Final answer:
The deterioration of the nucleus pulposus leads to intervertebral disc herniation, causing conditions such as sciatica and pain in various regions of the body depending on the compromised spinal nerve.
Step-by-step explanation:
Deterioration of the nucleus pulposus results in herniation of the intervertebral disc, commonly referred to as a herniated, ruptured, or slipped disc. This deterioration can lead to compression of a spinal nerve, which may cause pain and/or muscle weakness in the body regions that the affected nerve supplies.
The nucleus pulposus, found within the center of each intervertebral disc, is a gel-like substance that serves to resist compression, allowing the disc to absorb pressure and distribute weight evenly across the spine. The anulus fibrosus is the tough, fibrous outer layer that encases the nucleus pulposus. With age or injury, water content in the nucleus pulposus can decrease, resulting in a thinner disc, less flexibility, and compromised structural integrity. As the anulus fibrosus weakens or gets damaged, it can lead to the nucleus pulposus protruding outwards, especially when pressure is placed on the spine by actions such as bending forward.
The most frequent sites of disc herniation are the L4/L5 and L5/S1 levels, which can result in symptoms like sciatica. Injuries to the C5/C6 or C6/C7 intervertebral discs can bring about pain in areas like the neck, shoulder, and upper limbs.