Right lateral view of the middle fossa following removal of the petrous apex. For orientation, the bottom border of the image is superior; the top border is inferior. The trigeminal nerve occupies the middle of the field and from its ganglionic expansion, gives rise to its ophthalmic, maxillary, and mandibular nerve branches. The oculomotor and trochlear nerves converge on the ophthalmic nerve at the superior orbital fissure. Note the abducens nerve and its course beneath the petrosphenoidal ligament to enter the cavernous sinus coursing lateral to the internal carotid artery to the superior orbital fissure. Note also the inferior petrosal sinus coursing on the lateral edge of the clivus (petroclival junction) draining the cavernous sinus to the internal jugular vein. (Image courtesy of AL Rhoton, Jr.)