Vertebral discs are primarily made of two main components: the annulus fibrosus and the nucleus pulposus.
Here's a breakdown:
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Annulus Fibrosus: This is the tough, outer layer of the disc. It's composed of concentric layers (lamellae) of fibrocartilage, which are strong collagen fibers arranged in a crisscrossing pattern. This arrangement provides the disc with tensile strength and resistance to bending and twisting forces. Think of it as the tire of a car.
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Nucleus Pulposus: This is the soft, gel-like inner core of the disc. It's primarily composed of water, proteoglycans, and collagen. The high water content allows the nucleus pulposus to act as a shock absorber, distributing pressure evenly across the vertebral bodies. This inner core resembles a jelly-filled center, providing cushioning.
Essentially, the annulus fibrosus encapsulates and protects the nucleus pulposus, while the nucleus pulposus provides cushioning and flexibility to the spine. Together, these components allow for a wide range of motion and protect the vertebrae from impact.
