Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

!!!!! BRS YR2 !!!!! > Neuro - Auditory System > Flashcards

Neuro - Auditory System Flashcards

1
Q

How many sections is the ear generally divided into?

A

→ outer
→ middle
→ inner

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where is the auditory organ located?

A

embedded in the petrous portion of the temporal bone (hardest bone in body)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the functions of the outer ear?

A

→ captures sound and focuses it in the tympanic membrane
→ amplify some frequencies by resonance in the canal
→ protect ear from external threats (done by hair and wax)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the functions of the middle ear?

A

amplification by:
→ focusing vibrations from large surface area (tympanic membrane) to smaller surface area (oval window). The change in surface area means the pressure is increased.
→ Using leverage from the incus-stapes joint to increase the force on the oval window

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the hearing part of the inner ear?

A

cochlea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the function of the inner ear?

A

→ transduce vibration into nervous impulses

→ produces a frequency (or pitch) and intensity (or loudness) analysis of sound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 3 compartments of the cochlea when it’s uncoiled?

A

→ scala vestibuli
→ scala media
→ scala tympani

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the scala vestibuli and scala tympani?

A

bone structures, contain perilymph (high in sodium)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the scala media?

A

→ membraneous structure that contains endolymph (high in potassium)
→ contains the hearing organ / Organ of Corti
→ sandwiched between scala vestibuli and tympani

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What membrane contains the organ of Corti?

A

basilar membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is the basilar membrane arranged?

A

→ arranged tonotopically (thicker in one end, thinner the other) like a xylophone
→ base = narrow + tight
→ apex = wide + loose
→ sensitive to different frequencies at different points along length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the two types of hair cells in the Organ of Corti? How are they arranged?

A

→ inner hair cells, arranged in 1 column

→ outer hair cells, arranged in 3 columns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the purpose of the tectorial membrane in the Organ of Corti?

A

→ located above the hair cells
→ always in constant contact w OHCs, which assist in contact with IHCs
→ allows for hair deflection
→ this depolarises the cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the functions of IHCs?

A

→ carries 95% of afferent info of the auditory nerve

→ transduces sound into nerve impulses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the functions of OHCs?

A

→ carries 95% of efferent info of the auditory nerve

→ modulates sensitivity of the response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the hairs of the hair cells called?

A

stereocilia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does deflection of the stereocilia do?

A

→ mechanically opens the potassium open channels
→ ionic interchange = depolarisation of cell
→ neurotransmitter is liberated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does amplitude of sound affect deflection?

A

higher amplitudes (louder sounds) causes greater deflection of stereocilia, more hair cells involved, etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does hyper-polarisation of hair cells cause?

A

closes potassium channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the auditory pathway from cochlea to cerebral hemispheres?

A

→ spiral ganglions form each cochlea project via auditory vestibular nerve (VIII) to ipsilateral cochlear nuclei (monoaural neurones)
→ auditory info crosses at the superior olive level in brainstem
→ after this point, all connections are bilateral
→ goes through inferior colliculus and medial geniculate body in thalamus
→ ends in auditory cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What happens if a sound is too soft to cause deflection?

A

OHCs contract to bring the tympanic membrane closer to the stereocilia of the IHCs to cause deflection so sound can be heard

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What happens if a sound is too loud?

A

→ OHCs can elongate
→ pushes tympanic membrane away from stereocilia of IHCs
→ less deflection = less loud sound transduced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How is hearing arranged in the auditory cortex?

A

→ tonotopically organised (like a xylophone)

→ low freq to high freq anterior-posteriorly in the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is frequency / pitch? What is it measured in?

A

→ cycles per second, perceived tone

→ measured in Hertz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is amplitude / loudness? What is it measured in?

A

→ sound pressure
→ subjective attribute correlated with physical strength
→ decibels

26
Q

What is the human range of hearing for frequency?

A

20Hz - 20,000 Hz

27
Q

What is the human range of hearing for amplitude?

A

0 dB - 120 dB

28
Q

Why is the decibel scale useful?

A

→ log scale, so range of sensitivity is high
→ allows compression of scale onto a graph
→ reflects on idea that many physiological processes are on-linear

29
Q

How does hearing acuity change with age?

A

decreases with age, especially high frequencies

30
Q

How are medium + low frequencies affected through life?

A

progression of hearing loss

31
Q

What are the aims of a hearing assessment?

A

→ is there hearing loss?
→ what is the degree of hearing loss, if yes?
→ what is the type of hearing loss, if yes?

32
Q

What are the procedures used to test hearing during a hearing assessment?

