What is the study of functions of the human body called?

The correct choice is physiology, which is the branch of biology that focuses on the functions and mechanisms of the human body and its systems. It encompasses how various organs and systems work together to maintain homeostasis and respond to internal and external changes. Understanding physiology is crucial in fields such as medicine and veterinary sciences, as it provides insights into how body systems operate normally and how they may be affected by disease or injury.

Anatomy, while closely related, specifically refers to the structure of the body and its parts rather than their functions. Pathology, on the other hand, deals with the study of diseases, including their causes, development, and effects on the body. Biochemistry examines the chemical processes and substances that occur within living organisms but does not focus primarily on bodily functions as physiology does. Thus, physiology effectively captures the essence of studying the functions of the human body.