Which structure is NOT part of the central nervous system?

The structure that is not part of the central nervous system is the nerves. The central nervous system (CNS) consists of the brain and spinal cord. The brain controls most functions of the body and mind, while the spinal cord transmits signals between the brain and the rest of the body.

Nerves, on the other hand, are part of the peripheral nervous system (PNS), which is responsible for relaying information from the CNS to various parts of the body, as well as bringing sensory information to the CNS. The PNS includes all the nerves that branch out from the spinal cord and brain to reach the limbs and organs. Therefore, while the brain, cerebellum, and spinal cord are integral components of the CNS, nerves serve a different function and belong to the PNS.