Pacinilichaampjes

Pacinilichaampjes, also known as Pacinian corpuscles, are specialized mechanoreceptors found in the skin and certain internal tissues. They were first described by the Italian anatomist Filippo Pacini in the 19th century. These receptors are particularly abundant in the glabrous skin of the fingertips, palms, and soles, and are also present in deeper layers of the dermis, around joints, tendons, and some visceral tissues.

Each Pacinian corpuscle consists of a single enlarged nerve ending encapsulated by many concentric lamellae formed from Schwann cells and connective tissue. The structure resembles an onion, with a central nerve terminal embedded in fluid-filled spaces within the lamellae. The afferent fiber is typically a large-diameter, myelinated Aβ fiber that transmits signals to the central nervous system.

Pacinian corpuscles are rapidly adapting mechanoreceptors that respond primarily to dynamic mechanical stimuli, especially high-frequency vibration and sudden changes in pressure. They are most sensitive to vibrations in the range of roughly 60 to 400 Hz and help convey information about texture, surface roughness, and object manipulation. Transduction involves mechanosensitive ion channels, such as Piezo2, that convert mechanical deformation into neural signals.

In humans, Pacinian corpuscles are densely packed in the fingertips and around joints, with sparser distributions elsewhere in the skin and in certain internal structures. Their function declines with aging or nerve damage, contributing to reduced sensitivity to vibration and deep pressure.