accessory nerve

accessory nerve (spinal accessory nerve)
the eleventh "cranial nerve (XI), which arises from two roots, cranial and spinal. Fi¬bres from the cranial root travel with the nerve for only a short distance before branching to join the vagus and then form¬ing the recurrent laiyngeal nerve, which supplies the internal laryngeal muscles. Fi¬bres from the spinal root supply the ster-nomastoid and trapezius muscles, in the neck region (front and back).