1. [NA] A small head or rounded articular extremity of a bone. SYN: capitellum (1). SEE ALSO: caput. 2. The bloodsucking, probing, sensing, and holdfast mouthparts of a tick, including the basal supporting structure; relative size and shape of mouthparts forming the c. are characteristic for the genera of hard ticks. [L. dim. of caput, head]
- c. of humerus [TA] the small rounded eminence on the lateral half of the distal end of the humerus for articulation with the radius. SYN: c. humeri [TA], capitellum (2), little head of humerus.
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a) the knob at the end of a bone or cartilage
b) the beak of a tick composed of the mouthparts and palpi
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n.
the small rounded end of a bone that articulates with another bone. For example, the capitulum humeri (or capitellum) is the round prominence at the elbow end of the humerus that articulates with the radius.
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ca·pit·u·lum (kə-pitґu-ləm) pl. capitґula [L. dim. of caput] 1. a little head, or a small eminence on a bone by which it articulates with another bone. 2. a bulbous, knoblike, or enlarged terminal protuberance of a body or part, such as: (a) the movable head zone (gnathosoma) bearing the mouth parts of a tick or mite; (b) the end of an insect's antennae; or (c) the anterior end of the axostyle of certain zooflagellates, containing the nucleus of the organism.Medical dictionary. 2011.