IMS: Cardiopulmonary System is based on the understanding that the study of physiology is conceptual in nature. As a result, this book carefully and methodically develops the most important concepts underlying the functions of the heart, lungs, and circulation (ie, the cardiopulmonary system) and demonstrates the integrated nature of the entire system. By taking this approach, medical students will find this text helpful not only in understanding the most important elements of cardiopulmonary physiology but also in providing a useful review of the heart, lungs and circulation in preparation for Step 1 of the USMLE. A unigue tool, the "cycle diagram," is used throughout the book to present the key concepts of homeostasis. One of the major messages of any cycle diagram is that no single organ or organ focuses on detailing how the organs of the cardiopulmonary system function as an integrated whole. Once mastered, the cycle diagrams become an affective mechanism by which to summarise the way almost any system functions.