a molecule cells use for a source of energy. Although cell types differ in their structure and function, they have many characteristics in common. Knowledge of these characteristics as well as their variations is essential to understanding anatomy and physiology. We discuss the cell in chapter 3. Page 12 MICROBES IN YOUR BODY Getting to Know Your Bacteria Did you know that you have more microbial cells than human cells in your body? Astoundingly, for every cell in your body, there is one microbial cell. That’s as many as 40 trillion microbial cells, which collectively can account for 2 to 6 pounds of your body weight! A microbe is any life form that can only be seen with a microscope (for example, bacteria, fungi, and protozoa). All living organisms fit into one of three domains of living organisms: (1) Bacteria, (2) Archaea, and (3) Eukarya. The cells of organisms in each domain are unique. Bacterial cells’ genetic material is not separated from the rest of the cell by a barrier. In addition, bacterial cells have far fewer separate structures made of membrane for carrying out the cell’s metabolic processes than eukaryotic cells. Archaea cells are constructed similarly to bacteria; however, they share certain structures, called ribosomes, with eukaryotic cells. We will discuss cell structure in detail in chapter 3. Commonly, the term prokaryotic is used to describe bacterial and archaea cells. Eukarya cells, which include human cells, have the most structural complexity with many smaller structures, called organelles, surrounded by membranes. These smaller structures conduct the metabolic processes of the cell. In addition to structural differences, there are many other differences far too numerous to adequately describe here. However, size differences between bacteria and archaea and cells of eukaryotes is quite evident with most eukaryotic cells being significantly larger than most prokaryotic cells. The total population of microbial cells on the human body is referred to as the microbiota, while the collection of all the microbial cell genes is known as the microbiome. The microbiota includes so-called good bacteria,  which do not cause disease and may even help us. It also includes pathogenic, or “bad,” bacteria. With that many microbes in and on our bodies, you might wonder how they affect our health. To answer that question, the National Institutes of Health (NIH) initiated the Human Microbiome Project. Five significant regions of the human body were examined: the airway, skin, mouth, gastrointestinal tract, and vagina. This project identified over 5000 species and sequenced over 20 million unique microbial genes. What did scientists learn from the Human Microbiome Project? Human health is dependent upon the health of our microbiota, especially the “good” bacteria. More specifically, the human microbiome is intimately involved in the development and maintenance of the immune system. And more evidence is mounting for a correlation between a host’s microbiota, digestion, and metabolism. Researchers have suggested that microbial genes are more responsible for our survival than human genes are. There are even a few consistent pathogens that are present without causing disease, suggesting that their presence may be good for us. However, there does not seem to be a universal healthy human microbiome. Rather, the human microbiome varies across life span, ethnicity, nationality, culture, and geographic location. Instead of being a detriment, this variation may actually be very useful for predicting disease. There seems to be a correlation between autoimmune and inflammatory diseases (Crohn’s disease, asthma, multiple sclerosis), which have become more prevalent, and a “characteristic microbiome community.” Early research seems to indicate that any significant change in the profile of the microbiome of the human gut may increase a person’s susceptibility to autoimmune diseases. It has been proposed that these changes may be associated with exposure to antibiotics, particularly in infancy. Fortunately, newer studies of microbial transplantations have shown that the protective and other functions of bacteria can be transferred from one person to the next. However, this work is all very new, and much research remains to be done. Throughout this text, we will highlight specific instances in which our microbes influence our body systems. In light of the importance of our bodies’ bacteria and other microbes, the prevalence of antibacterial soap and hand gel usage in everyday life may be something to think about. 3 Tissue Level A tissue (TISH-you) is a group of similar cells and the materials surrounding them. The characteristics of the cells and surrounding materials determine the functions of the tissue. The many tissues that make up the body are classified into four primary types: (1) epithelial, (2) connective, (3) muscle, and (4) nervous. We discuss tissues in chapter 4. 4 Organ Level An organ (OR-gan; a tool) is composed of two or more tissue types that together perform one or more common functions. For example, the heart, stomach, liver, and urinary bladder are all organs (figure 1.2). 