BIO 135
The Vertebrae (Labeled)
Return
to:
Unlabeled
Vertebrae Page 
Axial Main Page BIO 135 Main Page
Identification hints: The three features to concentrate on when identifying the vertebrae include the size and shape of the vertebral foramen, the size and shape of the body, and shape of the spinous process. The vertebrae are listed from superior to inferior below.
- The atlas is distinctive as it is the only
vertebra without a body. Instead, the vertebral foramen extends
into the area where the body occurs in other vertebrae (the dens of the
axis fits into this area). It is also the only vertebra that lacks a spinous process.
- The axis is also unusual in that it has a large
process, the dens that extends superiorly from the body (and
fits into the anterior portion of the vertebral foramen of the atlas).
- The cervical vertebrae (which include the atlas
and axis) can be recognized by a vertebral foramen that is as large or larger than the body (consider that closer to
the head, the spinal cord carries more information but the vertebrae have
to support less weight). The spinous process of
the cervical vertebrae (except the atlas, which lacks a spinous process) has a forked or thickened tip.
Only cervical vertebrae have transverse foramen.
- The thoracic vertebrae (as well as the lumbar
vertebrae) have a body that is larger than the vertebral foramen
(supporting more weight but carrying thinner spinal cord). The vertebral foramen
is usually round and the body is distinctively heart-shaped (hint:
heart-shaped vertebrae are closest to the heart). The spinous
process is elongated, pointed, and projects downward, well below
the plane of the body.
- The lumbar vertebrae have the largest bodies,
oval in shape, while the vertebral foramen is small and somewhat
triangular. The spinous process is laterally
flattened, with a broad, rounded end that projects posteriorly
more than inferiorly.
This
page maintained by Bill
D. Snyder. Last updated October 2,
2009.