Primary divisions of the nervous system

The nervous system is composed of the central nervous system (CNS) and the peripheral nervous system (PNS). Such divisions are contiguous both anatomically and functionally. The CNS involves both the brain and spinal cord. The peripheral nervous system is all else; namely nerve trunks going between the CNS and the periphery, and the networks of nerve cells with the supporting glia in organs throughout the body. The PNS has three sections, the somatic, autonomic, and the enteric nervous system.