The fibrocartilage cushions between the vertebrae in the column are named for their positions along the vertebral bodies, and are called the intervertebral disks. They have a thick outer ring of cartilage called the Annulus Fibrosus as well as a much softer center called the Nucleus Pulposus. This is not where the nerve tissue passes through, as some would suggest. Its purpose is to allow the joints to flex to some degree and to provide cushion for any axial compression that may occur. The only exception to the disk arrangement is that the first cervical vertebra does not have a body to articulate with the vertebra below it.