Anatomy of the Spine The anterior portion of the spine consists of cylindrical vertebral bodies separated by intervertebral disks and held together by the anterior and posterior longitudinal ligaments. The intervertebral disks are composed of a central gelatinous nucleus pulposus surrounded by a tough cartilaginous ring, the annulus fibrosis; disks are responsible for 25% of spinal column length (Figs. 16-1 and 16-2). The disks are largest in the cervical and lumbar regions where movements of the spine are greatest. .
