Hearing Flashcards Preview

BMS1052 Human Neurobiology > Hearing > Flashcards

Flashcards in Hearing Deck (6):
1

Are the inner hair cells and the ganglion cells they lead to spiking or non spiking?

The inner hair cells are non-spiking, while the ganglion cells are spiking.

2

What does the rate of action potential in hair cells depend on?

If the cells are tipped to their maximum towards the shortest hairs, all the possible potassium ion channels are closed and there is no further hyperpolarisation. When they are tipped to their maximum towards the longest, all the possible potassium ions channels are closed and their is no more depolarisation.

3

What is the role of the outer hair cells?

Receive input from the cortex and adjust their shape to alter the efficiency of the inner hair cells and their rate of action potential in response to varying frequencies and intensities.

4

Why is sensitivity to high frequencies most likely to be affected by deafness?

The base is most sensitive to high frequencies. All sounds pass the base and so it is likely to be damaged.

5

Even in absolute silence there are still APs in all auditory nerve fibres to the brain because:
Select one:
a. the eardrum is always vibrating by a small amount.
b. the outer hair cells are always releasing transmitter to these nerve fibres.
c. there is a standing current flow through some open ion channels in hair cell stereocilia. Correct
d. the nerve fibres can control the transmitter they release.
e. K+ ions are entering the afferent fibres, through open ion channels.

There is a standing current flow through some open ion channels in hair cell stereocilia.

6

Opening of ion channels in the stereocilia of hair cells of the cochlea:
Select one:
a. allows the movement of K+ ions down their concentration gradient.
b. allows the movement of K+ ions down their electrical gradient. Correct
c. allows the movement of both Na+ and K+ ions
d. allows the movement of Na+ ions down their electrical gradient.
e. results in the hyperpolarization of the membrane potential of the hair cells.

Allows the movement of K+ ions down their electrical gradient.