Which two main divisions comprise the nervous system?

The nervous system is primarily divided into two main divisions: the central nervous system (CNS) and the peripheral nervous system (PNS). The central nervous system consists of the brain and spinal cord, serving as the main control center for processing information and coordinating responses. The peripheral nervous system includes all the nerves that branch out from the spinal cord and connect to the rest of the body, facilitating communication between the CNS and limbs or organs.

This division is fundamental for understanding how different components of the nervous system interact and how they contribute to overall function. Other options, such as the somatic and autonomic nervous systems, are actually subdivisions of the peripheral nervous system; the cerebral cortex and brainstem are parts of the central nervous system; and the sympathetic and parasympathetic systems are components of the autonomic nervous system, which itself is a part of the peripheral nervous system. Hence, the choice that identifies the primary divisions of the nervous system itself is indeed the central and peripheral nervous systems.