occipital


occipital
occipitally, adv.
/ok sip"i tl/, Anat.
adj.
1. of, pertaining to, or situated near the occiput or the occipital bone.
n.
2. any of several parts of the occiput, esp. the occipital bone.
[1535-45; < ML occipitalis, equiv. to L occipit- (s. of occiput) OCCIPUT + -alis -AL1]

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bone
      bone forming the back and back part of the base of the cranium, the part of the skull that encloses the brain. It has a large oval opening, the foramen magnum, through which the medulla oblongata passes, linking the spinal cord and brain. The occipital adjoins five of the other seven bones forming the cranium: at the back of the head, the two parietal bones; at the side, the temporal bones; and in front, the sphenoid bone, which also forms part of the base of the cranium. The occipital is concave internally to hold the back of the brain and is marked externally by nuchal (neck) lines where the neck musculature attaches. The occipital forms both in membrane and in cartilage; these parts fuse in early childhood. The seam, or suture, between the occipital and the sphenoid closes between ages 18 and 25, that with the parietals between ages 26 and 40.

      In four-footed animals the head hangs from the end of the vertebral column, and the foramen magnum is placed posteriorly. The nuchal musculature is strongly developed to support the head, and the occipital markings are heavy.

      In apes (ape), with the assumption of semierect posture, the foramen has moved partially downward and forward. The nuchal muscles are powerful and attached high up on the occipital near the suture with the parietals, where a crest (lambdoidal crest) sometimes forms. In human evolution, the foramen magnum has continued to move forward as an aspect of adaptation to walking on two legs, until the head is now balanced vertically on top of the vertebral column. Concurrently, the line of attachment of the nuchal musculature has moved downward from the lambdoidal suture to a point low on the back of the head. In such precursors of man as Australopithecus and Homo erectus, the nuchal markings, often heavy enough to form a protuberance, or torus, were intermediate in position between those in apes and those in modern man.

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Universalium. 2010.

Look at other dictionaries:

  • occipital — occipital, ale, aux [ ɔksipital, o ] adj. • av. 1478; lat. médiév. occipitalis ♦ Anat. Qui appartient à l occiput. Os occipital, et n. m. l occipital : os qui forme la partie inférieure et postérieure du crâne. Trou occipital : large ouverture de …   Encyclopédie Universelle

  • occipital — OCCIPITÁL, Ă, occipitali, e, s.n., adj. 1. s.n. Os nepereche lat, care formează partea de dinapoi şi de jos a cutiei craniene. 2. adj. Care aparţine occipitalului (1), care se referă la occipital. ♢ Lobul occipital = lobul posterior al creierului …   Dicționar Român

  • occipital — adj. anat. Relativo al hueso o a la región occipital. Medical Dictionary. 2011. occipital relativo al occipucio. Porción posterior …   Diccionario médico

  • Occipital — Oc*cip i*tal, a. [Cf. F. occipital.] (Anat.) Of or pertaining to the occiput, or back part of the head, or to the occipital bone. [1913 Webster] {Occipital bone} (Anat.), the bone which forms the posterior segment of the skull and surrounds the… …   The Collaborative International Dictionary of English

  • occipital — occipital, ale (o ksi pi tal, ta l ) adj. Qui appartient à l occiput. Muscles occipitaux.    L os occipital, ou, substantivement, l occipital, os symétrique formant la paroi postérieure inférieure du crâne. HISTORIQUE    XVIe s. •   L os… …   Dictionnaire de la Langue Française d'Émile Littré

  • occipital — adjetivo 1. Área: anatomía Del occipucio: región occipital. adjetivo,sustantivo masculino 1. Área: anatomía [Hueso] …   Diccionario Salamanca de la Lengua Española

  • occipital — (Del lat. occĭput, ĭtis, nuca). 1. adj. Perteneciente o relativo al occipucio. 2. m. Anat. hueso occipital. ☛ V. ángulo occipital …   Diccionario de la lengua española

  • occipital — [äk sip′it l] adj. [ML occipitalis] of the occiput or the occipital bone n. OCCIPITAL BONE occipitally adv …   English World dictionary

  • Occipital — Oc*cip i*tal, n. (Anat.) The occipital bone. [1913 Webster] …   The Collaborative International Dictionary of English

  • occipital — (adj.) 1540s, from M.Fr. occipital, from M.L. occipitalis, from L. occiput (gen. occipitis) back of the skull, from ob against, behind (see OB (Cf. ob )) + caput head (see HEAD (Cf. head) (n.)) …   Etymology dictionary

  • occipital — adj. 2 g. 1. Do occipício ou a ele relativo. • s. m. 2. Occipício. 3.  [Anatomia] osso occipital: osso posterior do crânio …   Dicionário da Língua Portuguesa


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