A
  • Tuning fork
  • Audiometry
  • Central processing assessment
  • Tympanometry
  • Otoacustic Emission
  • Electrocochleography
  • Evoked potentials
33
Q

How and why is the tuning fork used?

A

→ Weber test or Rinne test
→ Used to establish the probable presence or absence of a hearing loss with a significant conductive component
→ provide early and general information, when audiometry is not available or possible

34
Q

What is PTA?

A

→ pure tone audiometry

→ science of measuring hearing acuity for variations in sound intensity and frequency

35
Q

What is a audiogram?

A

→ where hearing thresholds are plotted to define if there is a hearing loss or not
→ normal hearing threshold is located between 0-120dB

36
Q

What is an audiometer?

A

device used to produce sound of varying intensity and frequency

37
Q

What is a CPA?

A

→ central processing assessment
→ assessment of hearing abilities other than detection
→ verbal + non-verbal tests
→ examples: sound localisations, filtered speech, speech in noise

38
Q

What is the Weber test?

A

vibrate tuning fork at the top of the head to assess whether hearing loss (if any) is symmetrical

39
Q

What is the Rinne test?

A

compares direct stimulation of outer + middle ear with direct stimulation of the inner ear

40
Q

When is the tuning fork method used?

A

in GPs, usually when there’s no alternative method available at the moment

41
Q

What is tympanometry?

A

examination used to test the condition of the middle ear + mobility of the eardrum (tympanic membrane) + the conduction bones by creating variations of air pressure in the ear canal

42
Q

What are OAEs? Why are they tested?

A

→ normal cochlea produces low-intensity sounds called OAEs
→ sounds are produced specifically by OHCs as they expand and contract
→ often part of the newborn hearing screening and hearing loss monitoring.

43
Q

What are auditory evoked potentials? What are 3 most common types that clinics look for?

A

action potentials evoked by auditory stimuli:
→ electrocochleography
→ ABR (auditory brainstem response)
→ late response

44
Q

What is electrocochleagraphy?

A

→ 0.2-4.0 ms
→ electrical activity from the cochlea and eighth nerve
→ evoked by clicks or tone burst

45
Q

What is ABR (auditory brainstem response)?

A

→ 1.5-10.0 ms
→ electrical activity from the eighth nerve and brainstem nuclei and tracts (auditory pathway)
→ ABR is more commonly used in clinic
→ evoked by clicks
→ does not require attention from patient

46
Q

What are late responses?

A

→ 80-500+ ms
→ electrical activity from the primary auditory and association cortex
→ evoked by tone burst and oddball paradigm

47
Q

What do alterations in latency of waves show?

A

can point to the location of the deficit

48
Q

What are cortical potentials useful?

A

useful in investigations of neurological conditions or processing problems

49
Q

What are the 3 types of hearing loss?

A

→ conductive hearing loss
→ sensorineural hearing loss
→ mixed hearing loss

50
Q

What is conductive hearing loss?

A

problem is in outer + middle ear

51
Q

What is sensorineural hearing loss?

A

problem is in inner ear or auditory nerve

52
Q

What is mixed hearing loss?

A

→ conduction + transduction of sound are affected

→ more than one part of the ear is affected

53
Q

What are the different degrees of hearing loss?

A 
→ normal
→ mild
→ moderate
→ severe
→ profound
54
Q

What are some of the causes of conductive hearing loss affecting the outer ear?

A

→ wax

→ foreign body

55
Q

What are some of the causes of conductive hearing loss affecting the middle ear?

A

→ otitis

→ otosclerosis

56
Q

What are some of the causes of sensorineural hearing loss affecting the inner ear?

A

→ presbycusis

→ ototoxicity

57
Q

What are some of the causes of sensorineural hearing loss affecting the nerve?

A

8th cranial nerve tumour

58
Q

What are the different treatments for hearing loss?

A

→ underlying cause
→ hearing aids
→ cochlear implants
→ brainstem implants

59
Q

What is the main purpose of hearing aids?

A

amplifies sounds but doesn’t replace any specific structure

60
Q

What is the main purpose of cochlear implants?

A

replaces functions of hair cells by receiving sound, analysing it + transforming it into electrical signals + sending an electric impulse directly to the auditory nerve

61
Q

What does a cochlear implant need in order to function?

A

needs a functional auditory nerve

62
Q

What is the main purpose of a brainstem implant?

A

→ when the auditory nerves are the affected structures, the electrical signals can be sent to a set of electrodes directly into the brainstem
→ very risky, advised for people w bilateral important auditory nerve damage

!!!!! BRS YR2 !!!!! (72 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions