Pacinian corpuscle - Definition

A Pacinian corpuscle is a structure that functions as a mechanoreceptor. The pacinian corpuscle was named after its discoverer, Italian anatomist Filippo Pacini. The pacinian corpuscle is ovoid shaped, approximately 1 mm in length and consists of 20 to 60 concentric lamellae composed of fibrous connective tissue and fibroblasts, separated by gelatinous material. The lamellae are very thin and flat modified Schwann cells. An afferent unmyelinated nerve ending is at the center of the corpuscle. In the center is the inner bulb, a fluid filled cavity with a single nerve fiber. They function as mechanoreceptors, detecting gross pressure changes and vibrations. The entire corpuscle is wrapped by a layer of connective tissue.

Any deformation in the corpuscle causes nerve impulses to generate. They are especially susceptible to vibrations. They are found in mesenteries, especially the pancreas and subcutaneous tissue, especially near joints.

It is thought that they respond to high velocity changes in joint position.

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