Anatomy and Physiology 2e

Citation

Betts, J. G., Young, K. A., Wise, J. A., Johnson, E., Poe, B., Kruse, D. H., Korol, O., Johnson, J. E., Womble, M., & DeSaix, P. (2022). Anatomy and Physiology 2e (2nd ed.). OpenStax. Free official edition: https://openstax.org/details/books/anatomy-and-physiology-2e

Chapter Summary

The book's 28 chapters are organized into six units that follow the usual two-semester sequence. Because of the number of chapters, closely related chapters are grouped below by unit, with the book's chapter titles kept exactly.

Chapters 1–4: An Introduction to the Human Body; The Chemical Level of Organization; The Cellular Level of Organization; The Tissue Level of Organization

Unit 1 lays the foundation. Chapter 1 distinguishes anatomy from physiology, describes the six levels of structural organization, the functions and requirements of human life, homeostasis and negative and positive feedback, anatomical terminology (positions, regions, planes and cavities) and medical imaging. Chapter 2 reviews atoms, bonds, reactions, water, acids, bases and buffers, and the organic molecules of the body. Chapter 3 covers the cell membrane and transport, organelles, the nucleus and DNA replication, protein synthesis, the cell cycle and cell differentiation, including stem cells and cancer. Chapter 4 introduces the four tissue types and tissue membranes, then epithelial, connective, muscle and nervous tissue, ending with tissue injury, repair and ageing.

Chapters 5–11: The Integumentary System; Bone Tissue and the Skeletal System; The Axial Skeleton; The Appendicular Skeleton; Joints; Muscle Tissue; The Muscular System

Unit 2 covers support and movement. The integumentary chapter describes the epidermal layers, dermis and hypodermis, accessory structures such as hair, nails and glands, the skin's functions, and burns, cancers and other disorders. The skeletal chapters explain bone functions, classification, structure, formation and fracture repair, the influence of exercise, nutrition and hormones, and calcium homeostasis, followed by a bone-by-bone tour of the skull, vertebral column and thoracic cage and of the girdles and limbs, with notes on their embryonic development. The joints chapter classifies fibrous, cartilaginous and synovial joints, names body movements and examines selected joints such as the shoulder and knee. Chapter 10 explains skeletal, cardiac and smooth muscle, including the sliding filament mechanism, neural control of tension, fibre types and exercise, and Chapter 11 introduces lever systems, the naming of muscles and the actions of the major axial and appendicular muscles.

Chapters 12–17: The Nervous System and Nervous Tissue; Anatomy of the Nervous System; The Somatic Nervous System; The Autonomic Nervous System; The Neurological Exam; The Endocrine System

Unit 3 deals with regulation and control. Chapter 12 introduces the divisions of the nervous system, neurons and glia, membrane potentials, the action potential and synaptic communication. Chapter 13 relates embryonic development to adult brain regions, then describes the central nervous system, its circulation and protective coverings, and the peripheral nervous system. Chapter 14 treats sensory perception, including the special senses integrated here, central processing and motor responses; Chapter 15 covers the sympathetic and parasympathetic divisions, autonomic reflexes, central control and drugs that affect the autonomic system. Chapter 16 takes an unusual clinical approach, explaining nervous system function through the five parts of the neurological exam (mental status, cranial nerve, sensory, motor, and coordination and gait). Chapter 17 surveys hormones and their mechanisms, the hypothalamus and pituitary, thyroid, parathyroid, adrenal and pineal glands, gonadal and placental hormones, the endocrine pancreas and organs with secondary endocrine functions.

Chapters 18–21: The Cardiovascular System: Blood; The Cardiovascular System: The Heart; The Cardiovascular System: Blood Vessels and Circulation; The Lymphatic and Immune System

Unit 4 covers fluids and transport. The blood chapter describes plasma and the formed elements, haemopoiesis, erythrocytes, leukocytes and platelets, haemostasis and blood typing. The heart chapter covers anatomy, the cardiac circuits, cardiac muscle and the conduction system, the cardiac cycle, cardiac output and its regulation, and heart development. The blood vessel chapter explains vessel structure, blood flow, pressure and resistance, capillary exchange, homeostatic regulation, the major circulatory pathways and fetal circulation. The final chapter of the unit describes lymphatic anatomy, barrier and innate defences, T and B lymphocytes and antibodies, immune responses to pathogens, immune disorders, transplantation and cancer immunology.

