Lecture (3/21) week 9 Thursday Flashcards
T/F
The OHC cochlear amplifier helps tune the wave
true
why do the outer hair cells contract and expand?
to provide a boost to the basilar membrane
outer hair cells contract when the BM…
goes up
outer hair cells elongate when the BM…
goes down
the OHC cochlear amplifier acts a _____ device
sharpening
is the OHC cochlear amplifier considered an active or passive mechanism?
active mechanism
when acoustic frequencies enter the ear canal, they vibrate ____ and _____
the TM and the ossicles
If the frequency is 1000 Hz, how many vibrations do the ossicles and TM undergo?
1000 vibrations
If the frequency is 1000 Hz, how many times does the stapes footplate push in and out of the oval window?
1000 times per second
where is frequency encoded on the basilar membrane?
the place that is maximally displaced
movement creates stereocilia ____ and ____
stereocilia shearing
graded potentials
T/F complex sounds result in multiple places of maximum displacement at the same time
true
T/F the BM is divided into 2mm bandpass filters that let through a band of frequencies
true
apex of bm correlates to ____ frequencies
low
base of bm correlates to ____ frequencies
high
the louder the sound the _____ the displacement on the TM, ossicles, and stapes footplate in the oval window
greater
the higher the displacement of the BM in response to a traveling wave, the more hair cells that are activated and more _______ sent
graded potentials
high intensities= more hair cells=_____ graded potentials
more
low intensities= fewer hair cells=____ graded potentials
fewer
what causes graded potentials?
depolarization
depolarization only takes place when…
basilar membrane moves up
basilar membrane moves up during rarefaction or compression?
rarefraction
what degrees is the tympanic membrane moving up?
270
what degrees in the sound wave is causing graded potentials?
270
