"....A disc is a round, cushioned structure that is wedged in between two vertebrae. It acts as a shock absorber to alleviate the pressure on the vertebrae if there is an external force exerting pressure on the spine. The best way to describe the disc is by picturing a jelly doughnut. The center, or the nucleus, is filled with a gelatinous material which acts as the cushion. The tougher fibrous outer layer, the annulus, is thicker and can withstand the forces placed upon it......"
