Preface

We have been teaching anatomy and physiology and related courses for many years. We have also explored the literature and carried out objective investigations in our classes to help us understand how students learn. This extensive experience has allowed us to develop a picture of what we believe works to help anatomy and physiology students learn effectively. We have used this information and the feedback from hundreds of reviewers, who also teach anatomy and physiology, to develop Essentials of Anatomy and Physiology. The professionals at McGraw-Hill have provided tremendous encouragement and support in this process. Their expertise and commitment to excellence has helped us develop this exceptional learning aid for your students.

Human anatomy and physiology courses present exciting and tremendous challenges to both students and teachers. The acquisition of basic anatomical and physiological facts is essential to the study of anatomy and physiology, but it is also important for students to develop ability to solve practical, real-life problems related to the knowledge they have acquired. It is not possible for students to learn all of the details of anatomy and physiology that are known. Selecting the most important information to provide a solid understanding of anatomy and physiology and to prepare students to solve problems effectively are major challenges for teachers and for authors.

We have written each edition of Essentials of Anatomy and Physiology with the same major intention: To help students learn basic anatomy and physiology. We chose to present the major concepts that provide a current understanding of the subject. We present the information in a readable form that seeks to explain in such a way that concepts may be truly understood rather than simply memorized. Written explanations of structures and functions are coupled with illustrations that reinforce the concepts and explanations.

As in previous editions of Essentials of Anatomy and Physiology, we emphasize the relationship between structure and function and homeostasis. Just as the structure of a hammer makes it well suited for the function of pounding nails, the structure of specific cells, tissues, and organs within the body allows them to perform their specific functions effectively. For example, the structure of proteins and their arrangement in muscle cells makes the contraction of muscle possible, and bone cells surround themselves with a mineralized matrix that provides strength and support.

Homeostasis is necessary for the survival of the human body. This book emphasizes the importance of mechanisms that maintain homeostasis. Because failure of these mechanisms also illustrates how they work, examples of pathological conditions resulting in dysfunction, disease, and possibly death are presented. Changes in response to physical activity and aging are also included to illustrate how homeostatic mechanisms work. Consideration of pathology, exercise, and aging adds relevance and interest, makes the material more meaningful, and enhances the background of students who plan to pursue health-related careers.

Essentials of Anatomy and Physiology also delivers a strong emphasis on critical thinking. Critical thinking exercises are interwoven throughout the text to help students use the information they have learned and to appreciate the relevance of the information in real-life situations. The numerous examples and questions in the text are used to help students learn to think critically. It is not possible to memorize how all organs and organ systems respond to all types of stimuli. However, it is very possible to learn the basic structure and function of cells, organs, and organ systems and then use that knowledge to predict responses to many different types of stimuli, including those that result from exercise, aging, and disease.

The order of chapters in the text is fairly traditional and is similar to that found in many other texts at this level. However, the content of the chapters and the organization of the information within each chapter is, in many ways, unique. The content in this text is organized in what we feel is the best framework for helping students develop a working knowledge of the subject matter. Although the chapters build on one another, and can be taught effectively in the sequence in which they are presented, care has been taken to make chapters sufficiently complete to allow them to be covered in a different order as well.

Major Themes of Anatomy and Physiology Chapter 1 presents major themes in anatomy and physiology, and the definitions and subcategories of anatomy and physiology. It also illustrates the hierarchy of organization of human structures and the basic characteristics of life. Chapter 1 emphasizes that humans are composed of trillions of cells, carry out metabolism, respond to stimuli, grow, differentiate, and reproduce. The concept of homeostasis is illustrated through discussion and example, and the related concepts of feedback control--both positive and negative and their consequences are presented. Homeostasis figures are introduced, and this model is used throughout the text to illustrate how systems function to maintain a constant internal environment. The terminology used to describe directional references, planes, body regions, body cavities, and serous membranes is presented in Chapter 1 and is applied consistently throughout the remainder of the book.

Chemistry Chapter 2 presents the essential concepts in chemistry that are necessary for understanding the concepts of anatomy and physiology presented in this text. Students who have taken a chemistry class may be able to skip this chapter, but most students are likely to benefit from reading it. General terms like matter, mass, and weight are defined. The concepts of elements and atoms are introduced and basic atomic structure is presented. The basic behavior of electrons and the principles of ionic, covalent, and hydrogen bonding are described. Definitions of molecules and compounds, and some characteristics of their behavior are presented. Major characteristics of chemical reactions are described. Energy relationships of chemical reactions, and the rates of chemical reactions are explained. Acids, bases, the pH scale, inorganic chemistry, and organic chemistry are defined. The characteristics of important organic chemicals such as carbohydrates, lipids, proteins, and nucleic acids are described and the functions of enzymes are presented.

Cell Structures and Their Functions Chapter 3 introduces essential information about the cell. A list of cell functions and a brief description of cell structure are presented. The structure and function of membranes and organelles are introduced. Movement through the cell membrane, osmosis, filtration, and mediated transport mechanisms are described. Cell metabolism and the organelles involved and protein synthesis are explained. The roles of DNA and RNA in transcription and translation are emphasized. Cell division (mitosis) and meiosis are described, and the importance of cell differentiation is also presented.

