what does the intervertebral disc do
The annulus fibrosus encloses the nucleus pulposus. Although both the annulus fibrosus and nucleus pulposus are composed of water, collagen, and proteoglycans (PGs), the amount of fluid (water and PGs) is greatest in the nucleus pulposus. PG molecules are important because they attract and retain water.nnulus Fibrosus and Nucleus Pulposus. Intervertebral discs are composed of an annulus fibrosus and a nucleus pulposus. The annulus fibrosus is a strong radial tireâlike structure made up of lamellae; concentric sheets of collagen fibers connected to the vertebral end plates. The sheets are orientated at various angles.