Magnified view of the right cerebellopontine angle. The cerebellum has been retracted to reveal the internal aoustic canal and jugular foramen. The facial and vestibulocochlear nerves enter the internal acoustic canal with the labyrinthine artery, a branch of the anterior inferior cerebellar artery. Cranial nerves IX and X enter the jugular foramen as a complex with the ascending fibers of cranial nerve XI. The posterior inferior cerebellar artery loops near the IX-X-XI complex within the lateral medullary cistern. (Image courtesy of AL Rhoton, Jr.)