Parasagittal section through the left petrous portion of temporal and greater wing of sphenoid. The internal carotid artery can be seen passing into the carotid canal and the internal jugular vein exiting through the jugular foramen. A portion of the carotid sheath enclosing these structures has been preserved.  The lateral wall of petrous bone has been removed to visualize the facial nerve (CN VII) in the facial canal on its way to exit through the stylomastoid foramen. The Vidian nerve can be seen passing through the pterygoid canal toward the pterygopalatine fossa. It is formed by union of the greater superficial petrosal branch of the facial nerve with the deep petrosal nerve (derived from sympathetic fibers of the internal carotid nerve plexus). The mandibular nerve (CN V3) has been cut as it passes through foramen ovale to the infratemporal fossa. (Image courtesy of AL Rhoton, Jr.)