Meissner's corpuscle 767242 206764121 2008-04-19T21:27:49Z Solar-Poseidon 5175715 Tagged as unreferenced article {{Unreferenced|date=April 2008}} {{Infobox Anatomy | Name = {{PAGENAME}} | Latin = corpusculum tactus | GraySubject = 233 | GrayPage = 1061 | Image = Skin.jpg | Caption = "Sensory nerve endings for touch" labeled at upper right.) | Image2 = Gray936.png | Caption2 = Papilla of the hand, treated with acetic acid. Magnified 350 times.<BR><BR>A. Side view of a papilla of the hand. <BR>a. Cortical layer. <BR>b. Tactile corpuscle. <BR>c. Small nerve of the papilla, with neurolemma. <BR>d. Its two nervous fibers running with spiral coils around the tactile corpuscle. <BR>e. Apparent termination of one of these fibers. <BR><BR>B. A tactile papilla seen from above so as to show its transverse section. <BR>a. Cortical layer. <BR>b. Nerve fiber. <BR>c. Outer layer of the tactile body, with nuclei. <BR>d. Clear interior substance. | System = | MeshName = Mechanoreceptors | MeshNumber = A08.800.550.700.500 | DorlandsPre = c_56 | DorlandsSuf = 12261393 | }} '''Meissner's corpuscles''' (or '''tactile corpuscles''') are a type of [[mechanoreceptor]]. They are a type of [[nerve]] endings in the [[skin]] that are responsible for sensitivity to light [[touch]]. They are [[rapidly adaptive receptors]]. ==Location== They are distributed throughout the [[skin]], but concentrated in areas especially sensitive to light touch, such as the [[fingertip]]s, [[hand|palms]], [[sole (foot)|sole]]s, [[lips]], [[tongue]], [[face]] and the skin of the male and female [[sex organ|genitals]]. They are primarily located just beneath the [[epidermis (skin)|epidermis]] within the [[dermal papillae]]. ==Structure== Meissner's corpuscles are encapsulated [[myelin|unmyelinated]] [[nerve]] endings, which consist of flattened supportive cells arranged as horizontal lamellae surrounded by a [[connective tissue]] capsule. The corpuscle is between 30-140 μm in length and 40-60 μm in diameter A single nerve fiber meanders between the lamellae and throughout the corpuscle. ==Age Related Changes== The number of Meissner corpuscles per square millimeter of human skin on the fingertips drops fourfold between the ages of 12 and 50. The rate at which they are lost correlates well with the age-related loss in touch sensitivity for small probes (Thornbury and Mistretta, 1981). ==Function== Any physical deformation in the corpuscle will cause an [[action potential]] in the nerve. Since they are rapidly adapting or [[phasic receptor|phasic]], the [[action potential]]s 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 (ie: while physically reforming) causes another volley of [[action potential]]s to be generated. 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. ==Comparison with other receptors== Feelings of deep [[pressure]] (from a poke, for instance) are generated from [[Pacinian corpuscle]]s (the only other type of phasic tactile mechanoreceptor), which are located deeper in the dermis, and some [[free nerve ending]]s. Also, Meissner's corpuscles do not detect [[pain]]; this is signalled exclusively by [[free nerve ending]]s. ==Eponym== Meissner's corpuscles were discovered by the [[anatomy|anatomist]] [[Georg Meissner]] ([[1829]]-[[1905]]). ==Additional images== <gallery> Image:Gray940.png|Diagrammatic sectional view of the skin. Image:WVSOM Meissner's corpuslce.JPG|light micrograph </gallery> ==See also== ==External links== * Donald L. Rubbelke D.A. [http://www.mhhe.com/biosci/ap/histology_mh/receptor.html#pacinian Tissues of the Human Body: An Introduction. McGraw-Hill. 1999 Meissner's and Pacinian corpuscles] *Dawn A. Tamarkin, Ph.D. [http://distance.stcc.edu/AandP/AP/AP2pages/unit15/touch.htm Anatomy and Physiology Unit 15 Vision and Somatic Senses: Touch and Pressure] * S Gilman. [http://jnnp.bmjjournals.com/cgi/content/full/73/5/473 Joint position sense and vibration sense: anatomical organisation and assessment.] ''Journal of Neurology Neurosurgery and Psychiatry'' 2002;73:473-477 * {{BUHistology|08105loa}} - "Integument pigmented skin, Meissner's corpuscles " * {{AnatomyAtlasesMicroscopic|06|123}} - "Meissner's Tactile Corpuscle" * {{USCHistology|skn/c_13}} * [http://bio.rutgers.edu/~gb102/lab_5/104bm.html Histology at rutgers.eud] * {{eMedicineDictionary|tactile+corpuscle}} {{somatosensory system}} [[Category:Sensory receptors]] [[de:Meissner-Körperchen]] [[fr:Corpuscule de Meissner]] [[pt:Corpúsculo de Meissner]] [[ru:Тельце Мейснера]] [[ja:マイスナー小体]]