Thoroughly updated for its Fourth Edition, BRS Physiology is an excellent aid for students preparing for the USMLE Step 1. The book concisely reviews key physiological principles and includes clinical correlations throughout to emphasize connections between basic physiology and clinical medicine. Numerous illustrations, tables, and flow charts help students visualize material quickly and aid in long-term retention. End-of-chapter USMLE-style questions and a comprehensive end-of-book exam test the student's problem-solving skills, and clearly explained answers guide the student through the correct steps in reasoning. This edition features increased coverage of pathophysiology, new questions, and a new two-color design and artwork.