Hearing

Question 1

What is the order of positioning of the hair cells and two membranes

Answer 1

Basilar on the bottom

Hair cells inbetween

Tentorial membrane on top

Question 1

Antibiotics and aspirin can effect hearing, how?

Answer 1

Damaging the outer hair cells

Question 2

What is the name of the cilia on the hair cells?

Answer 2

Stereocilia

Question 2

What must occur to the cilia for K channels to open?

Answer 2

They must move in the direction of the kinocilium

Question 2

What is the downstream effect of movement towards the kinocilium?

Answer 2

K channels open > K influx > Depolarisation of the cell > Ca channels open > Neurotransmitter is released

Question 2

What is special about the endolymph in the scala media?

Answer 2

It is high K - means there will be a K influx in response to channel opening

Question 2

Which hemisphere is speech usually processed?

Answer 2

Left

Question 3

Where does integration of sound signalling from both ears occur?

Answer 3

In the brainstem - particularly the superior olivary complex

Question 5

Sclerosis of the ossicles causes what?

Answer 5

Profound effects on hearing

Question 6

Compare the roles of the outer and inner hair cells?

Answer 6

Inner hair cells do must of the signal transduction for hearing while the outer ones amplify the movement of the membranes

Question 7

How do you localise low frequency sounds in the horizontal plane?

Answer 7

Measuring the time for sound to arrive at each ear

Question 7

T/F Must hearing loss has a known cause?

Answer 7

False

Question 9

Why do you need impedance matching?

Answer 9

Because transferring sound from air to fluid is usually prevented by reflection

Question 10

How is the auditory cortex organised?

Answer 10

Tonotopically - different areas are organised by the frequency they can process

Question 12

The amplitude of sound determines its what?

Answer 12

Loudness

Question 14

Through what do the ossicles transmit the vibrations from the tympani membrane to the inner ear?

Answer 14

Oval window

Question 15

In which inner ear chamber does most of the important events occur?

Answer 15

Scala media

Question 16

Which end of the basilar membrane deal with the high frequency sounds?

Answer 16

The base (lateral end)

Question 16

How do you localise high frequency sounds on the horizontal plane?

Answer 16

Measuring the difference in intensity

Question 17

Which hemisphere is music usually processed?

Answer 17

Right

Question 19

What is the function of the outer hair cells?

Answer 19

Amplify the amount of vibration of the basilar membrane in response to efferent signal

Question 20

What are the membranes of the inner ear?

Answer 20

Basilar

Tentorial

Question 21

The wavelength of sound determines its what?

Answer 21

Pitch

Question 22

Which neurotransmitter do the hair cells release?

Answer 22

Glutamate

Question 23

Which end of the basilar membrane deals with low frequency sounds?

Answer 23

Apex (medial end)

Question 24

What is the sequence of structures in the auditory pathway?

Answer 24

Hair cells > CNVIII > Cochlear Nucleus > Superior Olive > Lateral lemniscus > Inferior colliculus > Thalamus > Auditory cortex

Question 26

How are the cilia structured?

Answer 26

Shortest to tallest - the tallest is the most important

Question 28

Which type of antibiotic is particularly important in causing damage to outer hair cells?

Answer 28

Aminoglycosides

Question 29

What are the important parts of the superior olivary complex?

Answer 29

Lateral and medial superior olives and the trapezoid body

Question 30

What is impedance matching?

Answer 30

Translating the info as sound waves in air to waves in fluid