Tactile corpuscle
Meissner's corpuscles or Meissner 's corpuscles - named after its discoverer, the German anatomist and physiologist Georg Meissner - are pressure receptors of the inguinal skin. They primarily are found in the fingertip, but not in hairy areas of skin ( hairy skin ).
The elongated oval Meissner's corpuscles belongs to the group of lamellar bodies with no perineural capsule. The corpuscle is about 100 - 150μm long and 40 - 70μm wide and is supplied by 1-7 dendritic axons, which are wound helically and between which stacks of Schwann cells are located. It is pseudounipolar neurons.
The Meissner's corpuscles respond to pressure changes. They are among the rapidly adapting (RA ) mechanoreceptors, so only fire during the change of stimulus intensity. They are speed sensors that signal the impressions of the skin as a pressure change, but adapt to the new, lower position of the imprinting object, and therefore emit any signals other more. The adaptation to a constant pressure stimulus is very fast, within 50-500 ms instead.
RA sensors of the monkeys hand reacted in tests already on surveys of 4 microns, which illustrates the particular importance of these sensors to the touch of the man who when reading braille plays an important role, for example. The sense of touch of the skin is mediated by other mechanosensors that are specialized to certain stimuli: as the Merkel cells respond to pressure intensity, Ruffini 's corpuscles to distension and the Pacinian lamellar to vibration.
Meissner 's corpuscles are located in the papillary dermis of hairless skin, especially in large numbers they are present in the fingertips. They are also used in the subepithelial connective tissue of the penis, anus and oral mucosa. In the hairy skin lacks the Meissner's corpuscles, here are hair follicles sensors that are similar.
More images
A Meissner's corpuscles (tip of black pointer ) in the light microscope. The localization in the papillary dermis of the corium is easy to recognize.