vertebra 音标拼音: [v'ɚtəbrə]
n . 脊椎骨,椎骨
脊椎骨,椎骨
vertebra n 1 :
one of the bony segments of the spinal column 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 ]
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