Which intervertebral disk component forms the outermost ring with concentric laminae and contributes to disk stability?

• A. Nucleus pulposus
• B. Annulus fibrosus
• C. Ligamentum flavum
• D. Dorsal longitudinal ligament

Answer: (B)

The annulus fibrosus is the outermost ring of the intervertebral disc, formed by multiple concentric lamellae of collagen fibers arranged in alternating directions. This layered, fibrous structure provides tensile strength and helps contain the nucleus pulposus at the center, resisting torsion, bending, and shear forces to stabilize the disc. The nucleus pulposus sits centrally as a gelatinous core, while ligaments like the ligamentum flavum and the dorsal longitudinal ligament are stabilizers of the spine but do not form the disc’s outer lamellar ring.