Corpuscule

Corpuscule is a term used in biology and medicine to denote a small body or particle. The word comes from Latin corpusculum, meaning “a small body.” In modern usage it often refers to well-defined structures within tissues, particularly sensory receptors formed by nerve endings enclosed in connective tissue.

The most familiar corpuscles are mechanoreceptors in the skin. Pacinian corpuscles are large, onion-like, lamellated structures located deep in the dermis and subcutaneous tissue; they detect deep pressure and high-frequency vibration. Meissner’s corpuscles, or tactile corpuscles, reside in the dermal papillae of glabrous (hairless) skin such as fingertips and lips, and respond to light touch and low-frequency vibrations. Ruffini endings are spindle-shaped receptors in the dermis and subcutaneous tissue that respond to skin stretch and sustained pressure. Krause end bulbs are cold receptors found in mucous membranes and some skin regions.

Historically, the term corpuscle has also been used more generally to denote small particles or cells, including older references to “blood corpuscles” (red and white blood cells). In the history of science, corpuscle was used to describe the particle aspect of light or matter in early theories, a usage largely superseded by modern terminology.

In sum, corpuscule (singular) most often designates a small, specialized body within tissue, especially encapsulated sensory receptors, while the broader historical usage spans other small bodies and particle concepts.