Section 422: The non-sensory portions of the superior (ssc), posterior (psc) and lateral (lsc) semicircular canals are visible. The endolymphatic duct (ed) is approaching the vestibule. There is a dehiscence in the bony canal over the tympanic segment (VIId) of the facial nerve. The body of the incus (i) is visible in the epitympanic recess. The tympanic membrane has been artifactually ruptured.