Divisions of the nervous system

What it is

The nervous system has two parts: the central nervous system, which is the brain and the spinal cord, and the peripheral nervous system.

The peripheral nervous system itself has two:

• The autonomic nervous system, which communicates with internal organs and glands. Under it sit the sympathetic division, the arousing one, and the parasympathetic division, the calming one.
• The somatic nervous system, which communicates with sense organs and voluntary muscles. Under it sit the sensory or afferent nervous system, which is sensory input, and the motor or efferent nervous system, which is motor output.