Anythings that pass through the internal acoustic opening
Facial nerve(VII cranial nerve)
 The main trunk enters the facial canal at the fundus of internal acoustic meatus and immediately turns at a right angle posteriorly and laterally. This part is the geniculum of facial canal. It then arches posteriorly downward, passing through the stylomastoid foramen and exiting at the external surface of cranial base.
 The greater petrosal nerve from the geniculate ganglion at the geniculum of facial canal exits the canal and runs anteriorly through the groove for greater petrosal nerve of the petrous part of the temporal bone. Eventually, it passes through the foramen lacerum and exits to the external surface of cranial base.
 The chorda tympani, which divides at the lower end of the facial canal, enters the tympanic cavity (middle ear). Eventually, it exits through the petrotympanic cfissure to the external surface of cranial base.
Vestibulocochlear nerve (VIII cranial nerve)
It divids into vestibular and cochlear nerves and goes to the vestibulocochlear organ.