Each spinal nerve exits the vertebral column through a small hole, or foramen, on the side of the corresponding vertebrae, CNS-Visual Perspectives explains. The cervical nerves in the upper part of the spine exit above the vertebrae, while the nerves below the seventh cervical vertebrae exit below.
Thirty-one pairs of spinal nerves exit through the foramina on the right and left sides of the vertebrae, explains CNS-Visual Perspectives. Scientists label these nerves according to their locations in the spine. There are four major regions: In descending order, they are the cervical region, which begins at the base of the skull; the thoracic region, which starts in the upper back; and the lumbar and sacral regions of the middle and lower back. The eight pairs of cervical nerves control the movement and sensation in the arms, neck and upper trunk. The 12 pairs of nerves in the thoracic region control the trunk and abdomen, and the 10 nerve pairs in the lumbar-sacral region control the legs, bladder, bowels and sexual organs. The remaining nerve pair is in the coccygeal region at the base of the spine.
The spinal cord in an adult ends at the level of the first- and second-lumbar vertebrae, states Inner Body.com. As a result, the cervical and thoracic nerves exit the spine almost horizontally, while nerves in the lower spine exit at an angle below the spinal cord.