Which of the following is NOT a function of the nervous system?

The function of the nervous system encompasses a variety of roles, primarily involving the coordination and control of bodily functions. It is responsible for processing sensory information and directing responses to both internal and external stimuli. Directing bodily defenses against external stimuli, regulating heart rate, and controlling respiratory rates are all essential functions of the nervous system, where it interacts directly with other systems.

However, the release of heat from the muscular system does not fall under the primary functions of the nervous system. While the nervous system can influence muscle activity and thereby affect heat production during movement, it does not directly regulate heat release. Instead, this is more associated with homeostatic mechanisms involving the integumentary and circulatory systems, which manage temperature regulation through processes such as sweating and blood flow adjustments.

Thus, the correct answer highlights a function that is less about nervous system control and more about other systems working to maintain body temperature and manage heat dissipation.