Tissues, Glands, and Membranes Chapter 4 defines tissues and the four primary tissue types, with emphasis on their functional characteristics. Major categories of epithelial, connective, muscle, and nervous tissue are described and illustrated with example figures. Categories of membranes and their locations are presented. Inflammation and tissue repair are described.

Support and Movement Chapters 5, 6, and 7 describe the integumentary, skeletal, and muscular systems. Chapter 5 presents the functions of the integumentary system. The structure of the hypodermis and skin, including the epidermis and dermis are described, as are accessory structures of the skin such as hair, glands, and nails. The role of the skin in sensations, vitamin D production, temperature regulation, and excretion is explained. Aging, burns, skin cancer and other pathologies are described. Chapter 6 presents the structure and functions of bones. Types of bone are identified based on both shape and histology, and bone growth and repair are emphasized. The anatomy of the appendicular and axial skeleton is described, summarized in tables, and presented in figures. Articulations, or joints, are classified and examples of the joints are described, with emphasis on synovial joints. Chapter 7 describes the microscopic structure of muscle tissue and the processes of contraction and relaxation. This chapter also introduces membrane potentials, action potentials, and basic physiological characteristics of skeletal muscle. The anatomy of the major skeletal muscles of the body is described, presented in tables, and illustrated. Smooth and cardiac muscle are also introduced, but more briefly than skeletal muscle. These muscle types are described in later chapters in more detail.

Systems of Integration and Control Chapters 8, 9, and 10 present the nervous and endocrine systems. Chapter 8 introduces the basic functions and divisions of the nervous system. The cells of the nervous system are described and membrane potentials and action potentials are explained. Unlike many texts, enough information is presented to allow students to understand the role of the resting membrane potential and factors that affect action potentials. The structure and function of the synapse are presented, as well as the mechanisms by which neurotransmitters influence postsynaptic neurons. Neuronal interactions are illustrated in the presentation of functions accomplished by reflexes. Chapter 8 also introduces neuronal circuits and the structure and function of the major components of the brain and spinal cord. The peripheral nervous system and its subdivisions are defined, and the structural and functional characteristics of the autonomic nervous system are presented. A variety of clinical examples are presented in this chapter to help students understand how the components of the nervous system involved in each pathology function. Chapter 9 describes the functions of sensory organs and provides adequate information to allow students to understand how sensory organs work and the consequences of abnormalities that affect the sensory organs or pathways that transmit and integrate sensory information. Pain is described in enough detail so students can understand its functions, as well as some techniques used to modulate pain sensations. Care has been taken to present the special senses of olfaction, taste, vision, hearing, and balance. The objective, as in the remainder of the text, is to present enough information about the structure and function of organs involved to allow students to understand how they work and predict how they respond to stimuli. Examples are provided, including clinical examples. Chapter 10 introduces the basic principles of the endocrine system and describes the major endocrine organs and the role they play in the control of functions. Characteristics of chemical signals and the means by which they interact with target cells are described. Molecular biology has provided information that makes it easier to understand how chemical signals produce responses in specific cells. The endocrine glands, the hormones secreted by the endocrine glands, and the effects of hormones on their target tissues are described. The mechanisms that control hormone secretion are emphasized, and the consequences of reduced secretion or over-secretion of hormones are presented.

Systems of Regulation and Maintenance Chapter 11 describes the anatomy and physiology of blood, Chapter 12 describes the anatomy and physiology of the heart, Chapter 13 presents the anatomy and physiology of blood vessels and circulation, and Chapter 14 presents the anatomy and physiology of the lymphatic system and organs involved in the immune response. The basic anatomy of structures is exceptionally well illustrated. Without providing overwhelming detail, a clear picture of the functions of the circulatory system is presented. The coverage of the regulation of the circulatory system is exceptional, and no other text presents the same concise and complete picture. It is exciting and convenient for students to develop the ability to predict responses of the circulatory system to changes and to pathologies.

Chapter 15 describes the anatomy and physiology of the respiratory system, Chapter 16 describes the anatomy and physiology of the digestive system, Chapter 17 describes nutrition, metabolism, and body temperature regulation. Chapter 18 presents the urinary system and fluid balance. These chapters aim to help students develop the ability to understand how these systems work to maintain homeostasis. The pattern of describing and illustrating the functions and structures of these systems and the mechanisms that control them is repeated throughout these chapters. Consistent emphasis on these themes helps students understand changes that occur in response to a variety of stimuli and pathologies and fosters the ability to predict changes in response to stimuli. Care has been taken to provide adequate information to help students develop analytical and predictive abilities without an overwhelming amount of detail. The essential information is described in the text and figures have been developed to clearly illustrate the functions and regulatory mechanisms specific to each system.

Reproduction and Development Chapter 19 describes and illustrates the anatomy and physiology of the male and female reproductive systems, and Chapter 20 provides basic information about development, heredity, and aging. The basics of sexual reproduction are presented and the roles of meiosis and differentiation of male and female reproductive structures are explained. Control mechanisms are emphasized, and the roles they play in the development of sperm and oocytes, the maintenance of these cells, and how reproductive structures bring these cells together and result in fertilization are explored. Puberty, reproductive cycles in adults, pregnancy, parturition, and lactation are presented. The basic mechanisms of heredity and development are also presented. Finally, appropriate for the last chapter, Chapter 20 presents many of the basic changes that occur in humans as they age.