Chapters 22–26: The Respiratory System; The Digestive System; Metabolism and Nutrition; The Urinary System; Fluid, Electrolyte, and Acid-Base Balance

Unit 5 examines exchange with the environment and internal maintenance. The respiratory chapter follows conducting and respiratory zones, the lungs, the mechanics of breathing, gas exchange and gas transport, and adaptations such as exercise and altitude. The digestive chapter covers the alimentary canal and accessory organs, the processes and regulation of digestion, and chemical digestion and absorption. Chapter 24 explains catabolic and anabolic reactions, carbohydrate, lipid and protein metabolism, absorptive and postabsorptive states, energy and heat balance, and nutrition. The urinary chapter moves from the characteristics of urine through kidney anatomy and nephron microanatomy to filtration, tubular reabsorption, regulation of renal blood flow and endocrine control. Chapter 26 ties these together through fluid compartments, water and electrolyte balance, buffers and acid–base disorders.

Chapters 27–28: The Reproductive System; Development and Inheritance

Unit 6 closes the book. Chapter 27, revised for the second edition with terms such as the "testicular" and "ovarian" reproductive systems, covers gametogenesis, reproductive anatomy and hormonal regulation, and the development of the reproductive systems. Chapter 28 follows fertilization, embryonic and fetal development, changes during pregnancy, labour and birth, the newborn's adjustments after birth, lactation and patterns of inheritance.

Key Concepts

Chapters 1–4: Levels of Organization

• Homeostasis and feedback: maintenance of internal stability, mainly by negative feedback, with positive feedback amplifying certain processes such as childbirth.
• Levels of organization: chemical, cellular, tissue, organ, organ system and organism.
• Membrane transport: passive diffusion and osmosis versus active, energy-requiring transport.
• Four tissue types: epithelial, connective, muscle and nervous tissue.

Chapters 5–11: Support and Movement

• Layers of the skin: epidermis, dermis and hypodermis, each with distinct functions.
• Bone remodelling and calcium homeostasis: continual formation and resorption of bone, regulated by hormones and linked to blood calcium.
• Joint classification: structural (fibrous, cartilaginous, synovial) and functional (synarthrosis, amphiarthrosis, diarthrosis) categories.
• Sliding filament model: muscle contraction by actin and myosin filaments sliding past each other.

Chapters 12–17: Regulation, Integration, and Control

• Action potential: the electrical signal of neurons, produced by voltage-gated ion channels.
• Sympathetic and parasympathetic divisions: autonomic outputs for "fight or flight" and for rest and digestion.
• Localization of function: the principle used in the neurological exam to infer where damage lies from what function is lost.
• Hormone mechanisms: lipid-soluble hormones act through intracellular receptors; water-soluble hormones act through membrane receptors and second messengers.

Chapters 18–21: Fluids and Transport

• Formed elements and plasma: the cellular and fluid components of blood.
• Cardiac output: heart rate multiplied by stroke volume, adjusted by preload, contractility and afterload.
• Capillary exchange: movement of fluid driven by hydrostatic and osmotic pressures.
• Innate and adaptive immunity: rapid nonspecific defence versus specific responses by T and B lymphocytes with memory.

Chapters 22–26: Energy, Maintenance, and Environmental Exchange

• Ventilation and gas exchange: pressure-driven air movement and diffusion of oxygen and carbon dioxide across the respiratory membrane.
• Digestive processes: ingestion, propulsion, mechanical and chemical digestion, absorption and defecation.
• Nephron function: filtration, tubular reabsorption and secretion that produce urine.
• Acid–base balance: control of pH by buffers, respiration and the kidneys.

Chapters 27–28: Human Development and the Continuity of Life

• Gametogenesis: meiotic production of sperm and oocytes under hypothalamic and pituitary control.
• Embryonic and fetal development: from fertilization and implantation through organogenesis and growth.
• Patterns of inheritance: dominant, recessive and sex-linked inheritance and their prediction.

