Final answer:
The annulus fibrosus is the tough, fibrous outer layer of an intervertebral disc that provides stability and strength. It is firmly anchored to the adjacent vertebral bodies. Inside the annulus fibrosus is the nucleus pulposus, which allows for shock absorption and flexibility.
Step-by-step explanation:
The anulus fibrosus is the tough, fibrous outer layer of an intervertebral disc. It forms a circle and is strongly anchored to the adjacent vertebral bodies. Inside the anulus fibrosus is the nucleus pulposus, which is a softer, gel-like material. The anulus fibrosus provides stability and strength to the intervertebral disc, while the nucleus pulposus allows for shock absorption and flexibility.