Physiology is the branch of biology that deals with the study of the functions and processes of living organisms. It encompasses a wide range of topics, from the functions of cells and tissues to the workings of organ systems and the regulation of bodily functions. Physiologists study how organisms work and adapt to changes in their environment, including the regulation of body temperature, the digestion of food, the movement of muscles, and the processing of sensory information. Understanding physiology is essential for health professionals, athletes, and individuals seeking to maintain optimal health and well-being.