Because the spine can go in many directions, strong forces act upon it during movement and activity. The intervertebral disk absorbes the shock from spinal movement. It protects both the vertebrae and spinal cord from trauma.
How does the disk do this?
On the outside strong fibers are woven together to form an area called the annulus fibrosis. The annulous fibrosis contains and protects a softer, more squishy substance in the middle called the nucleus pulposus. The nucleus pulposis is responsible for yielding and giving during spinal movement. In this way, the disk acts as a shock absorber.
