Hearing 2

Question 1

Parts of the ear?

Answer 1

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Question 2

Purpose of the outer ear?

Answer 2

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Question 3

Wax function?

Answer 3

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Question 4

Middle ear contents?

Answer 4

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Question 5

Eustachian tube?

Answer 5

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Question 6

Eustachian tube in infants?

Answer 6

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Question 7

Why do wee need a middle ear?

Answer 7

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Question 8

How does the middle ear carry out its function?

Answer 8

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Question 9

Diseases of middle ear?

Answer 9

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Question 10

Inner ear structure?

Answer 10

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Question 11

Cochlear structure and fluids?

Answer 11

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Question 12

Organ of corti?

Answer 12

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Question 13

How is the travelling wave formed?

Answer 13

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Question 14

Mechanoelectrical transduction in hair cells?

Answer 14

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Question 15

Excessive noise on hair cells?

Answer 15

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Question 16

Mechanisms of amplification in inner ear?

Answer 16

Response is practically instantaneous due to no intermediary

• Scala tympani has a pump that passively removes K+ which is important as it means a limited vascular supply is needed to this region (so we don’t hear blood flow)

Question 17

Meineirs disease?

Answer 17

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Question 18

How is potassium recycled in endo lymph?

Answer 18

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Question 19

Hair cells functions?

Answer 19

25% IHC

OHC - a. Motor proteins (‘prestin’) in the plasma membrane contracts (active process)

b. Sound stimulation causes these cells to oscillate in a frequency specific manner which helps amplify the motion of the basilar membrane at certain locations along its length* (cochlear amplifier)
c. As such the travelling wave is actively amplified by OHC contraction which helps overcome the viscous forces of fluid and resistance of tissue (boosts sound by 60-70dB)

Question 20

Sensorineural hearing loss

Answer 20

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