Intervertebral disc. Model of one of the intervertebral discs (at lower centre) that cushion the bones of the human spine. The spinal cord (at upper centre) is orange. These discs fit between the vertebrae (one seen behind disc) of the spine, supporting the spinal column while still allowing flexibility. The outer part of each oval disc consists of a dense, fibrous connective tissue called fibrocartilage, which can withstand considerable pressure. In the disc's core is a jelly-like fluid called the nucleus pulposus (pink), which acts as a hydraulic shock-absorber. To view a model of a prolapsed disc, see image M330/724.