Auditory Pathways Flashcards
how is auditory information received?
by cochlear nucleus by fibers in the cochlear nerve
fibers from the cochlear nerve enter the brainstem where and then do what?
at the cerebellopontine angle and then split into ascending and descending bundles
where does the ascending bundle synapse at?
at the anterior part of the anterior cochlear nucleus
where does the descending bundle synapse at?
the posterior part of the anterior cochlear nucleus and posterior part of the posterior cochlear nucleus
what are the monaural tracts important for?
information about sounds at a single ear
what are the binaural tracts important for?
manages information about differences between sounds at both ears
central deafness is defined as damage to what?
the central pathways- everything from the cochlear nuclei up
central deafness rarely results in what?
in ipsilateral deafness–> people are not actually deaf, they are just unable to identify where the sound is coming from
what is sensorineural deafness?
damage to the cochlea or cochlear root of CN VIII
what is the presentation of sensorineural deafness?
ipsilateral deafness of structure affected
what could cause sensorineural deafness?
antibiotics, tumors, or repeated exposure to loud noises
what is conduction deafness?
obstructed or altered transmission of sound to tympanic membrane or through ossicle chain of middle ear
what could cause conduction deafness?
damage to pinna, excess ear wax, damage to tympanic membrane
what is the blood supply of the cochlea and auditory nuclei of the pons and medulla?
basilar artery
what is the blood supply of the inner ear and cochlear nuclei?
internal auditory artery
what does occlusion of the internal auditory artery result in?
monaural hearing loss with ipsilateral facial paralysis and the inability to look toward the side of the lesion
what is the blood supply of the superior olivary complex and lateral lemniscus?
short circumferential branches of the basilar artery
what is the blood supply of the inferior colliculus?
superior cerebellar and quadrigeminal arteries