Auditory Signal Transduction _ INNER EAR

Question 1

The organ of corti contains hair cells that:

Answer 1

generate a neural signal from the vibration of the basilar and tectorial membranes

Question 2

How many rows of outer hair cells are there within the cochlea in the inner ear:

Answer 2

three rows

Question 3

How many rows of inner hair cells are there within the cochlea in the inner ear:

Answer 3

one

Question 4

inner hair cells compose what percentage of auditory hair cells

Answer 4

5%

Question 5

inner hair cells are innervated by :

Answer 5

type I auditory neurons (1 IHC to many type I neurons)

Question 6

inner hair cells are responsible for :

Answer 6

transducing mechanical energy (movement of the basilar and tectorial membranes) into action potentials

Question 7

stereocilia are

Answer 7

hairlike extensions on the hair cells

Question 8

he tip of each stereocilium is connected to the side of its neighbour by a

Answer 8

tip link

Question 9

What does shear force on the stereocilia do?

Answer 9

pull on the tip links, which open ion channels and depolarise the hair cell

Question 10

outer hair cells represent

Answer 10

95% of auditory hair cells

Question 11

outer hair cells innervated by:

Answer 11

type II auditory afferent neurons (multiple OHCs to a single type II neuron)

Question 12

Outer Hair Cells (OHCs): OHCs are mainly innervated by Type II auditory nerve fibers. These connections are typically

Answer 12

one-to-many (one Type II neuron innervating multiple OHCs).

Question 13

Inner Hair Cells (IHCs): Each IHC is primarily innervated by multiple Type I auditory nerve fibers: ratio IHC to Type 1 neurons

Answer 13

multiple type 1 neurons for 1 IHC

Question 14

the tip links on OHCs depolarise the cell, but their primary function is

Answer 14

ot to send that signal to the CNS

instead, they dance

Question 14

the tip links on OHCs ___ the cell

Answer 14

depolarize

Question 15

What does the motile response of outer hair cells do?

Answer 15

amplifies and sharpens the movements of the basilar membrane

Question 16

cochlear amplifier:

Answer 16

the motile response of outer hair cells amplifies and sharpens the movements of the basilar membrane

Question 17

inner hair cells are responsible for

Answer 17

the transduction of sound to neural activity

Question 18

there are more outer hair cells than

Answer 18

inner hair cells

Question 19

outer hair cells have an important role in

Answer 19

amplifying and sharpening the frequency response of our hearing

Question 20

Frequency is represented by waht two things in the auditory system

Answer 20

place code
temproal code

Question 21

because of the frequency filtering properties of the basilar membrane, the location of an inner hair cell will

Answer 21

determine the frequency that it responds the strongest to

Question 22

inner hair cells fire with __ relative to the stimulus wave, creating a temporal representation of frequency

Answer 22

specific tmiing

Question 23

the frequency tuning of type 1 auditory neurons can be almost entirely accounted for by the

Answer 23

frequency response of the basilar membrane

Question 24

tonotopic organisation based on

Answer 24

frequency is maintained throughout the auditory system

Question 25

auditory neurons with higher characteristic frequencies have

Answer 25

sharper tuning curves

Question 26

cat neurons

Answer 26

repond to higher frequencies than humans can detect

Question 27

the temporal code for frequency arises from

Answer 27

the phase-locked responses of neurons to a sound stimulus

Question 28

neurons fires at a __

Answer 28

(time in the cycle) of the sine wave

Question 29

hase-locking occurs in auditory neurons up to

Answer 29

~ 5 kHz

Question 30

at higher frequencies, neurons are

Answer 30

not phase-locked to the stimulus

Question 31

a phase-locked response doesn't mean that it

Answer 31

fires every cycle of the sine wave

Question 32

a phase-locked response doesn't mean that it fires every cycle of the sine wave however, the activity of the population of neurons will have a

Answer 32

response at that frequency (and integer multiples of it)

Question 33

the intensity of a sound is also represented as both;

Answer 33

a rate code and the number of active hair cells

Question 34

as the sound intensity increases, a __ of the basilar membrane will move, meaning that more hair cells will be active

Answer 34

larger

Question 35

the firing rate of a type I auditory neuron will increase as

Answer 35

the intensity of the vibrations of the basilar membrane increase

Question 36

when that neuron reaches its maximum firing rate, the signal

Answer 36

saturates

Question 37

the different sensitivities of different hair cells allows

Answer 37

the encoding of a wide dynamic range

Question 38

Correct answers. the frequency of sound is represented with

Answer 38

both a place code and a temporal code

Question 39

neurons along the basilar membrane have a

Answer 39

tonotopic organisation

Question 40

inner hair cells with ___ generate action potentials that are phase-locked to the sound wave

Answer 40

inner hair cells with a low-moderate characteristic frequency generate action potentials that are phase-locked to the sound wave