I’m Deaf

Question 1

What does the pinnacle do?

Answer 1

Collect sound

Question 2

What are the names of the three ossicles?

Answer 2

Malleus, incus, and stapes

Question 3

What is the eardrum called?

Answer 3

Tympanic membrane

Question 4

What do the ossicles do for the tympanic membrane?

Answer 4

Creates movement and causes more pressure to vibrate the cochlear fluid than the air could provide (amplifier)

Question 5

What are the three fluid filled chambers in the cochlea called?

Answer 5

Scala vestibuli, Scala media, Scala tympani

Question 6

What separates the Scala vestibuli and Scala media?

Answer 6

Reissner’s membrane

Question 7

What separates the Scala media and Scala tympani?

Answer 7

Basilar membrane

Question 8

Where is the organ of corti?

Answer 8

On the basilar membrane (media side)

Question 9

What is the importance of the organ of corti?

Answer 9

It contains the auditory receptor cells

Question 10

What hangs over the organ of corti that helps stimulate the hair cells?

Answer 10

Tectorial membrane

Question 11

What are the chambers that contain perilymph?

Answer 11

Scala vestibuli and Scala tympani

Question 12

What are the chambers that contain endolymph?

Answer 12

The Scala media

Question 13

What are the ion concentrations in the perilymph?

Answer 13

High Na+ Low K+

Question 14

What are the ion concentrations in the endolymph?

Answer 14

High K+ and Low Na+

Question 15

What causes the ionic difference?

Answer 15

Stria vascularis

Question 16

What is the helicotrema?

Answer 16

Hole at the apex of the basilar membrane that connects vestibuli and tympani

Question 17

Where does the stapes push on the cochlea?

Answer 17

Oval window

Question 18

What is a tonotopic map?

Answer 18

A place code on the basilar membrane that produced maxes amplitude deflection

Question 19

What do the tips of stereocilia of hair cells touch?

Answer 19

Tectorial membrane

Question 20

What do the outer hair cells bend in response to?

Answer 20

Tectorial membrane

Question 21

What do the inner hair cells bend in response to?

Answer 21

Moving endolymph

Question 22

Stereocilia have ____ gated ion channels

Answer 22

Mechanically

Question 23

What causes when the hair cells are bent the correct way?

Answer 23

K+ channels are forced open which depolarizes the cell

Question 24

Once hair cell is depolarized, what happens?

Answer 24

Ca2+ enters and causes NT transmission onto a nerve cell

Question 25

What is the ratio of outer hair cells to inner hair cells?

Answer 25

3:1

Question 26

What do the inner and outer hair cells communicate to?

Answer 26

Spiral ganglion cells

Question 27

What percent of spiral ganglion neurons communicate w/ inner hair cells?

Answer 27

95%

Question 28

One inner hair cell usually has ____ spiral ganglion attached

Answer 28

10

Question 29

How many spiral ganglion receive input from several outer hair cells?

Answer 29

1

Question 30

What is the purpose of outer hair cells?

Answer 30

Amplifying movement of the basilar membrane w/ low intensity sounds

Question 31

What protein is responsible for outer hair movements?

Answer 31

Prestin

Question 32

What happens if there’s no Prestin?

Answer 32

Near deafness

Question 33

What is the central auditory pathway?

Answer 33

Ventral cochlear nuclei -> superior olive -> inferior colliculus -> MGN -> Aud cortex

Question 34

When do binaural neurons first appear?

Answer 34

Superior olive

Question 35

What do the Olivary nucleus use to travel to the inferior colliculus?

Answer 35

Lateral lemniscus pathway

Question 36

IC projects to the ____

Answer 36

MGN in the thalamus

Question 37

The MGN project to the ____

Answer 37

Auditory cortex

Question 38

What is the characteristic frequency of a hair cell?

Answer 38

What frequency it is most responsive to

Question 39

Does greater amplitude of a sound cause more of less depolarization?

Answer 39

More, which leads to APs being fired at an increased rate

Question 40

What kind of sound produces basilar membrane movements over a longer distance? (Aka activates more hair cells)

Answer 40

Intense sounds

Question 41

What is loudness correlated with?

Answer 41

Number of active neurons and firing rates

Question 42

What encodes sound frequencies at <200Hz?

Answer 42

Phase locking (fire an AP at same cycle as sound)

Question 43

How are intermediate frequencies encoding with?

Answer 43

Phase locking and tonotopy

Question 44

What is the volley principle?

Answer 44

Intermediate sound frequencies display a pooled phase lock manner

Question 45

At <5 kHZ, what encodes sound frequencies?

Answer 45

Tonotopy

Question 46

What is interaural time delay?

Answer 46

Time diff from sound to hit one ear compared to another

Question 47

What is used to compare differences in each ear for continuous low tones? (20-2k Hz)

Answer 47

Time it takes for each CYCLE to hit the ear

Question 48

What is used to compare differences in each ear for continuous high tones (2k-20k Hz)?

Answer 48

Compared INTENSITY of the sound compared to both ears, whichever side is more intense is where the sound is coming from

Question 49

What determines vertical sound localization?

Answer 49

Reflection from the pinna

Question 50

How is the A1 structured?

Answer 50

Tonotopically

Question 51

Where do MGN neurons terminate in A1?

Answer 51

Layer 4

Question 52

What do Layers 2 and 3 of A1 contain?

Answer 52

Small pyramidal cells

Question 53

What do Layers 5 and 6 contain?

Answer 53

Mostly pyramidal cells