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Neurophysiology > Hearing > Flashcards

Flashcards in Hearing Deck (35):
1

How are wavelength and pitch linked?

As you decrease the wavelength, increase in pitch

2

What determines the amplitude of the signal? i.e. volume

The displacement of air

3

What is infrasound?

Anything lower than normal frequency that humans can hear "auditory threshold"

4

What is ultrasound?

Anything higher than the normal frequency that humans can hear

5

What is the name for the outer ear?

Pinna

6

Which bone is the tympanic membrane attached to?

Malleus

7

Name the 3 ossicles

Malleus
Incus
Stapes

8

What is a function of the muscles in the middle ear?

Turn down sensitivity to sound when it isn't required e.g. when eating

9

Which bone transmits sound waves from the middle ear to the cochlea?

Stapes

10

What is the name of the structure that the stapes pushes into?

Oval window

11

What are the main components of the inner ear?

Cochlea
Vestibule
Semi-circular canals

12

Where is endolymph found?

Scala media
Semicircular canals
Vestibule

13

Where is perilymph found?

Scala vestibule
Scala tympani

14

Where is endolymph produced?

Stria vascularis

15

What creates fluid waves within the cochlea?

Vibration of oval window

16

How do sound waves escape the cochlea?

Round window

17

Where are high and low frequencies detected?

High - base of basilar membrane
Low - apex of basilar membrane

18

What happens when the resonance frequency is activated?

Absorbs all the kinetic energy of the sound wave and effectively stops it at that point
Basilar membrane is pushed up and hair cells are displaced

19

Why is loss of hearing usually not recoverable?

Support cells do not differentiate well into hair cells

20

What is the role of outer hair cells?

Alter sensitivity of system which can tune the cochlea by amplifying select frequencies and dampen down areas of pitch of no interest

21

What happens when you stimulate outer hair cells?

They shorten and stiffen which puts a force through the rods of corti which moves the basilar membrane closer to the tectorial membrane

22

Which cells are responsible for hearing?

Inner hair cells

23

What is the function of the rods of Corti?

Maintains relationship between the hair cells and the basilar membrane

24

Describe signal transduction at the hair cell

Displacement of stereocilia opens potassium channel causing influx and depolarisation
Depolarisation opens calcium channels resulting in influx which causes vesicles to dock onto the synapse and release NT

25

What happens if hair cells move away from the tallest stereocilia?

Hyperpolarisation --> Inhibition

26

Where are the dorsal and ventral cochlear nuclei?

Upper medulla

27

Where do all auditory pathways project?

Medial geniculate nucleus

28

Which areas of the brain are involved in the arousal responses to noise?

Reticulum
Vermis

29

How is frequency mapped on the auditory cortex?

High frequencies posterior
Low frequencies anterior

30

Describe the process of shadow sound

Sound from one side hits the head, which then generates a shadow sounds on the other side of the head, in which the volume is less
Comparison of the signal intensities from both ears determines the ear closest to the sound

31

Describe the process of sound lag

Sound from a particular direction enters one ear before the other and so there is a slight delay between the sound arriving ipsilaterally at the auditory cortex and that arriving contralaterally

32

What causes conductive deafness?

Blockage or infection of outer ear
Rupture of tympanic membrane
Ossification of the small ones in the middle ear

33

What is the cause of sensoneural deafness?

Breakdown of cochlea
Damage to auditory nerve or cortex

34

What are the names of the 2 tests for deafness?

Rinnes
Webbers

35

What happens if you lose auditory cortex?

Loss of meaning of sounds as seen in those with Wernickes lesions