Healthy spine, side view, coloured magnetic resonance imaging (MRI) scan. The front of the body is at left. The spine runs from the head (top), where it supports the skull, to the pelvis (not seen). It is made up of blocky bones called vertebrae, which enclose and protect the spinal cord (brown, running right of the vertebrae). The spinal cord is an extension of the brainstem of the brain. The vertebrae are separated by intervertebral discs (brown areas between vertebrae), rubbery pads that cushion the spine against shocks and allow flexibility. MRI scanning uses radio waves and a powerful magnet to image body tissues.