Merkel's skin receptors are slowly adapting skin receptors that detect pressure, texture, and low frequency vibration and can be appropriately evaluated by static two-point discrimination. Merkel's disk receptors adapt slowly and sense sustained pressure, texture, and low-frequency vibrations.
Szabo et al state in their review that static and moving two point discrimination are best to initially evaluate innervation density for both quickly and slowly adapting fibers. Vibratory moving 2 point discrimination is best for evaluation of quickly adapting fibers.
Meissner corpuscle, a rapidly adapting sensory receptor, is very sensitive to touch. Pacinian corpuscles are ovoid in shape, measuring approximately 1 mm in length. They respond to high-frequency vibration and rapid indentations of the skin. Ruffini corpuscles are slowly adapting receptors that detect stretching of the skin.
Illustration A demonstrates Meissner's corpuscles (A), Pacinian corpuscles (B), Merkel's receptor (C), free nerve ending (D), and Ruffini corpuscles (E). Illustration B displays the function and location of the receptors.
Manske PR (ed): Hand Surgery Update. Englewood, CO, American Society for Surgery of the Hand, 1994, p 223
Szabo RM, Madison M. Carpal tunnel syndrome. Orthop Clin North Am. 1992 Jan;23(1):103-9. Review.
PMID:1729659 (Link to Abstract)