Which portion of the nervous system controls unconscious body activities?

The autonomic nervous system is responsible for controlling unconscious body activities, such as the regulation of heart rate, digestion, respiratory rate, and other involuntary functions. This system operates automatically and is subdivided into the sympathetic and parasympathetic nervous systems, which balance the body's response to stress and relaxation.

In contrast, the somatic nervous system is involved in voluntary movements and the transmission of sensory information from the body to the central nervous system. The central nervous system, which includes the brain and spinal cord, processes the information but does not directly control bodily functions. Finally, the peripheral nervous system encompasses all the nerves outside the central nervous system, linking it to the rest of the body, but it does not specifically dictate unconscious activities as the autonomic system does. Thus, the choice emphasizing the autonomic nervous system aligns perfectly with its role in managing involuntary functions.