Right anterior view of the pons and overlying basilar artery following removal of the clivus and portion of the petrous part of the temporal bone. The abducens nerve can be seen piercing dura mater on the clivus before entering the parasellar area. The petrous segment of the internal carotid artery is visible along with its carotid sympathetic plexus. The glossopharyngeal, vagus , spinal accessory, and hypoglossal nerves can be seen converging on their foramina of exit. (Image courtesy of AL Rhoton, Jr.)