Attached to the back of each vertebral body is an arch of bone that forms a continuous hollow longitudinal space, which runs the whole length of the back. This space, called the spinal canal, is the area through which the spinal cord and nerve bundles pass. The spinal cord is bathed in cerebrospinal fluid (CSF) and surrounded by three protective layers called the meninges (dura, arachnoid, and pia mater).
At each vertebral level, a pair of spinal nerves exit through small openings called foramina (one to the left and one to the right). These nerves serve the muscles, skin and tissues of the body and thus provide sensation and movement to all parts of the body. The delicate spinal cord and nerves are further supported by strong muscles and ligaments that are attached to the vertebrae.