The spinal cord consists of nerves and fibers that deliver the signals from your brain to the appropriate parts of your body. The spinal cord resides in the spinal canal, which is contained within the vertebrae. The vertebrae and the muscles around the spinal cord help protect it from damage, but they cannot protect it from all damage. Doctors describe spinal cord injuries based on the point on the spine where nerve function is interrupted. Cervical injuries are classified as C1 to C8, which is the upper part of the spine. Thoracic injuries are classified as T1 through T12 and are in the middle of the spine. Lumbar injuries are classified as L1 through L5 and are in the lower, lumbar region of the spine. If an injury is “incomplete,” some signals can still get through to the body below the injury. If an injury is “complete,” no signals can get through.