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Jason's Neuro Block > Hearing > Flashcards

Flashcards in Hearing Deck (34):
1

what 3 things are being detected by ears?

1. wavelength: pitch
2. amplitude: loudness
3. waveform - tone/timbre

2

Function of ossicles?

matches air vibrations to fluid in inner ear

3

tympanic membrane amplifies how much compared to inner ear??

200 fold

4

3 chambers of cochlea?

1. scala vestiboli
2. scala media
3. scala tympani

5

Basilar membrane is wider where? what does it detect?

wider at the base (detect high freq)

6

apex of basilar membrane detects?

apex detect low freq

7

how is basilar membrane organized?

tono-topically

8

What is the organ of Corti?

what transduces sound waves to neural impulses

9

auditory hair cell found between?

basilar membrane and tectoral membrane

10

each hair cell have how many stereo cilia?

100

11

how do you trigger auditory transduction?

basilar membrane vibrates> create shear forces on tectorial membrane> depolarize hair cells

12

Hair cells use what ions to depolarize?

Potassium (K+)

13

deflection of hair bundle toward kinocilum? away?

towards: depolarization (Ca2+ influx>glutamate)
away: hyperpolarization

14

hair cell potassium channels are usually closed?

nope. partially open

15

Are the hair cells depol and hyperpol amounts equal if the movement is equal?

Nope. larger depol

16

Normal neurons has influx of what ion?

Na+

17

what makes the potential difference in the cochlea re: ions?

Endolymph at +80mV (High K+)
Perilymph is at 0mV (Low K+)

18

cell connections in inner ear are called?

vasa vascularis

19

what's the difference between inner and outer hair cells?

inner: 95% to brainstem nuclei
outer:
1. enhances tectorial membrane movement
2. efferent inputs from superior olivary complex

20

how does outer hair cell affect inner hair cells?

low intensity stim>outer change length>increase basilar membrane movement>amplify to inner hair cells

21

depol and hyperpol of outer hair cells causes what?

depol: contraction
hyperpol: elongation

22

outer hair cells can be affected by what drugs?

aminoglycosides (gentamycin)
aspirin
ototoxicity

23

without outer hair cells, how much less does the inner hair cells detect?

100 fold less

24

Auditory pathway starting at hair cells:

Hair cells>CNVIII>spiral ganglion>cochlear nucleus>decussation>superior olive>lateral lemniscus>inferior colliculus (midbrain)>medial geniculate nucleus of thalamus>auditory cortex

25

what does the anteroventral cochlear n. and superior olivary complex do?

mediate sound localization (horizontal plane)

26

superior olivary complex consists of 3 things:

1. lateral superior olives
2. medial superior olives
3. trapezoid body

27

2 ways to localize sound: know as what theory?

1. time difference
2. intensity difference
Duplex theory

28

Time difference for sound localization works well particularily with what?

low frequency sounds

29

what detects the Time difference for sound localization?

medial superior olive

30

intensity difference for sound localization for what kind of sound?

high frequency

31

intensity difference for sound localization, how does the MNTB come into play?

MNTB: medial nucleus of trapezoid body inhibits contralateral LSO (lateral superior olive) excitation

32

What is in brodmann's area 41?

Herschls Gyrus (tonotopic)

33

Higher order of auditory processing: which hemisphere for:
1. speech
2. music
3. environmental?

1. left
2. right
3. both

34

3 causes of hearing loss within 3hr to 3 days include?

1. peripheral: guillan-barre, cancer
2. central: MS
3. cochlear:infection, trauma, ototoxicity, vascular