Brainscape's Knowledge GenomeTM

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


See full index

BRS YR2 > Auditory and Vestibular System > Flashcards

Auditory and Vestibular System Flashcards

1
Q

What makes up the outer ear?

A
  • pina

- external auditory meatus

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

What makes up the middle ear?

A
  • malleus
  • incus
  • stapes
  • eustachian tube
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What makes up the inner ear?

A
  • the vestibule
  • the semicircular canals
  • the cochlea.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the function of the inner ear?

A

transduction

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

What is Transduction?

A

conversion of one energy form to another

mechanical sound waves to electrical signals

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

What term is used to describe the arrangement of the basilar membrane?

A
  • tonotopic arrangement
  • high to low frequency from base to apex
    high frequency: tight and narrow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the auditory pathways to the brain?

A
  • cochlear nucleus
  • superior olive (bilateral)
  • inferior colliculus
  • medial geniculate body
    auditory cortex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does the middle ear amplify sound?

A
  • focuses vibrations from large SA (tympanic membrane) to small SA (oval widow), increasing pressure
  • leverage from the incus -stapes to increase the force on the oval window
  • malleus, incus and stapes articulate to facilitate the transmission of sound into the inner ear
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the three ossicles?

A
  • malleus
  • incus
  • stapes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does the inner ear transduce sound?

A
  • deflection of the stereocilia towards the longest cilium opens potassium ion channels within the inner hair cell, as the tectorial membrane makes contact
  • ionic interchange of potassium within the endolymph and inner hair ells causing cell depolarisation
  • inducing the opening of voltage-gated calcium channels releasing excitatory neurotransmitters (glutamate) onto the afferent nerve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the three scala/compartments of the cochlear?

A
  • scala vestibuli
  • scala tympani
  • scala media
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How can we categorise causes of hearing loss?

A
  • sensorinueral

- conductive

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

What is conductive hearing loss?

A
  • dissociation between air and bone conduction
    (bone is maintained, greater threshold required for air conduction)
  • middle or outer ear affected
  • hair cells are functional when stimulated within the inner ear
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is sensorineural hearing loss?

A
  • both air and bone conduction are affected similarly
  • problem with the inner ear of vestibulocochlear nerve problem
  • sound is unable to be effectively transduced to the auditory cortex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are possible causes of conductive hearing loss?

A 
outer ear:
- wax and foreign bodies
middle ear:
- otitis externa/media
- otosclerosis (stuck stapes)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are causes of sensorineural hearing loss?

A 
inner ear:
- presbycusis
- ototoxicity (loss of hair cells)
nerve:
- VIII nerve tumour (acoustic neuroma)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the main 2 tuning fork tests?

A
  • Rinne test

- Weber test

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

What are the 3 main inputs of the Vestibular system?

A
  • visual
  • proprioceptive
  • vestibular information
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the outputs of the Vestibular system?

A

reflexes to maintain a stable posture and stable gaze

  • ocular (maintains fixed image upon movement)
  • postural reflex (ensures individuals maintain composure)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What structure within the inner ear is anterior?

A

The cochlea concerned with auditory input.

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

What structure within the inner ear is posterior?

A

Labyrinth concerned with the vestibular system. The bony labyrinth resides within the petrous part of the temporal bone.

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

What is part of the vestibular organ?

A
  • utricle and saccule (in the vestibule), joined by a conduit.
  • Saccule is connected to the cochlea.
  • Three semi-circular canals (Anterior, posterior and lateral) in each ear.
  • with an ampulla on each side, connected to the utricle.
  • Canals contain endolymph fluid.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What angles are the semi-circular canals at?

A
  • the anterior and posterior semi-circular canal form a 90-degree angle
  • the anterior canal is 45 degrees to the front
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe the structure of vestibular hair cells?

A
  • kinocilium (largest cilium)

- stereocilia

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

What is the role of the stereocilia on the hair cells?

A
  • orientated to a particular side

- deflection induces cellular depolarisation in response to endolymph movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the otolith organs?

A
  • utricle

- saccule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the maculae made up of?

A
  • hair cells
  • gelatinous matrix (otolith crystals)
  • hair cells are horizontal in the utricle
  • hair cells are vertical in the saccule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is in the ampulla?

A
  • crista (hair cells)

- cupula which facilitates hair cell movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What does endolymph contain?

A

high concentration of K+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What should NOT be present in the semi-circular canals?

A

otoliths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Where does the vestibular nerve form nuclei?

