A beginner needs to be introduced to basic concepts and elementary principles used in Human Anatomy and Physiology. An attempt has been made to explore the subject in a simple language and in a lucid manner as possible, keeping in mind the intellectual level of the students. Illustrations, tables, graphs, flow charts, diagrams and photographs have been used frequently to make the topic clear and easily understandable. It is sincerely hoped that both the students and teachers will find it useful, and present attempt will prove its significance.