Right lateral view of the middle fossa which has been drilled to expose the internal auditory canal, cochlea, the superior semicircular canal, and tympanic cavity. Note the landmark trigeminal nerve and its course from the pons to the trigeminal depression where it expands as the trigeminal ganglion. Its three divisions (ophthalmic, maxillary, mandibular) are seen through meningeal dura as is the middle meningeal artery emerging through foramen spinosum. The facial and superior vestibular nerves are in view within the internal auditory canal, the facial being anterior to the superior vestibular. The facial nerve ends at its geniculate ganglion from which arises the greater superficial petrosal and main trunks. Portions of the facial nerve (labyrinthine segment and tympanic segment) are in view. (Image courtesy of AL Rhoton, Jr.)