Lecture 9 Flashcards
how many functional parts are there on the ear
3
name the 3 parts of the ear
inner outer and middle
what is the primary function of the outer and middle ear
conduction of sound to the inner ear
what is sound
pressure waves generated by vibrating air molecules
what is the medium for sound
air
sound consists of alternating ___ and ____
compressions and refractions
what is the the speed of sound
340 m/s
sound is converted from ___energy to ____electrical
mechanical , electrical
what is the range of that humans can hear sound
20 hz to 20k hz
which range of hearing is lost during old age
upper range
which hz are humans most sensitve to
3k
what is the range of human speech
3khz
what is the outer ear made out of
cartilage
what is the name of the most obvious component of the human outer ear
the auricle
what is the main function of the auricle
a reflector to capture sound and to fouus it into the external auditory meatus or ear canal
t/f the outer ear is not uniformly effective for capturing sound from any direction
true w
where does the external auditory meatus end
at the tympanic membrane
what is another name for the ear drum
typanic membrane
which part of the ear gathers sound energy and focuses it on the eardrum
the outer ear
which part of the ear boosts pressure of sounds in the human speech range
the outer ear
name this part of the ear: an air filled pouch extending from the pharynx
the middle ear
the middle ear is connected to the the ____ by the _____ tube
pharynx , eustachian tube
what is the name of the 3 tiny bones in the ear
the malleus , incus, stapes
what is the base of the malleus attached to
the tympanic membrane
what kind of energy is derived from sound
mechanical energy
what is another name fro the bones in the middle ear
the ossicles
what is the function of the ossicles
they convert air vibrations into fluid vibrations
what happens to the oscicles during lound noises
muscles stiffen the ossicles during loud noises
t/f sound travels from outer ear, middle ear into inner ear
true
t/f sound can go through bone to reach the inner ear
true
which is faster: conduction of sound through air or through bone
air
what are the 2 way that sound can get into the inner ear
conduction through bone or through air
t/f the chochlea is about the size of an apple
false , its about the size of a chickpea
what does the interior of the choclea contain
3 fluid filled tubes
the upper most fluid filled compartment of the inner is called?
the scala vestibuli
what is the at the base of the scala vestibuili
the oval window
what is the oval window sealed by
the stapes
what is the name of the lowermost part of the chambers in the inner ear
the scala tympani
what is the name of the middle fluid filled tube in the inner ear
scala media
what is another name for the scala media
the choclear duct
where is perilymph found
in the scala vestibuli and the scala tympani
where is endolymph found
in the scala media
t/f perilymph is high in potassium
false , endolypmph is high in potassium
t/f endolymph is found in the scala tympani
false, its found in the scala media
which part of the ear is used in balance
the semicircular canals
what does movement i the stapes cause
fluid inside the choclea to move
the oval window is where the _____ touches
stapes
what is the organ of corti
the receptor organ in the inner ear ,containing hair cells and supporting cells
about how many hair cells are there on each cholea
16000
what are hair cells innervated by
30,000 afferent nerve fibers
what is the function of hte nerve fibers in the organ of corti
they carry information into the brain along the 8 crainial nerve
in the inner ear, what does sound vibrate
the basilar membrane
what kind of the motion does the basilar membrane make
it vibrates back and forth
t/f the the tectorial membrane moves as teh the basilar membrane vibrates
false, it does not move
what are hair cells connected to
the tectorial membrane
how are the hair cells connected to the tectorial membrane via what
stereocilia
what happens to the stereocilia if the basilar membrane vibrates too much
the steriocilia come off
do sterocilia regenerate
no
when he basial membrane vibrates what happens to the sterocilia
they move back and forth
how are stereocila connected to each other
via tip links
what is the function of the tip links
they ensure that when stereocilia moves they all move
what kind of channels do tip links up by pulling up
k channels
the potassium channels that open due to movement of tip links are facing the perilymph or endolymph
endolymph
t/f endolyph is k poor and n rich
false , n poor and k rich
when the k channels open does k enter or leave the hair cell
enter
when k enters the hair cell does depolarization or hyperpolarization occur
depolarization
when depolarization occurs in a hair cells what is released
glutamate
when glutamate is released from a depolarized hair cell what occurs
neurons are activated which signal to the brain
t/f outer hair cells use stereocilia to sense vibrations and detect sound
true
t/f both outer and inner hair cells send signals to the brain
false only inner hair cells do this
how do outer hair cells send signals
they use electrical signals to change length in arallel with the sound signals
what is the overall affect of outer hair cells
to mechanically amplify sound
describe what the basilar membrane looks like
it is narrower and stiffer at the base and wider and more flexible at the apex
do all parts of the baislar membrane vibrate at he same frequency
no
what the shape of the basilar membrane give rise to
tonotopy
what is the function of the superior olive
it circulates the location of sound
where does crossover of information occur
at the superior olive
what is the function of the inferior colliculus
it orients head to sound
what are the 2 methods that calculate the location of a source of sound
- lateral superior olive
2. medial superior olive
what is the function of the lateral superior olive
it detects intensity differences
is the lateral superior olive better with low or high intensity sounds
high freq
is the medial superior olive good for low or high frequency sounds
low
how does the LSO calculate the interaural intensity difference
each LSO inhibits the other LSO . the ear hearing the louder sound wins
what does the inferior colliculus contain
an auditory map of space
what is the main function of the inferior colliculus
it is used orienting the head to the sources of sound
name this part of the ear : a relay station for auditory information going to the cortex
the medial geniculate nucleus
where does the primary auditory cortex send output to
the second auditory input
how is each auditory area organized
tonotopically
how can cortical tonotopy be changed
early exposure to a tone or behavior training
in which hemisphere is the wernikes area found
in the left hemisphere
any hearing loss is called
deafness
how many types of hearing loss are there
2
what are the 2 types of hearing loss
conductive and sensorineural
describe conductive hearing loss
damage to the outer ear or middle ear
damage to the outer or middle or ear is call
conductive hearing loss
is a choclear implant used for conductive hearing loss
no
what is sensorineural hearing loss
damage to the inner ear , nerves or auditory parts of the brain
