Which component is NOT part of the central nervous system?

The component identified as not part of the central nervous system is indeed the plexus of nerves outside the brain and spinal cord. The central nervous system (CNS) is composed of the brain and spinal cord.

The cerebral hemispheres, spinal cord, and brainstem are all integral parts of the CNS, responsible for processing information and coordinating responses throughout the body. The plexus of nerves, however, refers to networks of nerves located outside the CNS, specifically categorized under the peripheral nervous system (PNS).

The distinction between the CNS and PNS is key in neuroscience; the CNS serves as the control center, while the PNS connects the CNS to the limbs and organs. Understanding this separation is crucial in the study of neural communication processes and the overall structural organization of the nervous system.