Intervertebral disk – a structure that separates the vertebrae. It serves to absorb the movements of the vertebrae. Intervertebral disc consists of the so-called pulpal core special jelly mass and envelops the fibrous ring, which consists of fibers. Fibrous ring partially fixed to the adjacent vertebral bodies, and partially – to the adjacent intervertebral ligaments. Some parts of the ring are “free” and there may be some stretching of it. Excess load on the fibrous ring leads to the fact that the nucleus breaks pulpal core break fibrous ring at a greater or lesser extent. This leads to the formation of disk herniation .