The intervertebral discs sit between the vertebrae. Their function is to provide movement to the spine as well as absorb shock. Discs are made up of outer annulus fibers that are a sort of elasto-cartilage, and an interior jelly like substance called nucleous pulposa. Sometimes the disc can get damaged. It can compress and flatten increasing its diameter, or it can crush and rupture causing the interior to leak out, sometimes onto a nerve.
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