2. Somatosensation Somatosensation include awareness of touch, temperature, and pain. There are several types of touch receptors, including Meissner’s corpuscles, Ruffini endings, Merkel’s disks, free nerve endings, and Pacinian corpuscles.
3. Somatosensation Meissner’scorpuscles respond to sudden displacements of the skin and low-frequency vibrations such as fluttering. Ruffiniendings respond to stretch of the skin. Merkel’sdisks respond to forces that occur at a tangent (angle) across the skin. Free nerve endings respond to pain, warmth, and cold. Paciniancorpuscles respond to sudden displacements of the skin and high-frequency vibrations.
4. Somatosensation Information about touch enters the brain through the cranial nerves (nerves in the head) and the spinal nerves (nerves below the head). Each skin area that has particular nerves responding to touch is associated with a single spinal nerve called a dermatome. The information about touch is sent along a very specific pathway to the brain.
5. Somatosensation When information about touch gets to the brain, the information goes first through the thalamus and is routed to the somatosensory cortex, located in the parietal lobe. There are two strips in this area that respond mostly to touch and two strips that respond to deep pressure and movement of the joints and muscles.