Magnified view of right cerebellopontine angle. The right cerebellum is reflected to expose the flocculus and cranial nerves emerging from the brainstem. The sigmoid sinus is also reflected at its junction with the occipital bone and posterior border of the petrous ridge of the temporal bone. The trigeminal nerve leaves the lateral pons and courses toward the apex of the petrous bone. The facial (CNVII) and vestibulocochlear (CNVIII) nerve complex leave the lateral pontomedullary junction and course to the internal auditory meatus. A loop of the anterior inferior cerebellar artery is nearby. Emerging from the anterolateral surface of the medulla and traveling to the jugular foramen are, in rostral-to-caudal sequence, the glossopharyngeal (CNIX) and vagus (CNX) nerves. Rootlets of the hypoglossal (CNXII) nerve emerge more anteriorly from the medulla and course posterior to the vertebral artery toward the hypoglossal canal. The posterior inferior cerebellar artery, the largest branch of the vertebral artery, courses around the medulla to the posterior undersurface of the cerebellum. (Image courtesy of M Nunez)