Opening in the suture between the petrous portion and occipital bone; transmits the lateral sinus and ninth, tenth, and eleventh cranial nerves
Mastoid air cells
Mucosa-lined, air-filled spaces within the mastoid process
Squamous
Thin, flaring upper part of bone
Mastoid portion
Rough-surfaced lower part of the bone posterior to the external acoustic meatus
Stylomastoid foramen
Opening between the styloid and mastoid processes where the facial nerve emerges from the cranial cavity
External acoustic meatus (or canal)
Tube extending into the temporal bone from the external ear opening to the tympanic membrane
Carotid canal (or foramen)
Channel in the petrous portion; best seen from the undersurface of the skull; transmits the internal carotid artery
Internal acoustic meatus
Fairly large opening on the posterior surface of the petrous portion of the bone; transmits the eighth cranial nerve to the inner ear and the seventh cranial nerve on its way to the facial structures
Mastoid process
Protuberance just behind the ear
Jugular fossa
depression of the undersurface of the petrous portion; dilated beginning of the internal jugular vein lodged here
