Posterior surface of petrous part

The posterior surface of petrous part of temporal bone extends from the petrous ridge to the uneven posterior edge of the bone. This border is distinguished by a ragged edge known as the jugular notch, which marks the front margin of the jugular foramen.

The same surface forms part of the anterolateral floor of the posterior cranial fossa within the skull and includes several noteworthy anatomical features. Right below the petrous ridge, although somewhat difficult to see, is an aperture for the vestibular canaliculus—a channel that leads from the vestibule of the bony labyrinth to the posterior surface of petrous part, opening into the posterior cranial fossa. Lower down is the entrance to the internal acoustic meatus, which carries both the labyrinthine artery and two cranial nerves: the facial and the vestibulocochlear nerves. Situated between the vestibular canaliculus and the internal acoustic meatus is a shallow depressed area of bone known as the subarcuate fossa.