What is the study of body function called?

The study of body function is known as physiology. This field focuses on understanding how different systems within the body work, interact, and maintain homeostasis. It examines various physiological processes, including how organs function, how biochemical pathways operate, and how various systems respond to internal and external changes.

In contrast, histology pertains to the study of microscopic structures of tissues, while anatomy focuses on the physical structure of the body and its parts. Pathology deals with the study of diseases and their effects on body function. Thus, physiology stands out as the discipline specifically dedicated to exploring the normal functions of living organisms, making it the correct answer for the question.