Somatic nervous system

Last revised by Craig Hacking on 19 Oct 2022

The somatic nervous system (SNS) is a subdivision of the peripheral nervous system which provides innervation to the somatic structures of the body, that is the parts excluding the viscera, smooth muscle, and glands.

The SNS is distributed throughout the body through somatosensory neurons within spinal nerves that innervate specific sclerotomes, dermatomes and myotomes. These are defined embryological as arising from specifc somites.

The SNS includes:

  • sensory (afferent) fibers from sensory receptors for the sensation of touch, pain, temperature, and position (vestibular and proprioception)

  • motor (efferent) fibers to skeletal (voluntary) muscles

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