Spine and Nerve Anatomy
Details of the Lumbar Disk
The vertebral disk has a complex design with two major components. There is an outer retaining ring called the annulus fibrosus which is made up of alternating layers of strong sheets of ligaments . This part of the disk helps hold the vertebrae together, limits their range of movement, and contains the inner, elastic core of the disk. The inner part is the nucleus pulposus. This is a spongy, elastic material that helps provide a “shock absorber” function between each pair of vertebrae.