5 Organ System Level An organ system is a group of organs that together perform a common function or set of functions. For example, the urinary system consists of the kidneys, ureters, urinary bladder, and urethra. The kidneys produce urine, which is transported by the ureters to the urinary bladder, where it is stored until being eliminated from the body through the urethra. In this text, we consider eleven major organ systems: (1) integumentary, (2) skeletal, (3) muscular, (4) nervous, (5) endocrine, (6) cardiovascular, (7) lymphatic, (8) respiratory, (9) digestive, (10) urinary, and (11) reproductive. Figure 1.3 presents a brief summary of these organ systems and their functions. Page 13 Figure 1.2 Major Organs of the Body The body’s major organs include the brain, lungs, heart, liver, pancreas, spleen, stomach, gallbladder, kidneys, large intestine, small intestine, urinary bladder, and urethra. Page 14 Page 15 Figure 1.3 Organ Systems of the Body There are 11 body systems: integumentary, skeletal, muscular, lymphatic, respiratory, digestive, nervous, endocrine, cardiovascular, urinary, and reproductive.  CLINICAL IMPACT Cadavers and the Law The study of human bodies is the foundation of medical education, and for much of history, anatomists have used the bodies of people who have died, called cadavers, for these studies. However, historically, public sentiment has made it difficult for anatomists to obtain human bodies for dissection. In the early 1800s, the benefits of human dissection for training physicians had become very apparent, and the need for cadavers increased beyond the ability to acquire them legally. Thus arose the resurrectionists, or body snatchers. For a fee and no questions asked, they removed bodies from graves and provided them to medical schools. Because the bodies were not easy to obtain and were not always in the best condition, two enterprising men named William Burke and William Hare went one step further. Over a period of time, they murdered seventeen people in Scotland and sold their bodies to a medical school. When discovered, Hare testified against Burke and went free. Burke was convicted, hanged, and publicly dissected. Discovery of Burke’s activities so outraged the public that sensible laws regulating the acquisition of cadavers were soon passed, and this dark chapter in the history of anatomy was closed. Today, in the United States, it is quite simple to donate your body for scientific study. The Uniform Anatomical Gift Act allows individuals to donate their organs or entire cadaver by putting a notation on their driver’s license. You need only to contact a medical school or private agency to file the forms that give them the rights to your cadaver. Once the donor dies, the family of the deceased usually pays only the transportation costs for the remains. After dissection, the body is cremated, and the cremains can be returned to the family. Page 16 Throughout this text book, each Systems Pathology essay presents a specific disease state and considers how this affects the interactions of the organ systems. 6 Organism Level An organism is any living thing considered as a whole, whether composed of one cell, such as a bacterium, or of trillions of cells, such as a human. The human organism is a network of organ systems that are mutually dependent upon one another. 1.3 CHARACTERISTICS OF LIFE  Learning Outcome After reading this section, you should be able to A. List and define six characteristics of life. Humans are organisms sharing characteristics with other organisms. The most important common feature of all organisms is life. This textbook recognizes six essential characteristics of life: 1. Organization refers to the specific interrelationships among the individual parts of an organism, and how those parts interact to perform specific functions. Living things are highly organized. All organisms are composed of one or more cells. In turn, cellular function depends on the precise organization of large molecules. Disruption of this organized state can result in loss of functions. 2. Metabolism (meh-TAB-oh-lizm) is the ability to use energy to perform other vital functions, such as growth, movement, and reproduction. Human cells possess specialized proteins that can break down food molecules to use as a source of energy. 3. Responsiveness is an organism’s ability to sense changes in the external or internal environment and adjust to those changes. Responses include actions such as moving toward food or water and moving away from danger or poor environmental conditions such as extreme cold or heat. Organisms can also make adjustments that maintain their internal environment. For example, if our body temperature rises, sweat glands produce sweat, which can lower body temperature down to the normal range. 4. Growth refers to an increase in the size or number of cells, which produces an overall enlargement in all or part of an organism, cell size, or the amount of substance surrounding cells. For example, bones grow when the number of bone cells increases and the bone cells become surrounded by mineralized materials. 