Somatosensory system

Touch is a crucial means of receiving information. This photo shows tactile markings identifying stairs for visually impaired people.

The somatosensory system is a subset of the sensory nervous system responsible for the perception of touch. Touch is a somatic sense in contrast to the special senses of sight, smell, taste, and hearing and balance.

The sense of touch in perceiving the environment uses special sensory receptors in the skin called cutaneous receptors. They include mechanoreceptors such as tactile corpuscles that relay information about pressure and vibration; nociceptors for pain, and thermoreceptors for temperature perception.[1]

Stimulation of the receptors activate peripheral sensory neurons that convey signals to the spinal cord that may drive a responsive reflex, and may also be conveyed to the brain for conscious perception. Somatosensory information from the face and head enter the brain via cranial nerves such as the trigeminal nerve.

The neural pathways that go to the brain are structured such that information about the location of the physical stimulus is preserved. In this way, neighboring neurons in the somatosensory cortex represent nearby locations on the skin or in the body, creating a map or sensory homunculus.

  1. ^ Sherman, Carl (August 12, 2019). "The Senses: The Somatosensory system". Dana Foundation. New York.

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