This book presents a concise and focused examination of the essential concepts in physiology. Through a streamlined and easy-to-follow hierarchical outline format, it guides students through the basic physiologic principles. After an introductory chapter on general concepts and cellular physiology, the book reviews the normal and abnormal functions of the major organ systems. The outline is enhanced with discussions of relevant clinical correlations and an extensive and original illustration program that visually conveys the essential information and promotes retention of the material. Each chapter concludes with USMLE-type questions in clinical vignette format to help students assess their understanding of the concepts.