Tactile corpuscle

Structure

Tactile corpuscles are encapsulated myelinated nerve endings, surrounded by Schwann cells. The encapsulation consists of flattened supportive cells arranged as horizontal lamellae surrounded by a connective tissue capsule. The corpuscle is 30–140 μm in length and 40–60 μm in diameter. A single nerve fiber meanders between the lamellae and throughout the corpuscle.

Location

They are distributed on various areas of the skin, but concentrated in areas especially sensitive to light touch, such as the fingers, lips and male prepuce. More specifically, they are primarily located in glabrous skin just beneath the epidermis within the dermal papillae.

Comparison with other receptors

Function

Tactile corpuscles are rapidly adapting mechanoreceptors. They are sensitive to shape and textural changes in exploratory and discriminatory touch. Their acute sensitivity provides the neural basis for reading Braille text. Because of their superficial location in the dermis, these corpuscles are particularly sensitive to touch and vibrations, but for the same reasons, they are limited in their detection because they can only signal that something is touching the skin. They also contribute to two-point discrimination, allowing the skin to detect stimuli at closely spaced points.

Any physical deformation of the corpuscle will cause sodium ions to enter it, creating an action potential in the corpuscle's nerve fiber. Since they are rapidly adapting or phasic, the action potentials generated quickly decrease and eventually cease (this is the reason one stops "feeling" one's clothes).

If the stimulus is removed, the corpuscle regains its shape and while doing so (i.e.: while physically reforming) causes another volley of action potentials to be generated.

Additional images

Skin.png|"Meissner's corpuscle" labeled at upper right Image:Gray940.png|Diagrammatic sectional view of the skin. Image:WVSOM Meissner's corpuslce.JPG|light micrograph

References

Sources

References

1. "Georg Meissner".
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3. "Meissner's Corpuscles {{!}} AnatomyBox".
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5. (November 2004). "Meissner corpuscles and somatosensory acuity: the prehensile appendages of primates and elephants.". The Anatomical Record Part A: Discoveries in Molecular, Cellular, and Evolutionary Biology.
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8. "Nervous system - Touch". BBC.
9. (12 June 2021). "Sensory innervation of the human male prepuce: Meissner's corpuscles predominate". Journal of Anatomy.
10. Winkelmann, R. K.. (1959-01-21). "The Erogenous Zones: Their Nerve Supply and Significance". Proceedings of the Staff Meetings of the Mayo Clinic.
11. (January 1981). "Tactile sensitivity as a function of age". Journal of Gerontology.
12. (2016). "Neuroscience : Exploring the Brain". Wolters Kluwer.
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