Internal acoustic opening

The internal acoustic opening is a large orifice found in the middle of the petrous portion of the temporal bone’s posterior surface. Positioned just under the subarcuate fossa–a slight depression above–and just above the jugular foramen. This opening gives way to a brief canal known as the internal acoustic meatus, which extends laterally. It serves as a passageway for both the facial and vestibulocochlear nerves, as well as the internal auditory or labyrinthine branch of the basilar artery.