Glomus

, pl. glomeraAvoid the incorrect plural glomi for this word. (1) [TA], A small, globular body. (2) A highly organized arteriolovenular anastomosis forming a tiny nodular focus in the nailbed, in the pads of the fingers and toes, ears, hands, feet, and in many parts and organs of the body. The afferent arteriole enters the connective tissue capsule of the glomus, becomes devoid of an internal elastic membrane, and develops a relatively thick epithelioid muscular wall and small lumen; the anastomosis may be branched and convoluted, richly innervated with sympathetic and myelinated nerves, and connected with a short, thin-walled vein that drains into a periglomic vein and then into one of the veins of the skin. The glomus functions as a shunt- or bypass-regulating mechanism in blood flow, temperature, and conservation of heat in the part as well as in indirect control of the blood pressure and other functions of the circulatory system. SYN: glandulae glomiformes (1), glomiform glands, glomus body. SYN: glome. [L. glomus, a ball]