Find the best physiology lessons, classes, and instructors at HeyKiki and learn all about physiology. Physiology's orgins go back to ancient Greece. It is the study of living things and how their systems functions. This includes, cells, organelles, organs, and muscles. Physiologists study how these different parts of a living thing plays an important part, how it responds and changes to the environment, and overall, how they meet the needs of the living organism.