Degenerative Disc Disease
Anatomy of the Spine video 3D animation demonstrating the anatomy of the spine, including bony landmarks of the vertebrae, intervertebral discs, and ligaments. Degenerative Disc Disease picture album Several pictures illustrating the anatomy, pathology, and treatment option for degenerative disc disease. Radiculopathy video 3D animation depicting the anatomy and pathology of lumbar and cervical radiculopathy.
The spine is made up of several bones known as vertebrae.  The spine helps provide flexible structure to the neck and back.  It also serves to protect the spinal cord, which carries sensory and motor signals between the brain and the rest of the body. The 7 vertebrae in the neck are known collectively as the cervical spine.  The 12 vertebrae in the thorax are known as the thoracic spine.  The 5 vertebrae in the low back are known as the lumbar spine.  The sacrum is formed by 5 fused vertebrae below the lumbar spine.  And the coccyx, or tailbone, is formed by 4 fused vertebrae below the sacrum. Each vertebra consists of a vertebral body, a vertebral arch, and several processes that provide points of attachment for ligaments or articulate with other vertebrae. The spinal cord passes through the vertebral foramen, meaning the space created by the vertebral arch.  The arch consists of the pedicle, which attaches the main body of the vertebra to the transverse processes, and the lamina, which attaches the transverse processes to the spinous process. Jutting out above and below the transverse processes are the articular processes.  Each articular process has a facet that articulates with the facets of the vertebrae above and below it.  Between the vertebral bodies are shock absorbers known as intervertebral discs.  The discs are more flexible than the bony vertebrae, and allow for a small amount of movement between each vertebra.  The cumulative movement between several vertebrae allows for a great deal of flexibility in the neck and back. Each disc is composed of a gel-like core, the nucleus pulposus, surrounded by a ring of fibrocartilage, the anulus fibrosus.  The semifluid nature of the nucleus pulposus allows for compression and stretching which absorbs shock between the vertebrae and allows for flexibility. Ligaments (strong, fibrous bands of soft tissue) hold the different parts of the vertebrae together, contributing to the stability of the spine.  The anterior and posterior longitudinal ligaments run along the anterior and posterior aspects of the vertebral bodies.  The laminae are connected by the ligamenta flava.  The facet joints are surrounded by small, ligamentous capsules.  Each transverse process is connected by an intertransverse ligament.  Each spinous process is connected by a thin interspinous ligament and a stronger supraspinous ligament. The notches above and below the pedicles form spaces for the spinal nerves to leave the spinal cord and branch out to the body.  These spaces are known as the intervertebral foramen.