5. Development includes the changes an organism undergoes through time, beginning with fertilization and ending at death. Development usually involves growth, but it also involves differentiation. Differentiation involves changes in a cell’s structure and function from an immature, generalized state to a mature, specialized state. For example, following fertilization, immature cells differentiate to become specific types of cells, such as skin, bone, muscle, or nerve cells. These differentiated cells form tissues and organs. 6. Reproduction is the formation of new cells or new organisms. Reproduction of cells allows for growth and development. Formation of new organisms prevents extinction of species. 1.4 HOMEOSTASIS  Learning Outcomes After reading this section, you should be able to A. Define homeostasis, and explain why it is important for proper body function. B. Describe a negative-feedback mechanism and give an example. C. Describe a positive-feedback mechanism and give an example. Homeostasis (hoh-mee-oh-STAY-sis; homeo-, the same; -stasis, to stop) is the maintenance of a relatively constant environment within the body. To achieve homeostasis, the body must actively regulate body conditions that are constantly changing. As our bodies undergo their everyday processes, we are continuously exposed to new conditions, both internally and externally. Changes in our environmental conditions, such as moving into hot or cold outdoor temperatures, can result in a change in our body temperature. Body temperature is one of our body’s variables. These changes in body conditions are called variables because their values are not constant. For cells to function normally, the volume, temperature, and chemical content of the cells’ environment must be maintained within a narrow range. Body temperature is a variable that increases when you are too hot and decreases when you are too cold. The homeostatic mechanisms that maintain normal body temperature include sweating or shivering to maintain body temperature near an ideal normal value, or set point (figure 1.4). Most homeostatic mechanisms are regulated by the nervous system or the endocrine system. Note that homeostatic mechanisms are not able to maintain body temperature precisely at the set point. Instead, body temperature increases and decreases slightly around the set point, producing a normal range of values. As long as body temperatures remain within this normal range, homeostasis is maintained. Keep in mind that these fluctuations are minimal. Note in figure 1.4a that the normal body temperature range is no more than 1°F above or below normal. Our average body temperature is 98.6°F. Just as your home’s thermostat does not keep the air temperature at exactly 75°F at all times, your body’s temperature is not kept at exactly 98.6°F at all times. PROCESS Figure PROCESS Figure 1.4 Negative- and Positive-Feedback Mechanisms (a) Homeostasis is the maintenance of a variable around an ideal normal value, or set point. The value of the variable fluctuates around the set point to establish a normal range of values. (b) Negative feedback is one of the mechanisms by which homeostasis is maintained. Receptors signal the control center, which regulates the action of the effectors. In the example, body temperature is too high, so sweating occurs. Negative feedback stops the sweating when the body temperature returns to normal. (c) Positive feedback is also a type of mechanism that works to maintain homeostasis. Receptors signal the control center that the cervix is being stretched, which results in the control center sending signals to increase the contractions of the uterus. This cycle continues, becoming stronger over time until the baby is born.  Occasionally an individual will not be able to produce sweat and can overheat, potentially suffering a heat stroke. Within the context of the body temperature homeostatic mechanism, where might the disruption occur? Propose at least three ways sweat production might be inhibited when the body temperature rises above the set point. The organ systems help keep the body’s internal environment relatively constant. For example, the digestive, respiratory, cardiovascular, and urinary systems function together so that each cell in the body receives adequate oxygen and nutrients while also ensuring that waste products do not accumulate to a toxic level. If body fluids deviate from homeostasis, body cells do not function normally and can even die. Disease disrupts homeostasis and sometimes results in death. Modern medicine attempts to understand disturbances in homeostasis and works to reestablish a normal range of values. Negative Feedback Most systems of the body are regulated by negative-feedback mechanisms which maintain homeostasis. In everyday terms, the word negative is used to mean “bad” or “undesirable.” In this context, negative means “to decrease.” Negative feedback is when any deviation from the set