Coracoid

Coracoid

A coracoid is a paired bone which is part of the shoulder assembly in all vertebrates except therian mammals (therians = marsupials and placentals). In therian mammals (including humans), a coracoid process is present as part of the scapula, but this is not homologous with the coracoid bone of most other animals.[1]

In other tetrapods it joins the scapula to the front end of the sternum and has a notch on the dorsal surface which, along with a similar notch on the ventral surface of the scapula, forms the socket in which the proximal end of the humerus (upper arm bone) is located. The acrocoracoid process is an expansion adjacent to this contact surface, to which the shoulderward end of the biceps brachii muscle attaches in these animals. In birds (and generally theropods and related animals), the entire unit is rigid and called scapulocoracoid. This plays a major role in bird flight.

In fish it provides the base for the pectoral fin.[2]

Monotremes, as well as the extinct therapsids, possess both the coracoid bone of reptiles (here referred to as the procoracoid, or anterior coracoid), and the coracoid process of other mammals, with the latter being present as a separate bone.[1]

See also

Notes

  1. ^ a b Romer, Alfred Sherwood; Parsons, Thomas S. (1977). The Vertebrate Body. Philadelphia, PA: Holt-Saunders International. pp. 186–187. ISBN 0-03-910284-X. 
  2. ^ FishBase 2006

References


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Look at other dictionaries:

  • coracoid — CORACOÍD, Ă, coracoizi, de, adj. (Şi substantivat, f.) (Formaţie anatomică) care se aseamănă cu un cioc de corb. ♢ Apofiză coracoidă = apofiză a omoplatului. – Din fr. coracoïde. Trimis de romac, 13.09.2007. Sursa: DEX 98  coracoíd adj. m. (sil …   Dicționar Român

  • Coracoid — Cor a*coid, n. The coracoid bone or process. [1913 Webster] …   The Collaborative International Dictionary of English

  • Coracoid — Cor a*coid, a. [Gr. ?; ko rax crow + e i^dos form.] 1. Shaped like a crow s beak. [1913 Webster] 2. (Anat.) Pertaining to a bone of the shoulder girdle in most birds, reptiles, and amphibians, which is reduced to a process of the scapula in most… …   The Collaborative International Dictionary of English

  • Coracoid — Coracoid, Rabenschnabelbein ⇒ Schultergürtel …   Deutsch wörterbuch der biologie

  • coracoid — [kôr′ə koid΄] adj. [ModL coracoides < Gr korakoeidēs, like a raven < korax,RAVEN1 + eidos, OID] designating or of a rudimentary bony process on the shoulder blade in mammals, or a bone in monotremes and certain fossil reptiles that extends… …   English World dictionary

  • Coracoid — Skelett eines Afrikanischen Straußes von vorn. 1 Brustbein, 2 Coracoid, 3 Schlüsselbein, 4 Schulterblatt (5 Oberarmknochen, 6 Rippen, 7 Oberschenkelknochen, 8 Schienbein, 9 Wadenbein) Das Coracoid oder Os coracoideum (Raben(schnabel)bein, zu gr.… …   Deutsch Wikipedia

  • coracoid — Shaped like a crow s beak; denoting a process of the scapula. [G. korakodes, like a crow s beak, fr. korax, raven, + eidos, appearance] * * * cor·a·coid kȯr ə .kȯid, kär adj of, relating to, or being a process of the scapula in most mammals or… …   Medical dictionary

  • coracoid — adjective Etymology: New Latin coracoides, from Greek korakoeidēs, literally, like a raven, from korak , korax raven more at raven Date: 1741 of, relating to, or being a process of the scapula in most mammals or a well developed cartilage bone of …   New Collegiate Dictionary

  • coracoid — /kawr euh koyd , kor /, Anat., Zool. adj. 1. pertaining to the bone that in reptiles, birds, and monotremes articulates with the scapula and the sternum and that in humans and other higher mammals is a reduced bony process of the scapula having… …   Universalium

  • coracoid — 1. noun a) Part of the scapula that projects towards the sternum in mammals; the coracoid process b) A small bone linking the scapula and sternum in birds, reptiles and some other vertebrates 2. adjective …   Wiktionary

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