Difference Between Autonomic and Somatic Nervous Systems
By Rebecca Rodriguez - April 23, 2022

The nervous system is one of the body’s most complex systems due to its function as a constant relay of information both within and without the body through the efforts of stimuli-carrying nerves. It is thus functionally divided into two broad categories: The central nervous system, made up of the brain and spinal cord, are the final points of stimuli interpretation and impulse conveyance. In contrast, the peripheral nervous system is responsible for both transmissions. The peripheral nervous system is, in turn, split into two functional divisions known as the autonomic and somatic nervous systems.

Table Summary

Autonomic Nervous System (ANS)Somatic Nervous System (SNS)
Controlled by the Sympathetic and Parasympathetic Nervous Systems.It is controlled by the cranial and spinal nerves.
It requires two efferent neurons and ganglia.Works with only one efferent neuron
It regulates Cardiac Muscles, Smooth Muscles, and Glands.It regulates Skeletal muscles.
Involuntary actionMostly voluntary action.
Involves excitatory and inhibitory neurotransmittersIt involves excitatory neurotransmitters.
Radiologist assessing CT brain scan

Getty Images / Image Source / Andrew Brookes


The Autonomic Nervous system refers to managing the impulses and stimuli that occur within the body’s internal organs. This refers to the heart beating, contraction, dilation of blood vessels, the stomach contraction during digestion, and many more.

The Somatic Nervous System sees the regulation of impulses and stimuli that act on the body’s skeletal muscles. It transmits motor and sensory signals from and to the central nervous system. These are the muscles required for movement and are therefore mostly voluntary movements.


The Automatic Nervous System controls all involuntary movements, while the Somatic Nervous System is responsible for primarily voluntary actions. Illness such as Parkinson’s disease and Lupus may affect the proper functioning of the ANS, while the SNS can be affected by physical trauma or diseases such as multiple sclerosis (MS).