Left lateral view of tympanic and mastoid regions following selective removal of temporal bone. The mandible has been removed to reveal 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 into which the stylomastoid artery can be seen entering. The chorda tympani is shown arching across the tympanic cavity from posterior to anterior and it emerges through the petrotympanic fissure to enter the infratemporal fossa. The sigmoid sinus communicates with the jugular bulb before the latter continues as the internal jugular vein. (Image courtesy of AL Rhoton, Jr.)