A glomus body (or glomus apparatus) is a component of the dermis layer of the skin, involved in body temperature regulation. The glomus body consists of an arterio-venous shunt surrounded by a capsule of connective tissue. Glomus bodies are most numerous in the fingers and toes. The role of the glomus body is to shunt blood away from the skin surface when exposed to cold temperature, thus preventing heat loss, and allowing maximum heat flow to the skin in warm weather to allow heat to dissipate. The glomus body has high sympathetic tone and blockade of sympathetic tone leads to near complete vasoconstriction.