Chapter 1: Organization of the Body
New illustrations, tables, and a reading titled “Organs for Transplant” introduce the student to the human body. The discussion of negative feedback now includes temperature control as an example and also includes a discussion of positive feedback, as requested by reviewers.

Chapter 2: Chemistry of Life
This chapter has been reorganized and rewritten to help students understand fundamental chemistry concepts. Carbohydrates, lipids, proteins, and nucleic acids each have their own major section.

Chapter 3: Cell Structure and Function
Cellular Organization, Crossing the Plasma Membrane, and The Cell Cycle are clearly defined as chapter sections. Tables 3.1, 3.2, and all art are new to this edition. The Medical Focus reading, “Dehydration and Water Intoxication” is also new to this edition.

Chapter 4: Body Tissues and Membranes
Each type of tissue now has its own major section. In addition to body membranes, connections between cells and different types of glands are discussed in respective sections. Art and tables have been revised for this chapter.

Chapter 5: The Integumentary System
Section 5.5., Homeostasis, is new to this edition. It shows how the various functions of the skin assist the body in maintaining homeostasis. Also discussed are hyperthermia and hypothermia, which occur when homeostasis has been overcome. The section is accompanied by an updated Human Systems Work Together illustration.

Chapter 6: The Skeletal System
New illustrations, each of which is on the same or a facing page to its reference, much improve this chapter. More information is given about each bone and joint discussed. The chapter ends with a review of the many ways the skeletal system helps maintain homeostasis.

Chapter 7: The Muscular System
The first two illustrations in this chapter are new: The first shows the three types of muscles, and the second describes the connective tissue coverings within and around a skeletal muscle. Instructors and students will appreciate the new in-depth discussion of the sources of energy for muscle contraction, which is also accompanied by a new illustration.

Chapter 8: The Nervous System
This chapter was rewritten. In particular, the discussion of the cerebrum has been expanded to include not only the various lobes but also the areas within these lobes. The somatic system of the peripheral nervous system is now clearly defined, and the spinal reflex has been moved to this section. New illustrations support improved discussions of all aspects of the nervous system.

Chapter 9: The Sensory System
Types of senses, rather than types of receptors, are now used to organize this chapter. The discussions of the anatomy and physiology of the eye and ear are better organized, with an emphasis on how information regarding vision and sound is generated and transmitted to the brain. The sense of equilibrium is now divided into rotational and gravitational equilibrium.

Chapter 10: The Endocrine System
An overview of the endocrine glands now precedes an improved discussion of each gland. A new illustration shows how the adrenal medulla and the adrenal cortex are involved in short-term and long-term stress, respectively. Other new illustrations pertain to regulation of blood calcium, regulation of blood pressure, Addison disease, and Cushing syndrome. The chapter also includes a discussion of chemical signals in general and how hormones affect cellular metabolism.

Chapter 11: Blood
A detailed description of the composition and function of blood now opens the chapter. There follows a more comprehensive look at the formed elements. The section on platelets centers around hemostasis, including coagulation. The transport function of blood is illustrated by considering capillary exchange. The last section of the chapter, Blood Typing and Transfusions, is supported by new art that clearly illustrates blood types and agglutination.

Chapter 12: The Cardiovascular System
An overview of the cardiovascular system, supported by an illustration, offers a much-improved introduction to the chapter, which has been reorganized into five parts: the anatomy of the heart, the physiology of the heart, the anatomy of blood vessels, the physiology of circulation, and circulatory routes. A better discussion of cardiac output and peripheral resistance improves the presentation of the chapter.

Chapter 13: The Lymphatic System and Body Defenses
As requested by reviewers, the lymphatic organs are now divided into those that are primary and those that are secondary. The discussion of specific immunity is much improved by new illustrations depicting the action of B cells and T cells. A new reading on emerging diseases modernizes the chapter.

Chapter 14: The Respiratory System
An improved Table 14.1, which includes a description of the respiratory organs, adds to the discussion of the respiratory system. The respiratory membrane is better described and is accompanied by a new illustration. The section entitled Mechanism of Breathing is better organized so that regulation of breathing rates now has its own subsection. Following reviewers’ suggestions, the chapter is more student friendly because gas exchange and transport no longer require a knowledge of partial pressures. All readings are new or extensively revised.

Chapter 15: The Digestive System
New illustrations of stomach and small intestine anatomy add to the improved and extended discussion of these topics. Chemical digestion now benefits by having its own separate section. The Medical Focus reading “Human Teeth” has been moved to a logical location early in the chapter. Liver structure, function, and disorders are more logically and thoroughly presented. The chapter ends with an added discussion of three eating disorders: obesity, bulimia nervosa, and anorexia nervosa.

Chapter 16: The Urinary System and Excretion
The functions of the urinary system are discussed more thoroughly than in the fourth edition. The discussion of a nephron has been improved by the addition of micrographs. The role of the loop of the nephron and various hormones in water reabsorption is better explained, and the topic of acidbase balance has been expanded to discuss all the ways the body can adjust the pH of the blood. The chapter ends with a discussion of treatments for kidney failure.

Chapter 17: The Reproductive System
The topic of meiosis has been moved to this chapter so that spermatogenesis and oogenesis can be better understood by students. Coverage of the reproductive organs has been improved by the inclusion of both sagittal and posterior views of the systems. Following reviewers’ suggestions, the menstrual (instead of the ovarian and uterine cycles) is discussed. New Health Focuses are provided on endocrine-disrupting contaminants, shower checks for cancer, and preventing transmission of STDs.

Chapter 18: Human Development and Birth
The addition of new figures depicting fertilization, extraembryonic membranes, and the primary germ layers improves this chapter. Extensive revision is obvious due to the addition of new readings entitled “Therapeutic Cloning” and “Preventing Birth Defects.” A discussion of the development of male and female organs has been added, and the chapter ends with a new and extended discussion of the effects of pregnancy on the mother.

Chapter 19: Human Genetics
Aside from having all sections revised and updated, the chapter uses cystic fibrosis to show the connection between a genetic disorder and the function of a protein and to illustrate the levels of genetic counseling, from doing a pedigree to performing a preimplantation genetic study. The chapter ends with a Medical Focus outlining the future benefits from the modern field of genomics.