Ventral view of brainstem and cerebellum and emergence of cranial nerves. The brain stem consists of the midbrain, pons, and medulla. The oculomotor nerve (CN III) exits at the midbrain and pontine junction while the trigeminal nerve (CN V) exits at the lateral pons. The trochlear nerve (CN IV) is not seen in this image as it exits from the dorsal midbrain (the only cranial nerve to do so). Abducens nerve (CN VI) exits medially at the pontomedullary junction while facial (CN VII) and vestibulocochlear (CN VIII) nerves exit at this junction more laterally. Glossopharyngeal (CN IX) and vagus (CN X) nerves exit the medulla lateral to the olives. The spinal  accessory nerve (CN XI) arises from ventral horn cells of the upper five cervical spinal segments and ascends through the foramen magnum to exit through the jugular foramen with glossopharyngeal and vagus nerves. The hypoglossal nerve exits the medulla between the pyramids and olives to pass through the hypoglossal canals. (Image courtesy of AL Rhoton, Jr.)