What distinguishes central nervous system from the peripheral nervous system?

The central nervous system (CNS) is distinguished from the peripheral nervous system (PNS) primarily by its composition and function. The CNS comprises the brain and spinal cord, which serve as the main control center for processing information and coordinating responses in the body. This structural distinction is critical because the CNS is responsible for higher brain functions, including thought, memory, and decision-making, as well as basic bodily functions like reflexes.

While the other options discuss functions traditionally related to nervous system activity, they do not highlight the defining structural aspect of the CNS. For instance, although the CNS does play a role in managing sensory input and muscle contractions indirectly, these functions are also shared with the PNS, which serves as the communication pathway between the CNS and the rest of the body. Similarly, metabolic regulation involves many organ systems and is not exclusively linked to either nervous system division. Thus, the defining feature of the CNS being the brain and spinal cord solidifies its identity and sets it apart from the PNS.