The spinal cord in humans has two ends. The bundle of nerves attach to the brainstem at the occipital bone near the base of the skull. The spinal cord then radiates away from the vertebral column, between the first and second lumbar vertebrae, roughly near the back of the navel.
The vertebral column has six additional segments below the radiation of the nerves of the spinal cord, ending with the coccyx, or tailbone. The vertebrae protect the delicate bundle of nerves and connective tissue of the spinal cord, which transmits nervous impulses from the brain to the rest of the body. The spinal cord grows larger at two areas, the cervical and lumbosacral enlargements. These areas branch out nerves that control the upper and lower limbs, respectively.