What are the subdivisions of the nervous system?

Nervous system. In general terms, the central nervous system (CNS) is made up of the brain & spinal cord. The peripheral ns includes the cranial nerves, spinal nerves, & all others outside of the cns. Functionally the autonomic ns involves essentially involuntary actions. The sympathetic ns is the 'fight or flight' emergency system & parasympathetic ns is the rest & digest system. They work together.