PHYSIOLOGY

Medical physiology is one of the defining courses of the first year of medical school. One might argue that is the most "important" course in the first-year curriculum, for obvious reasons. It is also one of the most challenging. Finding a textbook is often difficult, as many professors prefer to use their own lecture notes, suggesting a textbook as an additional reference and giving little guidance on textbooks that may serve as additional references. Linda Costanzo's Physiology has been a favorite resource for medical students nationwide. Despite vast differences in presentation style and method, basic principles and problem solving are elements of every physiology course. As such, Physiology has been well-received because the text focuses on essential concepts in a focused, highly lucid fashion. In addition, Costanzo presents clinical scenarios in each chapter, tying in problem solving and pathophysiology. The second edition of the textbook continues with the strengths of the original, but offers more breadth in each chapter. Her chapter on cardiovascular physiology expands on the relationships between the inotropic and chronotropic effects of the ANS on the heart, takes a closer look at the cardiac action potential, and has an improved discussion of peripheral and central chemoreceptors in the control of blood pressure. In addition, new problem solving sections are presented, one of which includes a helpful demonstration of the effects of parallel resistance. Pulmonary physiology is one of the most challenging areas of physiology. Costanzo acknowledges this by enhancing her discussion of lung compliance, compliance curves, and the pathophysiological changes in obstructive and restrictive lung disease. Topics such as right-to-left shunts, V/Q mismatch, and the A-a gradient are all enlivened by the addition of new graphics and tables. The chapter on renal physiology is improved with an expanded discussion of the sympathetic nervous system, the reninangiotensin-aldosterone axis, prostaglandins and dopamine on renal blood flow. New graphics pertaining to sodium homeostasis are also included. Her chapter of endocrine physiology now offers a clear explanation of the dexamethasone suppression test and the T3 resin uptake test, along with the clinical advantages of each test. Parathyroid pathophysiology is expanded with new discussions of humoral hypercalcemia of malignancy and familial hypocalciuric hypercalcemia. Students of physiology will find continued comfort in the second edition of Physiology as a companion to their first year explorations and beyond. It is a didactic, "friendly," teaching textbook. Indeed, the text presents the key elements of medical physiology in an exquisitely clear and concise manner. Linda Costanzo's giftedness as an educator is apparent to any student who uses this invaluable resource during the pre-clinical years.