What term describes the study of how the nervous system functions?

The study of how the nervous system functions is referred to as neurophysiology. This specialized branch of physiology focuses on the characteristics and operations of nerve cells and neural circuits, exploring how signals are transmitted throughout the nervous system. Neurophysiology incorporates various aspects of both anatomy and physiology to understand how the nervous system processes information, regulates bodily functions, and interacts with other systems.

Histology, on the other hand, deals with the study of tissues at a microscopic level, while cytology focuses on the study of individual cells. Physiology is a broader term that encompasses the study of the functions of all biological systems, not specifically the nervous system. In contrast, neurophysiology’s specific concentration on the nervous system's functioning sets it apart as the correct answer in this context.