The twenty-first century, much like the last one, will probably be characterized by the rapid accumulation of new knowledge at an ever-increasing rate. Modern research approaches using molecular techniques, new analytical instruments, advanced imaging systems, relatively non-invasive surgical techniques, and others will continue to support the development of new knowledge and new applications of that knowledge.

In spite of all the changes that have occurred, some things remain the same. Students need good basic science courses that help them learn essential information, understand how new knowledge is gained, and think critically with the information they have learned. Excellent teachers who explain concepts and inspire students are essential. Good textbooks that support the efforts of teachers to provide clear explanations and exercises designed to cultivate the development of critical thinking are vital educational resources.

Essentials of Anatomy and Physiology is designed to help students develop a solid, basic understanding of essential concepts in anatomy and physiology without an encylopedic presentation of detail. It is not possible to pack all that is known into a book of this type. However, it is important that a textbook provide enough information to allow students to understand basic concepts and to make reasonable predictions and analyses. Great care has been taken to select critically important information and present it in a way that maximizes understanding. In the current edition, we have continued the tradition of combining clear and accurate descriptions of anatomy, precise explanations of how structures function, and examples of how structures work together to maintain life. We have provided explanations of how the systems respond to physical activity, disease, and aging, with a special focus on how regulatory systems control functions so that homeostasis is maintained. We have included timely and interesting examples to demonstrate the application of knowledge in a clinical context. For example, enough information is presented to allow students to understand the normal structure and function of the heart, understand how the heart responds to age-related changes, and predict the consequences of blood loss or heart attack. Also, enough information is included to help students understand the effects of transfusion, treatments that reduce damage to heart muscle, and treatments that help the heart continue to pump blood.

It is essential for students in the twenty-first century to develop a working knowledge of key concepts. To cultivate this knowledge, Essentials of Anatomy and Physiology utilizes a carefully crafted combination of clearly written text, comprehensive tables, and informative artwork to explain anatomical structures and their functions. In addition to a clear and concise presentation of fact, we also incorporate a strong emphasis on critical thinking activities to help students apply their knowledge in a meaningful way. This framework of educational tools helps students study and remember concepts, but also challenges them to make appropriate predictions and analyses.