point is made smaller or is resisted. Negative feedback does not prevent variation but maintains variation within a normal range. The maintenance of normal body temperature is an example of a negative- feedback mechanism. Normal body temperature is critical to our health because it allows molecules and enzymes to keep their normal shape so they can function optimally. An optimal body temperature prevents molecules from being permanently destroyed. Picture the change in appearance of egg whites as they are cooked: the egg whites change from a transparent liquid to a white solid because the heat changes the shape of the egg white molecules. Similarly, if the body is exposed to extreme heat, the shape of the molecules in the body could change, which would eventually prevent them from functioning normally. Page 17 Most negative-feedback mechanisms have three components: (1) A receptor (ree-SEP-tor), which monitors the value of a variable, such as body temperature, by detecting stimuli; (2) a control center, such as part of the brain, which determines the set point for the variable and receives input from the receptor about the variable; and (3) an effector (ee-FEK-ter), such as the sweat glands, which can adjust the value of the variable when directed by the control center, usually back toward the set point. A changed variable is a stimulus because it initiates a homeostatic mechanism. Several negative- feedback mechanisms regulate body temperature, and they are described more fully in chapter 5. Figure 1.4b demonstrates the steps in the negative-feedback regulation of body temperature if it becomes too high. Normal body temperature depends on the coordination of multiple structures, which are regulated by the control center (the hypothalamus). ❶ Receptors in the skin monitor body temperature. If body temperature rises, the receptors send a message to the control center. ❷ The control center compares the value of the variable against the set point. ❸ If a response is necessary, the control center will stimulate the effectors, the sweat glands, to produce their response, which is secretion of sweat. ❹ Once the value of the variable has returned to the set point, the effectors do not receive any more information from the control center. For body temperature, this means that secretion of sweat stops. These same steps can be used to help you answer the Learn to Apply It question at the beginning of this chapter. Page 18 Often there is more than one effector for a particular homeostatic mechanism. In these cases the control center must coordinate the effectors’ responses. For example, cooling the body involves not only the production of sweat by the sweat glands, but also the action of the blood vessels to alter blood flow to the skin. Once body temperature has returned to normal, the effectors stop. This is the hallmark of negative feedback—effectors stop their response once the variable has returned to its set point. They do not produce an indefinite response (figure 1.5). Page 19 Homeostasis Figure 1.5 Negative-Feedback Control of Body Temperature Throughout this book, all homeostasis figures have the same format as shown here. The changes caused by the increase of a variable outside the normal range are shown in the upper, green boxes, and the changes caused by a decrease are shown in the lower, red boxes. To help you learn how to interpret homeostasis figures, some of the steps in this figure are numbered. (1) Body temperature is within its normal range. (2) Body temperature increases outside the normal range, which causes homeostasis to be disturbed. (3) The body temperature control center in the brain responds to the change in body temperature. (4) The control center causes sweat glands to produce sweat and blood vessels in the skin to dilate. (5) These changes cause body temperature to decrease. (6) Body temperature returns to its normal range, and homeostasis is restored. Observe the responses to a decrease in body temperature outside its normal range by following the lower, red arrows.  Apply It 1 What effect would swimming in cool water have on body temperature regulation mechanisms? What would happen if a negative-feedback mechanism did not return the value of a variable, such as body temperature, to its normal range? Page 20 Positive Feedback Positive-feedback mechanisms occur when a response to the original stimulus results in the deviation from the set point becoming even greater. In other words, positive means “increase.” At times, this type of response is required to return to homeostasis. For example, during blood loss, a chemical responsible for blood clot formation, called thrombin, stimulates production of even more thrombin. In this way, a disruption in homeostasis is resolved through a positive-feedback mechanism. What prevents the entire vascular system from clotting? The clot formation process is self-limiting. Eventually, the components needed to form a clot will be depleted in the damaged area and more clot material cannot be formed. As shown in figure 1.4c, birth is another example of