Auditory system

Question 1

What is a ‘beat’?

Answer 1

A
an overlay between 2 frequencies
have areas where 2 waves are in phase, constructive interference –> hear sound
have areas where 2 waves are not in phase, destructive interference –> do not hear a sound

Question 2

Birds have a scala media, a scala vestibuli, and an oval window.

A. true
B. false

Answer 2

true

Question 3

Mammals have…

A. an external ear canal
B. a middle ear
C. a Tympanic membrane
D. a cochlea and a vestibular organ
E. all of the above

Answer 3

e

Question 4

What is the hearing range for speech (in dB) and why is it important?

Answer 4

0-20dB

Question 5

What are the components of the organ of corti?

Answer 5

Scala tympani
Scala vestibuli
Scala media

Question 6

The outer hair cell is involved in activating APs while the inner hair cell is involved in amplification.

A. true
B. false

Answer 6

B. false

The outer hair cell is actually involved in amplification while the inner hair cell is involved in activating APs .

Question 7

Select the true statements.
In outer hair cells…

A. a contracted cell –> depolarization
B. a contracted cell –> hyperpolarization
C. an elongated cell –> depolarization
D. an elongated cell –> hyperpolarization
E. the function is to amplify mechanical signals

Answer 7

A. a contracted cell –> depolarization
D. an elongated cell –> hyperpolarization
E. the function is to amplify mechanical signals

Question 8

In damage due to hearing loss, the outer hair cells are the first to be damaged, and the sound must be much louder to get the same sensation as in a normal hearing patient. What shift in dB does this damage cause

Answer 8

a shift of around 40 dB

Question 9

In diagnostics…

A. if you’re using bone conduction, the sound is transmitted via the middle ear
B. if you’re using air conduction, the sound is transmitted via the middle ear
C. if you’re using bone conduction, the sound is not transmitted via the middle ear, only via bones –> cochlea
D. if you’re using air conduction, the sound is not transmitted via the middle ear, only via bones –> cochlea

Multiple answers possible

Answer 9

B. if you’re using air conduction, the sound is transmitted via the middle ear
C. if you’re using bone conduction, the sound is not transmitted via the middle ear, only via bones –> cochlea

Question 10

What is correct about mechanical-electrical transduction in inner hair cells?

A. mvmt towards biggest cilia = depolarization
B. mvmt towards smallest cilia = hyperpolarization
C. depolarization decreases frequency

Multiple answers correct
D. hyperpolarization is inhibitory
E. all of the above

Answer 10

A. mvmt towards biggest= depolarization
B. mvmt towatrds smallest = hyperpolarization
D. hyperpolarization is inhibitory

Question 11

What of the following regarding loudness coding is true?

A. it already takes place at the auditory nerve
B. may be tonic –> constant response, stable level over time
C. may be phasic –> additional excitation at the beginning of the stimulus, inhibitory at the end
D. assess the number of APs taking place at 1 single nerve fiber
E. all of the above

Answer 11

e.

Question 12

Why is phasic coding important?

Answer 12

It takes place because the cell may be damaged if an AP stays constant at a too high level for too long
-part of adaptation

Question 13

Select the true statements.

A. frequency coding occurs by location only
B. frequency coding occurs by phase locking only
C. frequency coding can occur by location, but is mostly done by phase locking
D. frequency coding is done by phase locking and by location
E. in humans, location is mainly responsible for frequency coding

Answer 13

e

Question 14

In the cochlear nucleus, what cells are found in the Dorsal cochlear nucleus and what cells are found in the Anteroventral cochlear nucleus?

Answer 14

Dorsal cochlear nucleus
-fusiform cells

Anteroventral cochlear nucleus

bushy cells
stellate cells
octopus cells

Question 15

The ventral thalamus is a relay structure for frequency, intensity, and duration of an auditory signal.

A. true
B. false

Answer 15

A. true

Question 16

What is tinnitus?

Answer 16

an overrepresentation/misrepresentation of a certain frequency
phantom sound
conflicts in the analysis of sound features
an unexplained constant buzzing/ringing sound
neural plasticity and overrepresentation

Question 17

Describe what happens at each of the following structures of the lower auditory pathway:

cochlear nucleus
olivary system
midbrain (lateral lemniscus, inferior colliculus)

Answer 17

cochlear nucleus
- receives input from the same side
- differentiation of sound features
olivary system
- receives input from both ears to localize the sound
midbrain (lateral lemniscus, inferior colliculus)
- integration of all sound features
- inhibition of auditory reflexes (behavioural)

Question 18

Describe what happens at each of the following structures of the higher auditory pathway:

medial geniculate body (thalamus)
auditory cortex

Answer 18

medial geniculate body (thalamus)
- relay stations for different perception tasks (eg. communication, fear, stress)
- connected to different areas (hippocampus, amygdala)
auditory cortex
- perception of sound
- connects to contralateral auditory cortex/hemisphere

Question 19

The semicircular canals are responsible for the detection of angular velocity.

A. true
B. false

Answer 19

A. true

Question 20

Select all the true statements.

A. In the vestibular system there are also hair cells, categorized as type I and type II cells
B. Type I cells are smaller
C. Type II cells are bigger
D. Hair cells are deflected during head movements
E. Type II cells modulate responses during head movements

Answer 20

A. In the vestibular system there are also hair cells, categorized as type I and type II cells
D. Hair cells are deflected during head movements
E. Type II cells modulate responses during head movements

Question 21

Describe the perception of gravity in relation to the vestibular system

Answer 21

receptors detect linear acceleration (eg. gravity)
hair cells in the sacculus - responsible for vertical plane
in the utricle - horizontal plane
if these hair cells are lost, they do not regenerate.
detection of gravity involves Otoconia

Question 22

What are Otoconia?

Answer 22

otoconia are calcium carbonate stones coupled to sensory hair cells in the ultricle and saccule - are essential to sense linear acceleration and gravity for the purpose of maintaining bodily balance
loss of these stones from the utriculus –> most common disease, affects the posterior semi-circular canal

Question 24

What is the process that occurs if the ear is overstimulated?

Answer 24

1st outer hair cells are lost due to their close connection with the tectonic membrane
prolonged exposure leads to the loss of inner hair cells –> deafness
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Question 25

Which of the following are true?

A. noise induced hearing loss is often accompanied by a loss of discrimination ability
B. noise induced hearing loss is not often accompanied by a loss of discrimination ability
C. improving discrimination ability can be easily done with hearing aids
D. noise exposure can lead to remarkable changes in physiology within the central auditory pathway

Answer 25

A. noise induced hearing loss is often accompanied by a loss of discrimination ability
D. noise exposure can lead to remarkable changes in physiology within the central auditory pathway

Question 26

Why is Manganese-enhanced 7-tesla-MRI a smart method?

Answer 26

Flashcards
A
a good way to structurally image because manganese ions easily cross the BBB and agonise the Ca2+ influx into the cell during pre-synaptic activaition
the resulting MRI-T1 signal contrast depends largely on intracellular concentraction of manganese ions which show a slow clearance over time
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Q

Question 27

What decibel level is considered to cause deafness?

Answer 27

> 100 dB

Question 28

What are potential causes of inner ear related hearing loss?

Answer 28

congenital (eg. connexin mutation)
infection (eg. meningitis)
accident (eg. temporal bone fracture)
noise

Question 29

Endolymph is found in..

Answer 29

Scala Media and semicircular canals and the utricle and saccule of the vestibule.

Question 30

Perilymph is found in

Answer 30

scala vestibuli (above) and the scala tympani (below) within the cochlea and vestibule