auditory function and balance Flashcards
deafness: list the causes of conductive and sensorineural deafness
describe pathogenesis of conductive hearing loss
when ear is not capable of transmitting vibration of sound waves onto cochlea
what 3 things can all affect transmission of vibration onto cochlea
cerumen (earwax), infections e.g. otitis, tumours
what is a common cause of conductive hearing loss in children
fluid accumulation e.g. with a cold
what can be perforated, causing conductive hearing loss
tympanic membrane
what can obstruct the ear canal, causing conductive hearing loss
abnormal growth of osccile bones (otosclerosis)
what is a temporary form of conductive hearing loss
barotrauma
how is a barotrauma treated
Valsalva maneuver to reopen the Eustachian tubes
describe sensorineural hearing loss
hearing loss when problem is rooted in sensory apparatus of inner ear or in vestibulocochlear nerve (retrocochlear hearing loss)
how common is sensorineural hearing loss
most widespread type of hearing loss
5 sensory causes of sensorineural hearing loss
loud noises, many genetic mutations which affect Organ of Corti, aminoglycoside antibiotics (toxic for hair cells), congenital diseases (e.g. Meniere's, rubella, toxoplasmosis), ageing (presbycusis)
2 neural causes of sensorineural deafness
acoustic neuroma (tumour on the cochlear nerve), viral infection
what is hearing loss primarily due to
loss of hair cells, which do not regenerate
solution to hearing loss due to loss of hair cells
cochlear implant
how does a cochlear implant work
elongated coil inserted into cochlea, with pairs of electrodes corresponding to
single frequencies, which bypass dead cells and stimulate nerve fibres directly, so detect sounds, break them down into constituent frequencies, and send signal directly to auditory nerve via antenna
2 limitations of cochlear implants
not enough antennas to replace hair cells, and no active processes
