Right anterolateral view jugular foramen region. Bone of the right lower clivus and adjacent parts of the occipital bone were removed to expose the rostral medulla and pontomedullary junction. The right vertebral artery is shown joining the left artery to form the basilar artery. A portion of the posterior inferior cerebellar artery is in view on the right side and is commonly a branch of the ipsilateral vertebral artery. Along the rostral lateral medulla emerge in sequence (rostral to caudal) the glossopharyngeal (CNIX), vagus (CNX), and spinal accessory (CNXI) nerves. These nerves converge on the jugular foramen. The hypoglossal (CNXII) nerve exits the sulcus between the medullary pyramid and olive and passes toward and through the hypoglossal canal. (Image courtesy of AL Rhoton, Jr.)