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Flashcards in Audition Lec25 Deck (52)
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1
Q

what are the 3 divisions of the cochlear nuclei

A

the dorsal, posteroventral and anteroventral nuclei.

2
Q

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

A

frequencies

3
Q

one ___ = a sine wave

A

tone

4
Q

oval window is smaller than tympanic
membrane --> 

A

20x pressure increase

5
Q

lever action of ossicular chain -->
___x force increase

A

1.3

6
Q

- from base to apex there is an increase in

A

width by a factor of 10

 

7
Q

- from base  to apex there is a decrease in

A

1. stiffness

2. frequency

3. conduction velocity

8
Q

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

A

LESS stiff and LONGER

9
Q

High frequency = higher amplitude = ___ distance traveled

A

shorter

10
Q

___ frequencies go farthest on the basilar membrane

A

Low

11
Q

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

A

reaches it.

12
Q

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

A

match their oscillation frequencies

13
Q

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

A

tectorial

14
Q

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

A

15
Q

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

A

150 mV 

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

16
Q

what pushes K+ into hair cells? 

A

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

17
Q

what range of frequencies does the 3 cochlear nuclei receive?

A

each nucleus receives the full
range of frequencies

18
Q

what type of pitch does the auditory cortex receive?

A

pitch patterns but necessarily pitch

19
Q

Cochlear prostheses bypass the hair cells and excite the___

A

 appropriate nerve fibers.

21
Q

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

A

Scala Tympani.

23
Q

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

A

 air pressure

25
Q

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

A

physical magnitude of the sound.

28
Q

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

A

1/1000

30
Q

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

A

30db

32
Q

 

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

A

32-fold

34
Q

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

A

middle

36
Q

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.

A

20

38
Q

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 

A

1.3.

40
Q

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 ___

A

26.

42
Q

with tympanometry

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

A

reflected

44
Q

Pathologies that result in conductive losses:

A

1. otitis media

2. otoschlerosis

3. ear wax build up

46
Q

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

A

increases

49
Q

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

A

greater

51
Q

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

A

 phase lag

53
Q

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

A

 Scala Vestibuli 

55
Q

the body compensates for the compression of the  Scala Vestibuli  by 

A

 bulging out of the round window.

57
Q

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

A

stiff base

61
Q

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

A

traveling wave will move along the basilar membrane.

64
Q

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

A

pattern of discharges transmitted by the primary auditory neurons.

66
Q

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

A

 width of a few hair cells

68
Q

where is the organ of corti?

A

the basialr membrane

70
Q

___ houses the auditroy receptors

A

organ of corti

72
Q

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

A

shearing

74
Q

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

A

scala media and ground.

77
Q

he inside of the hair cell is about ___ millivolts.

A

-70

79
Q

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

A

electromechanical properties.

83
Q

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

A

position along the basilar membrane.

85
Q

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

A

Parallelism

86
Q

High frequencies are represented ___ in the nuclei

A

dorsally

87
Q

 Within area AI, neurons of similar best frequency are arrayed 

A

 in a strip or belt-like
 

88
Q

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

A

 high-to-low
frequency tonotopic

89
Q

 ___-dimensional spatial organization in
the auditory cortex.

A

three