Physiology is the study of the processes of living systems. It is one of the cornerstones of the study and practice of medicine. Rather than focussing on physical structures, as is done in anatomy, physiology looks at body functions at the molecular level and the interactions between different physical parts of the body (such as the working of joints). In medicine, the focus is often on the structure and function of the organs.
Most medical specialties focus primarily on physiology rather than anatomy, such as psychiatry, neurology, opthamology, cardiology, gastroenterology, dermatology, nephrology, immunology, endocrinology, as well as several others.