II. Vertebral Column
The vertebral column is tremendously important- it is the central pillar of the body. Try to understand the relationship between the vertebral column's structural and functional characteristics. Dr. Rizzolo covers this material in a concise manner in his lecture notes. Concentrate on the general features of a typical vertebrae and the distinguishing features of vertebrae in different regions. Be sure to examine the actual vertebrae in your bone box. Use the lecture notes and the diagrams on the following pages to become familiar with the important terms below.
-superior vertebral notch
-inferior vertebral notch
The following diagrams depict a typical vertebrae. Learn the indicated features. Compare these diagrams with the actual vertebrae in your bone box.
It is important to know distinguishing characteristics of the different regions of the vertebral column. These characteristics are easy to learn as that the structural features correlate with the functional requirements of each region.
Atlas and Axis- The first two cervical vertebrae are atypical.
-No body and no spinous process
-Superior articular facet- forms a synovial joint with the skull- allows up and down motion (nodding yes)
-Articulates inferiorly with the dens of the axis
-Rotation about the dens allows rotation of head
-characterized by the presence of the dens (odontoid process)
-dens- represents the body of atlas that has fused with the axis
- projects superiorly from the body of the axis and articulates with the anterior arch of the atlas
- forms pivot around which the atlas rotates
Typical Cervical Vertebrae
-main distinguishing characteristic is the transverse foramina in the transverse process
-the transverse foramina transmit the vertebral arteries
-spinous process are bifid
-C7 has some unique features- its long spinous process is not bifid - called vertebrae prominens due to long spinous process - transverse foramina are small and do not transmit vertebral arteries
Typical Thoracic Vertebrae
-anchor the rib cage
-articular facets for the ribs are on the body and transverse processes
-spinous processes are long and inclined downward- protect the spinal cord
Typical Lumbar Vertebrae
-most massive vertebrae- anchor the large muscles that control movement
-spinous processes project directly posteriorly- exposes intervertebral space and allows insertion of needle to access spinal fluid
-does not have rib facets or foramina in the transverse processes
Typical Sacral Vertebrae
-sacral vertebrae are fused- form the sacrum
-transfer weight of torso to hips and legs
-sacral hiatus- formed by the failure of the laminae of the lower vertebrae to meet in the midline