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Flashcards in Audition Lec25 Deck (52):
1

what are the 3 divisions of the cochlear nuclei

the dorsal, posteroventral and anteroventral nuclei.

2

the whole range of ____ transduced by the cochlea is represented in each of its three nuclei. 

frequencies

3

one ___ = a sine wave

tone

4

oval window is smaller than tympanic
membrane --> 

20x pressure increase

5

lever action of ossicular chain -->
___x force increase

1.3

6

- from base to apex there is an increase in

width by a factor of 10

 

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7

- from base  to apex there is a decrease in

1. stiffness

2. frequency

3. conduction velocity

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8

how are hair cells at the apex compared to the base?

LESS stiff and LONGER

9

High frequency = higher amplitude = ___ distance traveled

shorter

10

___ frequencies go farthest on the basilar membrane

Low

11

Auditory receptor cells at each point along the basilar membrane respond to the amplitude of the traveling wave that ___

reaches it.

12

Hair cells spontaneously oscillate & are most sensitive to sound frequencies which 

match their oscillation frequencies

13

The ___ membrane is connected to the basilar membrane via the rigid limbus

tectorial

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14

Pushing up the basilar and tectorial membranes shears the cilia in one direction, which opens __channels and depolarizes the cell 

15

what is the normal potential difference between the sacla media and hair cell interior 

150 mV 

(scala media = 80 mV, hair cell interior = -70 mV)

16

what pushes K+ into hair cells? 

The scala media’s high (+) potential electrochemical gradient (150 mv)

17

what range of frequencies does the 3 cochlear nuclei receive?

each nucleus receives the full
range of frequencies

18

what type of pitch does the auditory cortex receive?

pitch patterns but necessarily pitch

19

Cochlear prostheses bypass the hair cells and excite the___

 appropriate nerve fibers.

21

general method of cohclear implants is to pass multiple electrodes into the ___

Scala Tympani.

23

The auditory system respond to a series of rapid fluctuations in______ brought about by the rarefaction and compression of air molecules.

 air pressure

25

the greater the magnitude of the amplitude of the sound the greater the 

Q image thumb

physical magnitude of the sound.

28

how much of the incident energy is transmitted at the oval window

1/1000

30

in decibals how much sound is lost by the time it reaches the oval window

30db

32

 

At the oval window, only about 1/1000 of the incident energy is transmitted.

 

To compensate for this loss requires an approximately ___ increase in pressure

32-fold

34

The 32-fold increase is accomplished in the ___ ear,

middle

36

The effective area of the tympanic membrane is about 60 square millimeters and that of the oval window about 3 square millimeters.

 

This results in a ___-fold increase in pressure at the oval window.

20

38

he force at the oval window is not equal to the force applied at the tympanic membrane but actually exceeds it by a factor of 

1.3.

40

As a result of forced applied at 1. the oval window 2. at the tympanic membrane

the pressure at the oval window is increased by a factor of ___

26.

42

with tympanometry

 In conductive hearing losses more sound is ____ then in the normal middle ear.

reflected

44

Pathologies that result in conductive losses:

1. otitis media

2. otoschlerosis

3. ear wax build up

46

the basilar membrane ___ in width as it runs from the base to the apex of the cochlea.

increases

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49

For equally applied forces along the membrane regions of lower stiffness will be displaced to a _____ degree.

Q image thumb

greater

51

The decreasing stiffness from base to apex results in an increase in___ from base to apex.

Q image thumb

 phase lag

53

As the stapes moves into the oval window a volume of the____is compressed.

 Scala Vestibuli 

55

the body compensates for the compression of the  Scala Vestibuli  by 

 bulging out of the round window.

57

downward bulge of round window is reet to a neutral position by the resotrative force provided by the

stiff base

61

the greater the frequency of the sound wave, the less the distance the 

traveling wave will move along the basilar membrane.

64

The character of the traveling wave, including its points of maximum deflection, is perfectly reflected in the 

pattern of discharges transmitted by the primary auditory neurons.

66

It turns out that the peak displacement of the traveling wave is actually very narrow, about the=

Q image thumb

 width of a few hair cells

68

where is the organ of corti?

the basialr membrane

70

___ houses the auditroy receptors

organ of corti

72

Pushing the basilar membrane and the tectorial membrane up will put a ___ action on the cilia in one direction 

shearing

74

Electrophysiological recordings have shown that there is a potential difference of +80 millivolts between the ___ and the ___

scala media and ground.

77

he inside of the hair cell is about ___ millivolts.

-70

79

Hair cells at different points along the basilar membrane differ from one another in their ___

electromechanical properties.

83

The frequency at which different hair cells oscillate differs according to their __

position along the basilar membrane.

85

____ is apparent in that each 8th nerve fiber terminates within the cochlear nuclei by branching to each of its three divisions: 

Parallelism

86

High frequencies are represented ___ in the nuclei

dorsally

87

 Within area AI, neurons of similar best frequency are arrayed 

 in a strip or belt-like
 

88

 Within area AI, neurons of similar best frequency are arrayed in a strip or belt-like
structure that runs perpendicular  to the___ axis.

 high-to-low
frequency tonotopic

89

 ___-dimensional spatial organization in
the auditory cortex.

three