Book excerpt: The study of the biological, science, and mechanical functions that make up human life is known as physiology. The study of human science and physiology is the oldest and most intriguing area of scientific study. Physiology's crowning achievement is the way it unifies the individual functions played by the body's cells, tissues, as well as organs into a coherent whole: the human body. Indeed, the human body is much more than the sum of its parts, and life relies upon its total function, not merely on the function of the individual body parts in independence from the others. Following in the footsteps of world of Anatomy and Physiology. this book is aimed towards newcomers to the discipline of Physiology. Students interested in pursuing a career in medicine, dentistry, nursing, or other health-needed principles, or in furthering their care at the graduate level in biological and health sciences, will find this physiology very basic. It may also be helpful for doctors and other medical professionals who want to refresh their memories on the fundamentals of human disease pathophysiology. Many physiology principles may now be described in terminology of the molecular and physical sciences, rather than as a set of distinct and unexplainable biological occurrences, thanks to possible developments in molecular and cellular physiology. The field of physiology is heavily reliant on laboratory-based basic research. Some physiologists focus on studying individual cells or proteins, while others may investigate how cells work together to produce complex tissues, organs, and