The Guyton and Hall Physiology Review, by Dr. John E. Hall, is an ideal way to prepare for the USMLE Step I. More than 1,000 board-style questions, as many as 30% revised for this edition, test your knowledge of the most essential, need-to-know concepts in physiology. Review the physiology of all major body systems, with emphasis on system interaction, homeostasis, and pathophysiology, and master a large amount of information in an abbreviated time. Focus on all of the essential information you need to know for the physiology portion of the USMLE Step I. Reinforce your understanding and visualize physiologic principles with enhanced color figures and well- illustrated line diagrams.