4.1.7 Cervical spine: intervertebral joints
Now let’s move on to look at the ligaments that connect the skull and the cervical vertebrae. Like ligaments elsewhere in the body, these structures hold the bones together, permit the bones to move in relation to one another, and set limits to their movements.
We’ll look first at the structures that permit movement between individual vertebrae, the intervertebral disks and the intervertebral joints. Then we’ll look at three ligaments that run the length of the cervical spine - the nuchal ligament, and the anterior and posterior longitudinal ligaments. Lastly we’ll look at the special ligaments around the odontoid process.
Here’s what the cervical spine looks like in the living body. Here are the spinous processes, the articular pillars, the transverse processes, and the vertebral bodies. The intervertebral joints are here. They’re synovial joints. To get a better look at them we’ll make a cut through the articular pillars along this line
As with all synovial joints, each bony surface is covered by a layer of smooth articular cartilage. The space between the cartilages is filled with lubricating synovial fluid. The fluid is contained within a fibrous joint capsule, which permits movement.
Between each vertebral body and its neighbor there’s an intervertebral disk. To see the disks we’ll make a cut in the mid-line. The disks are made of fibrocartilage that’s attached firmly to the vertebra above and below. The fibrous joints formed by the disks permit only a little movement between the regular cervical vertebrae.
The movements that can occur between these vertebrae are forward flexion, extension, and a twisting movement that’s a combination of rotation and lateral flexion. In the intervals between the occiput, the atlas, and the axis, where so much movement occurs there are no disks, only synovial joints.