The posterior cranial fossa is defined superiorly by the tentorium . Identify the attachment of the tentorium along the superior ridge of the petrous part of the temporal bone. Find the internal auditory meatus a little posterior to the apex of the petrous part of the temporal bone. Facial and vestibulocochlear nerves. Vestibulocochlear supplies the ear, facial passes throught the facial canal in the petrous part of the temporal bone and exits the skull through the stylomastoid foramen.
Facial nerve innervates the muscles of facial expression.
Anterior to the petrous part of the temporal bone lies the opening of the carotid canal transmitting the internal carotid artery. Posterior to the carotid canal lies the jugular foramen. Venous blood from the brain, collected in the venous sinuses of the skull, passes through the foramen to flow into the internal jugular vein. Observe the markings on the internal aspect of the skull of the transverse and sigmoid venous sinus. Superior sagittal sinus.