Chapter 1: We introduce a new presentation of homeostasis and negative feedback in the form of homeostasis figures. We use homeostasis figures throughout the text to illustrate negative feedback mechanisms that function to maintain homeostasis. These figures appear in a form that allows students to systematically follow how deviations from a set point trigger specific mechanisms that function to cause the deviations to be reversed. A new section describing the characteristics of life has been added.

We have added a description of homeostatic mechanisms using the concepts of receptors, control centers, and effectors. In addition, the concepts of variation around a set point producing a normal range of values is introduced. New illustrations of negative and positive feedback and the introduction of the homeostasis illustrations used throughout the remainder of the text.

Chapter 2: The chemistry chapter has been rewritten to be consistent with the presentations found in modern introductory chemistry texts, including a discussion of the differences between molecules and compounds, the formation of covalent and ionic bonds, and the effect of dissociation on molecules, covalent compounds, and ionic compounds. A new section was added on energy and chemical reactions and the significance of ATP production and breakdown within cells.

Chapter 3: The sections on transport processes, receptors and membrane channels are rewritten to be consistent with current data and made to be consistent with descriptions in the other chapters of the book.

Chapter 4: The organization of the tissue illustrations has been changed. We have improved the transition from macroscopic to microscopic structure and establish a convenient and consistent labeling organization to make patterns easy to recognize.

Chapter 5: A new chapter opening description summarizes the functions of the integumentary system. This format is used in the other chapters that introduce systems. There is an improved discussion and illustration of the transfer of melanin from melanocytes to other cells in the epidermis. A Systems Pathology essay on burns has been added to the end of the chapter.

Chapter 6: A new figure has been added to improve the presentation of bone repair. Insets have been added to figures to help students appreciate the orientation of individual bones in the whole skeleton. A Systems Pathology essay on osteoporosis has been added at the end of the chapter.

Chapter 7: Labels on muscle figures and tables have been reorganized to make cross-referencing the information in tables and figures easier. A System Pathology essay on muscular dystrophy has been added at the end of the chapter.

Chapter 8: New figures have been added to provide a clear representation of resting membrane potentials and action potentials. New figures representing the functional characteristics of the cerebellum have been added. A System Pathology essay on stroke has been added at the end of the chapter.

Chapter 9: New figures have been added to illustrate the optic radiations.

Chapter 10: A new section has been included to present simple models of how chemical signals, such as hormones, interact with receptors at either the membrane or within the cell, to produce a response. Homeostasis figures have been added to summarize how hormones regulate functions so that homeostasis is maintained. A System Pathology essay on hyperthyroidism has been added to the end of the chapter.

Chapter 11: A new section on the functions of blood has been added. Revised discussion on platelet plug formation and an introduction to integrins is included. A new discussion of disseminated intravascular coagulation is included.

Chapter 12 and 13: Figures in these chapters have been revised to illustrate the location of the heart in the thoracic cavity, the layers of the heart and blood vessels, the anatomy of blood vessels, and to improve consistency in style. Homeostasis figures have been added to present a simple and clear explanation of heart and blood pressure regulation. A System Pathology essay has been added on Myocardial infarctions.

Chapter 14: A revised discussion and new illustrations of antigen recognition, helper T cell proliferation, and the activation of B cells has been added. A new overview illustration of the relationships between innate, antibody-mediated, and cell-mediated immunity was included. A new section on immunotherapy was added. A new Systems Pathology essay on systemic lupus erythematosus has been added to the end of the chapter.

Chapter 15: A new introduction summarizing the functions of the respiratory system has been added. A revised discussion and new illustrations of the tracheobronchial tree have been included. A new section on the lymphatic supply of the respiratory system has been added. A revised discussion and new illustrations of the mechanics of breathing and the pressure changes that cause air flow in the lungs have been included. A revised and expanded presentation of the neural control of respiration that is consistent with modern concepts of respiratory control has been included. A revised discussion of the effects of exercise on respiration and a new section on respiratory adaptations to exercise has been included. A new Systems Pathology essay on asthma has been added at the end of the chapter.

Chapter 16: Figures have been changed to create a more consistent art style. A new section, with figures, on digestion, absorption, and transport have been added. A System Pathology essay has been added on Diarrhea.

Chapter 17: We added a new section on the role of enzymes in regulating metabolism. We revised the discussion on and created new illustrations of anaerobic and aerobic respiration, the electron transport chain, and lipid and protein metabolism. We introduce a new section and illustration of the absorptive and postabsorptive state. We present a new illustration of heat exchange and a new homeostasis illustration depicting temperature regulation.

Chapter 18: New figures have been added to clearly illustrate the nephron and its functions. Homeostasis figures have been added to illustrate the role of the kidney in maintaining homeostasis, as well as the means by which water and electrolytes are regulated. A System Pathology essay on kidney failure has been added.

Chapter 19: Figures have been changed to make clear the structural and functional characteristics of reproductive structures. A System Pathology essay on benign uterine tumors has been added.

Chapter 20: Figures have been changed to create a more consistent art style. The genetics section has been rewritten and expanded.