a normally occurring positive-feedback mechanism. ❶ Near the end of pregnancy, the baby’s large size stretches the uterus. ❷ This stretching, especially around the opening of the uterus, stimulates contractions of the uterine muscles. ❸ The uterine contractions push the baby against the opening of the uterus, which results in additional stretching. ❹ This positive-feedback sequence ends when the baby is delivered from the uterus and the stretching stimulus is eliminated. Two basic principles about homeostatic mechanisms to remember are that (1) many disease states result from the failure of negative-feedback mechanisms to maintain homeostasis, and (2) some positive-feedback mechanisms can be detrimental instead of helpful. One example of a detrimental positive-feedback mechanism is inadequate delivery of blood to cardiac (heart) muscle. Contraction of cardiac muscle generates blood pressure. The heart pumps blood to itself through a system of blood vessels on the outside of the heart. Just as with other tissues, blood pressure must be maintained to ensure adequate delivery of blood to the cardiac muscle. Following extreme blood loss, such as a severe cut on the body, not enough blood is delivered to cardiac muscle. As a result, the heart cannot function normally. The heart pumps less blood, which causes the blood pressure to drop even further, which causes even less blood to be delivered to the heart. The process continues until the heart stops beating, and death results. In this example, we see the deviation from the heart-rate set point becoming larger and larger—this is the hallmark of positive feedback. Thus, if blood loss is severe, negative-feedback mechanisms may not be able to maintain homeostasis and the positive feedback of ever-decreasing blood pressure can develop. On the other hand, following a moderate amount of blood loss (e.g., after donating a pint of blood), negative-feedback mechanisms result in an increase in heart rate that restores blood pressure. Apply It 2 Is the sensation of thirst associated with a negative- or a positive-feedback mechanism? Explain. (Hint: What is being regulated when you become thirsty?) 1.5 TERMINOLOGY AND THE BODY PLAN Learning Outcomes After reading this section, you should be able to A. Describe a person in anatomical position. B. Define the directional terms for the human body, and use them to locate specific body structures. C. Know the terms for the parts and regions of the body. D. Name and describe the three major planes of the body and the body organs. E. Name and describe the three major ways to cut an organ. F. Describe the major trunk cavities and their divisions. G. Describe the serous membranes, their locations, and their functions. As you study anatomy and physiology, you will be learning many new words. Knowing the etymology (ET-ee-MOL-oh-jee) of these words can make learning them easy and fun. Most anatomical terms are derived from Latin or Greek. For example, foramen is a Latin word for “hole,” and magnum means “large.” The foramen magnum is therefore a large hole in the skull (through which the spinal cord continues from the brain). Words are often modified by adding a prefix or suffix. For example, the suffix -itis means an inflammation, so appendicitis is an inflammation of the appendix. As new terms are introduced in this text, their meanings are often explained. The glossary and the list of word roots, prefixes, and suffixes also provide additional information about the new terms. Body Positions Anatomical position refers to a person standing upright with the face directed forward, the upper limbs hanging to the sides, and the palms of the hands facing forward (figure 1.6). A person is supine when lying face upward and prone when lying face downward. Page 21 Figure 1.6 Directional Terms All directional terms are in relation to the body in the anatomical position: a person standing erect with the face directed forward, the arms hanging to the sides, and the palms of the hands facing forward. ©Eric Wise In anatomical position, the head is above the feet, but if a person were to do a handstand, the head would be closer to the ground than the feet were. However, we would still refer to the head as being “above” the feet because the point of reference for anatomical structures is their position on the body, not the position of the body compared to the earth. Directional Terms Directional terms describe parts of the body relative to each other (figure 1.6 and table 1.1). It is important to become familiar with these directional terms as soon as possible because you will see them repeatedly throughout the text. Right and left are used as directional terms in anatomical terminology. In anatomy, the term superior means above, and the term inferior means below. Anterior is used for “in front of” and the term posterior is used for “behind.” TABLE 1.1 Directional Terms for the Human Body Term Etymology Definition* Example Right Toward the body’s right The right ear side Left Toward the body’s left The left ear side Inferior Lower Below The nose is i