This book is about human anatomy and physiology--the structure and function of the body. It is meant to provide you with a foundation for later study in pathology, health care, exercise physiology, and other fields related to health and fitness. Even an introductory course in anatomy and physiology requires the assimilation of a large amount of information, but the effort is very rewarding. You will find your knowledge of the body not only fascinating but of highly practical value. In addition to preparing you for a possible career in health science, the knowledge you gain can serve you well in managing your own health. If you have not already done so, please read the Preface to Students, which includes tips for the most effective use of this book and its companion materials in the enjoyment and mastery of this subject.