In the cochlear nerve

MCQs in OTOLARYNGOLOGY 13 In the labyrinthA The orifice of the vestibular aqueduct is located in the anterior part of the medial wall of the bony vestibule.8 The most superior part of the superior semicircular canal is located beneath the arcuate eminence.C In the anatomical position the plane of the lateral semicircular canals is at an angle of 30 degrees to horizontal, tilting down posteriorly.D The osseous labyrinth contains endolymph and the membranous labyrinth perilymph.E The scala media is also known as the cochlear duct. In the inner earA The scala tympani, containing endolymph, communicates with the subarachnoid space via the cochlear aqueduct.8 Cortilymph is similar to perilymph.C There are 3-4 rows of outer hair cells which are arranged in rows in a pattern of a W. D The inner hair cells are columnar in shape compared to the outer hair cells which are bulbous.E The stria vascularis is located on the outer aspect of the cochlear duct.15 In the cochlear nerve A The type I fibres are probably efferent and type II probably afferent.8 The dorsal root ganglion is represented by the spiral ganglion and the nerve by the central processes.C The first synapse is at the dorsal and ventral cochlear nuclei after which the majority of fibres ascend in the contralateral lateral lemniscus.D The primary auditory centres are located in the trapezoid body.E The olivocochlear fibres are type II fibres, originate from both olivary nuclei and terminate at the base of the cochlea.16 In the vestibular labyrinth A The three semicircular ducts open into the utricle by six separate openings.8 The utriculo-endolymphatic valve consists of flaps of mucosa permitting inflow and not outflow of endolymph.C The macula of the utricle lies in the horizontal plane and that of the saccule in a vertical plane.D The hair cells of the utricular macula project into a membrane containing otoliths.E Depolarization of a sensory cell occurs if the stereocilia are displaced away from the kinocilium.