The somatic nervous system is the division of the peripheral nervous system which consists of sensory neurons conveying information to the central nervous system, and motor neurons sending information from the central nervous system to the skeletal muscles.

The autonomic nervous system is often generally described as the non-voluntary division of the peripheral nervous system, controlling peripheral organs and mobilizing energy. The autonomic nervous system is sub-divided into the sympathetic (energy mobilization) and parasympathetic (relaxation) nervous systems, as well as the enteric nervous system.