Left lateral view of tympanic and mastoid regions following selective removal of temporal bone. The mandible has been removed to reveal the posterior edge of the infratemporal fossa and lateral deep neck structures. Note the entrance and exit, respectively, of the internal carotid artery and internal jugular vein from their respective bony openings and a complement of carotid sheath enclosing them. The mastoid segment of the facial nerve is also visible and it emerges out of the stylomastoid foramen. Here, the stylomastoid artery, a branch of the posterior auricular artery, can be seen ascending in company with the facial nerve to enter the stylomastoid foramen. The chorda tympani is shown arching across the tympanic cavity from posterior to anterior medial to the handle of the malleus. It emerges through the petrotympanic fissure to enter the infratemporal fossa. (Image courtesy of AL Rhoton, Jr.)