Final answer:
Intervertebral discs are crucial for spinal flexibility and shock absorption. Degradation of these discs, particularly the anulus fibrosus, can lead to disc herniation, compressing spinal nerves and causing pain and weakness in corresponding regions of the body. Increased shear forces from altered spinal curvature, as seen in overweight individuals and pregnant women, can exacerbate these issues.
Step-by-step explanation:
Degeneration of Intervertebral Discs and Loading Effects
The intervertebral discs are composed of fibrous cartilage and play a crucial role in the spinal column's function, providing support and flexibility. These discs absorb shocks from daily activities such as walking and running and allow for some movement of the spine. The disc itself can be broken down into two components: the nucleus pulposus, which is gel-like and allows the disc to change shape during spinal movements, and the surrounding anulus fibrosus.
As we age or sustain injuries, the nucleus pulposus can harden and lose elasticity, leading to a decrease in its shock-absorbing abilities. Moreover, the anulus fibrosus can weaken, which might result in a herniated disc, commonly referred to as a 'ruptured' or 'slipped' disc. This can cause the nucleus pulposus to protrude and compress a spinal nerve, leading to pain and muscle weakness in the body regions supplied by the affected nerve, such as in cases of sciatica or neck and limb pain after a traumatic injury.
Pregnant women and individuals who are overweight might increase the curvature of their spine to maintain balance, which increases the shear forces acting on their vertebrae and discs. This can increase the risk of back injury and disc herniation, particularly in the lumbosacral region. Overall, disc degeneration affects the spine's ability to handle load-bearing activities, resulting in various health complications.