In this accessible and informative textbook, George Dallas Lind provides an introduction to the study of human physiology. He explains the functions of the major organ systems, as well as the principles of cellular biology and molecular biology. This book is an excellent resource for anyone beginning to study physiology, or for anyone interested in the workings of the human body. This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.