Anterior inferior view of pontomedullary region. The left vertebral artery joins its counterpart on the right to form the basilar artery anterior to the pons. It gives off the anterior inferior cerebellar artery, several pontine branches, the superior cerebellar artery, before terminating with the posterior cerebral arteries. The trigeminal and abducens nerves can be seen leaving the pons. Sphenoid bone has been removed to expose the pituitary gland and the superior hypophyseal artery, a branch of the supraclinoid segment of the internal carotid artery. (Image courtesy of AL Rhoton, Jr.)