The Ear Flashcards
what makes up the inner ear
cochlea and vestibular apparatus
what is Meniere’s disease
where theres too much fluid in the cochlea and vestibules giving the felling of spinning, that the ear is full and some hearing loss
what is benign paroxysmal positional vertigo
where there are short burst of vertigo due to crystals in the vestibular apparatus causing the fluid to move
what is sensorineural hearing loss
where there are problems in the inner ear, vestibulocochlea nerve of brain causing hearing loss
describe how vibrations are transmitted in the inner ear
the stapes transmits vibrations to the oval window causing fluid in the duct to move. this is sensed by the stereo cilia which then generate action potentials through CN VIII
what makes up the external ear
the pinna, external auditory meatus and lateral surface of the tympani membrane
what is the function of the eternal ear
collect the vibration and transmit and focus them down the meatus to the tympani membrane
describe the structure of the external auditory meatus
the outer 1/3 is cartilaginous and contains glands to produce wax and hair cells
the inner 2/3 is bony, through the temporal bone
what is ramsey-hunt syndrome
where there is reactivation of the chicken pox virus from the ganglia of the facial nerve causing vesicles in the external ear
what is pinna haematoma
where there is accumulation of blood between the cartilage and perichondrium of the pinna
what is the effect of pinna haematoma
the blood supply to the cartilage is from the perichondrium so can get avascular necrosis - this leads to fibrosis of the cartilage giving ‘cauliflower ears’
what do you treat a pinna haematoma
drain the blood and reposition the 2 layers
what is otitis externa
inflammation of the external auditory meatus
what makes up the inner ear
the 3 ossicles and the air filled space
what are the 3 ossicles called
malleus, incus and stapes
what do the ossicles do
transmit vibrations from the tympani membrane to the oval window of the cochlea (from an air to fluid medium)
what muscles are involved if the noises are too loud
contractions of tensor tympani and stapedius mean the the excessive vibrations don’t damage the ear
why can you become hypersensitive to loud noises with facial nerve problems
the facial nerve supplies tensor tympani and stapedius which dampen the effects of loud noises
what does the Eustachian tube do
allows for drainage of mucus
equilibrates the pressure of the middle ear with the atmosphere
what would happen is the Eustachian tube was blocked
the mucosa in the middle ear cavity would absorb the air creating a negative pressure - retracting the tympani membrane
there would also be no drainage of mucus produced
what is otosclerosis
fusion of the ossicles so vibrations won’t be transmitted causing deafness
what is Otitis media with effusion
where there is a blockage of the Eustachian tube causing a build up of negative pressure and fluid
how will the tympani membrane look in Otitis media with effusion
it will be retracted
what is acute otitis media
middle ear infection causing the build up of exudate in the middle ear cavity
what will the tympani membrane look like in acute otitis media
it will be bulging and could potentially be ruptured
what is mastoiditis
where a middle ear infection spreads to the air filled mastoid cells
what does mastoiditis look like
red, bulging mastoid process, pushing the ear forward
where could the infection spread in mastoiditis
venous structures and the brain
what is cholesteatoma
abnormal growth of skin in the middle ear
what is the symptom of cholesteatoma
foul smelling ear discharge
describe Rinne’s test
tap the tuning fork and place on mastoid process
repeat but then place over the ear
describe Weber’s test
tap the tuning fork and place on top of the head
with normal hearing what results would you expect in Rinne’s test
hearing the fork better when placed over the ear - as conduction through air is better then through bone
with normal hearing what results would you expect in Weber’s test
both ear would hear the noise equally
in sensorineural hearing loss what would you expect in Rinne’s test
the noise to be best heard over the ear
in sensorineural hearing loss what would you expect in Webers test
in the unaffected ear
in conductive hearing loss what would you expect in Rinne’s test
best heard when placed over the bone
in conductive hearing loss what would you expect in Weber’s test
best heard in the affected ear
what is conductive hearing loss
hearing loss which is cause by problems in the outer and middle ear
