Physiology is the branch of biology that studies how living organisms function. It looks at the various systems within the body, such as the nervous system, circulatory system, and respiratory system, to understand how they work together to maintain life. By examining processes like breathing, digestion, and circulation, physiologists can learn how the body responds to different conditions and challenges. This field is essential for understanding health and disease. For example, studying physiology helps researchers develop treatments for illnesses by revealing how the body normally operates and what goes wrong when someone is sick. Overall, physiology provides crucial insights into the mechanics of life.