Which disc component is gelatinous, primarily water-rich, avascular, and acts as a shock absorber?

Which disc component is gelatinous, primarily water-rich, avascular, and acts as a shock absorber?

• A. Nucleus Pulposus
• B. Annulus Fibrosis
• C. Endplate
• D. Vertebral Body

Answer: (A)

The nucleus pulposus is the gelatinous, water-rich core of the intervertebral disc. Its high water content comes from proteoglycans that attract and hold water, giving it a soft, cushiony consistency. It is avascular, so nutrients reach it by diffusion from surrounding tissues. When the spine bears load, this gel-like core distributes pressure evenly, acting as a primary shock absorber and enabling smooth, flexible movement between vertebrae. The surrounding annulus fibrosus is a tough, layered ring that contains the nucleus and resists tension and torsion; it is not gelatinous. The endplates are cartilaginous interfaces that support nutrient diffusion into the disc, not shock absorbers themselves. The vertebral body is bone, providing structural support rather than a gel-like core.

The nucleus pulposus is the gelatinous, water-rich core of the intervertebral disc. Its high water content comes from proteoglycans that attract and hold water, giving it a soft, cushiony consistency. It is avascular, so nutrients reach it by diffusion from surrounding tissues. When the spine bears load, this gel-like core distributes pressure evenly, acting as a primary shock absorber and enabling smooth, flexible movement between vertebrae. The surrounding annulus fibrosus is a tough, layered ring that contains the nucleus and resists tension and torsion; it is not gelatinous. The endplates are cartilaginous interfaces that support nutrient diffusion into the disc, not shock absorbers themselves. The vertebral body is bone, providing structural support rather than a gel-like core.