Vertebrae

3 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Vertebra \Ver"te*bra\ (v[~e]r"t[-e]*br[.a]), n.; pl.
     {Vertebrae}. [L. vertebra, fr. vertere to turn, change. See
     {Verse}.]
     [1913 Webster]
     1. (Anat.) One of the serial segments of the spinal column.
        [1913 Webster]


  
     Note: In many fishes the vertebrae are simple cartilaginous
           disks or short cylinders, but in the higher vertebrates
           they are composed of many parts, and the vertebrae in
           different portions of the same column vary very
           greatly. A well-developed vertebra usually consists of
           a more or less cylindrical and solid body, or centrum,
           which is surmounted dorsally by an arch, leaving an
           opening which forms a part of the canal containing the
           spinal cord. From this dorsal, or neural, arch spring
           various processes, or apophyses, which have received
           special names: a dorsal, or neural, spine, spinous
           process, or neurapophysis, on the middle of the arch;
           two anterior and two posterior articular processes, or
           zygapophyses; and one or two transverse processes on
           each side. In those vertebrae which bear well-developed
           ribs, a tubercle near the end of the rib articulates at
           a tubercular facet on the transverse process
           (diapophysis), while the end, or head, of the rib
           articulates at a more ventral capitular facet which is
           sometimes developed into a second, or ventral,
           transverse process (parapophysis). In vertebrates with
           well-developed hind limbs, the spinal column is divided
           into five regions in each of which the vertebrae are
           specially designated: those vertebrae in front of, or
           anterior to, the first vertebra which bears ribs
           connected with the sternum are cervical; all those
           which bear ribs and are back of the cervicals are
           dorsal; the one or more directly supporting the pelvis
           are sacral and form the sacrum; those between the
           sacral and dorsal are lumbar; and all those back of the
           sacral are caudal, or coccygeal. In man there are seven
           cervical vertebrae, twelve dorsal, five lumbar, five
           sacral, and usually four, but sometimes five and rarely
           three, coccygeal.
           [1913 Webster]
  
     2. (Zool.) One of the central ossicles in each joint of the
        arms of an ophiuran.
        [1913 Webster]
        [1913 Webster]

From WordNet (r) 2.0 [wn]:

  vertebra
       n : one of the bony segments of the spinal column
       [also: {vertebrae} (pl)]

From WordNet (r) 2.0 [wn]:

  vertebrae
       See {vertebra}