Critical Analysis

Strengths

• Complete coverage of the two-semester sequence. The six units follow the scope and sequence of most two-semester courses, from chemistry and cells to reproduction and inheritance, with homeostasis used as a unifying theme across the system chapters.
• Distinctive pedagogical choices. The preface highlights that the special senses are integrated into the somatic nervous system chapter and that Chapter 16 teaches nervous system function through the neurological exam, an approach that links anatomy to clinical reasoning. The art programme uses mostly black-line illustrations with colour reserved for key structures, and many Interactive Links lead to University of Michigan WebScope micrographs, simulations and videos.
• Clinical and career relevance. Recurring features (Homeostatic Imbalances, Disorders of the..., Aging and the..., Everyday Connection, Career Connection) cover topics from decompression sickness and cancer to cardiac tamponade, sleep apnea and the Apgar score, and introduce allied-health careers such as phlebotomy and physical therapy.
• Inclusive second-edition revision. The 2e changes focus on accuracy in distinctions related to sex and gender (with guidance from Gender-Inclusive Biology), more representative illustrations, and photographs of conditions that present differently on different skin tones.

Limitations

• Very long. At about 1,350 pages, the book is a reference as much as a course text; self-learners need to select sections, especially within the detailed skeletal and muscular chapters.
• Uneven physiological depth. Some physiological mechanisms (for example cardiac and renal regulation) are explained thoroughly, while quantitative treatment and experimental evidence are limited, so students heading for medical physiology will need a more analytical text.
• Limited answers for self-study. The preface states that answers to odd-numbered Interactive Link, Review and Critical Thinking questions are in the Student Solution Manual, with even-numbered answers available only to instructors.
• Human-centred scope. The book covers human anatomy and physiology only, without comparative or plant physiology, which matters in a course that also lists animal and plant physiology texts.

Where It Fits in the Course

In a physiology and anatomy course this is the free introductory core text for human anatomy and physiology. Waugh and Grant's Ross & Wilson Anatomy and Physiology in Health and Illness, also written for newcomers to the subject, is generally described as a shorter, clinically oriented introduction often used in nursing; either can serve as a first text, with OpenStax offering more detail and more features. Silverthorn's Human Physiology: An Integrated Approach (an undergraduate physiology textbook) concentrates on physiological mechanisms and integration, and Boron and Boulpaep's Medical Physiology is a detailed medical-school text; both are best read after the corresponding OpenStax chapters.

The other two listed books widen the scope beyond humans: Taiz and colleagues' Plant Physiology and Development (an upper-level plant biology text) and Hill, Cavanaugh and Anderson's Animal Physiology (a comparative text) deal with plants and comparative animal physiology. OpenStax Anatomy and Physiology 2e provides the human baseline against which comparative material can be understood, but does not replace those texts.

How to Use This Book

The book is designed for the two-semester anatomy and physiology sequence, typically taken by pre-nursing and allied-health students. No college-level biology or chemistry is assumed, since Chapters 2–4 review the necessary chemistry and cell biology.

A common plan is Units 1–3 (Chapters 1–17) in the first semester and Units 4–6 (Chapters 18–28) in the second. Read Chapter 1's terminology and homeostasis sections carefully, since later chapters rely on them. Begin each chapter with the chapter objectives, study the black-line figures alongside the text, and follow the Interactive Links, especially the WebScope micrographs for histology and the animations for physiological processes. Use the Chapter Review summaries for revision, answer the Interactive Link, Review and Critical Thinking questions (checking odd-numbered answers in the Student Solution Manual), and read the Disorders and Homeostatic Imbalances features to connect normal function with disease. For anatomy-heavy chapters such as 7, 8 and 11, practise labelling figures rather than rereading.

Edition and Sources

This guide is based on Anatomy and Physiology 2e (OpenStax, original publication 2022), read in the official free PDF downloaded from https://openstax.org/details/books/anatomy-and-physiology-2e (current printing, colour paperback ISBN 978-1-711494-06-7). It draws on the preface (coverage and scope by unit, second-edition changes, features, art programme, answer policy), the full table of contents, and for all 28 chapters the chapter objectives, every section heading, the titles of all feature boxes, and the Chapter Review section summaries.