Final answer:
A herniated disc is an injury to the vertebral column that happens when the soft nucleus pulposus protrudes through a weakened anulus fibrosus, causing nerve compression and associated pain and muscle weakness. Commonly affected areas are the lower lumbar region, and the condition can lead to sciatica if not properly treated.
Step-by-step explanation:
A herniated disc occurs when there is a weakening of the anulus fibrosus, the tough outer layer of an intervertebral disc, which causes the soft, gel-like nucleus pulposus to protrude or herniate. This can lead to compression of a spinal nerve, resulting in pain and muscle weakness in the regions of the body that are supplied by the affected nerve. The intervertebral discs are crucial for allowing flexibility and movement of the vertebral column while also acting as shock absorbers between the vertebrae.
The spinal column, essential for supporting the head and upper body, can be subjected to increased stress due to factors such as weight, curvature, and movement. Conditions like being overweight or engaging in activities involving heavy lifting can exacerbate the risk of anulus fibrosus weakening and disc herniation. Herniated discs are most commonly found in the lower lumbar region, particularly the L4/L5 or L5/S1 intervertebral discs, which can lead to sciatica—pain that radiates from the lower back down the leg. Treatment options often include rest, physical therapy, and in some cases, surgical intervention.