What are the two main parts of the nervous system?

The two main parts of the nervous system are the central nervous system and the peripheral nervous system. The central nervous system consists of the spinal cord and the brain, which contains 100 billion nerve cells. The peripheral nervous system is broken down into the somatic and autonomic nervous systems.

In the somatic nervous system, sensory information is sent to the central nervous system by the peripheral nerve fibers. The autonomic nervous system controls muscles in the vital organs and glands. The sympathetic nervous system, parasympathetic nervous system and enteric nervous system are the three main parts of the autonomic nervous system.