Discs are our shock absorbers and are present throughout the spine, separating the bones and allowing for pain-free bending and twisting of the spine. A normal disc consists of a gel-like center called nucleus pulposus and an outer shell that contains it in a place called the annulus fibrosis. Think of the Jelly filled doughnut; the center soft jelly would represent the nucleus pulposus and the outside the annulus fibrosis. Injury to the shell or the jelly-like substance may result in back pain. That is what is referred to as discogenic pain.