MEISSNER'S CORPUSCLE

'Meissner's corpuscles' (or 'tactile corpuscles') are a type of mechanoreceptor, responsible for sensitivity to light touch.

Contents

Location

Structure

Age Related Changes

Function

Comparison with other receptors

Eponym

Additional images

External links

Location

They are distributed throughout the skin, but concentrated in areas especially sensitive to light touch, such as the fingertips, palms, soles, lips, tongue, face and the skin of the male and female genitals.
They are primarily located just beneath the epidermis within the dermal papillae.

Structure

Meissner's corpuscles are encapsulated 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, 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 (ie: while physically reforming) causes another volley of action potentials 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 corpuscles (the only other type of phasic tactile mechanoreceptor), which are located deeper in the dermis, and some free nerve endings.
Also, Meissner's corpuscles do not detect pain; this is signalled exclusively by free nerve endings.

Eponym

Meissner's corpuscles were discovered by the anatomist Georg Meissner (1829-1905).

Additional images

External links

★ Donald L. Rubbelke D.A. Tissues of the Human Body: An Introduction. McGraw-Hill. 1999 Meissner's and Pacinian corpuscles

★ Dawn A. Tamarkin, Ph.D. Anatomy and Physiology Unit 15 Vision and Somatic Senses: Touch and Pressure

★ S Gilman. Joint position sense and vibration sense: anatomical organisation and assessment. ''Journal of Neurology Neurosurgery and Psychiatry'' 2002;73:473-477

★ - "Integument pigmented skin, Meissner's corpuscles "

★ - "Meissner's Tactile Corpuscle"

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★ Histology at rutgers.eud

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