A
  • Oculomotor nucleus
  • Trochlear nucleus
  • Medial longitudinal fasciculus
  • Abducens nucleus
  • Vestibular nuclei (Main generator of reflex.)
  • Vestibular ganglion
  • Vestibulospinal tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What does the vestibular nuclei have projections to?

A
  • spinal cord
  • nuclei of the extraocular muscles
  • cerebellum
  • centres of cardiovascular and respiratory control
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Where does the primary afferents of the vestibular nerve end?

A
  • vestibular nuclei

- cerebellum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Where are the main processing centres of the vestibular cortex?

A

in the parieto-insular vestibular cortex (parietal lobe)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is responsible for processing in the vestibular system?

A
  • main: vestibular nuclear complex

- adaptive: cerebellum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is the function of the vestibular system?

A
  • detect and inform about head movements
  • postural control
  • keep images fixed in the retina during head movements
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What happens with the stereocilia move towards the kinocilium?

A
  • depolarisation
  • increasing nerve discharge
  • excitation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What happens with the stereocilia move away from the kinocilium?

A
  • hyperpolarisation

- reduced nerve discharge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Describe the relationship between the hair cell potentials in the left and right ear?

A
  • antagonistic

- excitation and inhibition occur simultaneously at that specific velocity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What are the 2 different vestibular reflexes?

A
  • vestibulo-ocular reflex

- vestibulo-spinal reflex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What happens in the vestibulo-ocular reflex?

A
  • eye movement in opposite direction to head movement (same velocity and amplitude)
  • involves the vestibular nuclei and oculomotor nuclei
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Why does the vestibulo-ocular reflex occur?

A

to ensure images remain fixed in the retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What happens in the vestibulo-spinal reflex?

A
  • motor neurones to the neck and back muscles (medial tract)
  • postural control, compensatory body movement according to head position
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

How do you assess the vestibular system?

A
  • anamnesis (Hx)
  • posture and gait (posturography)
  • cerebellar function (CT and MRI)
  • eye movements
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What tests can be done to test the vestibular system?

A
  • caloric test
  • video head impulse test
  • vestibular evoked myogenic potential
  • rotational test
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What happens in a caloric test?

A
  • tests the semi-circular canals

- stimulates the inner ear with different temperature to identify how symmetrical the responses are)

47
Q

What happens in a Video head impulse test (vHIT)?

A

measures the vestibulo-ocular reflex

48
Q

What is Benign Paroxysmal Positional Vertigo (BPPV)?

A
  • peripheral vestibular disorder

- labyrinth and/or vestibulocochlear nerve

49
Q

How does Benign Paroxyxmal Positional Vertigo?

A

intermittant vertigo when standing up which is resolved when sitting down, the duration about 30 seconds

50
Q

How do you distinguish between BPPV and Meniere’s disease?

A

in BPPV vertigo episodes are around 30 seconds long

51
Q

What is the pathophysiology of BPPV?

A
  • otoliths from the utricle are detached from the maculae and dislodged into the semi-circular canals
  • otoliths stimulate a larger endolymph flow, head movement is processed by the brain as bigger and faster than actually perceived
  • otoliths settle int he posterior semi-circular canal (gravity)
  • posterior semi-circular canal has an impermeable barrier to trap otoliths
52
Q

What will stop BPPV?

A
  • continues util otolith crystal returns to the utricle with repositioning manoeuvres (epley, sermont)
53
Q

What is Meniere’s disease?

A
  • increased amount of endolymph liquid in the inner ear
  • degrades the membrane
  • recurrrent
54
Q

What characterises Meniere’s disease?

A

an episode of sudden onset vertigo

55
Q

How does Meniere’s disease present?

A
  • tinnitus

- episodes of vertigo

56
Q

What are other examples of peripheral vestibular disorders?

A
  • vestibular neuritis (acute)
  • unilateral/bilateral vestibular hypofunction
  • schwannoma vestibular tumour
57
Q

What is schwannoma vestibular disorder?

A
  • 8th nerve (vestibulocochlear) tumour

- progressive

58
Q

What do central vestibular disorders affect?

A

CNS (brainstem/cerebellum)

59
Q

What can cause central vestibular disorders?

A
  • stroke
  • MS
  • tumours
60
Q

What are possible differentials for dizziness?

A
  • heart disorders
  • presyncopal episodes
  • orthostatic hypotension
  • anaemia
  • hypoglycaemia
  • psychological
  • gait disorders
61
Q

What is the function of the outer ear?

A
  • capture sound
  • focus sound on the tympanic membrane
  • amplify frequencies by resonance in the canal
  • protects the ear from external threats
  • cilia - prevents external entrance
  • wax - covers inner ear, unfavourable pH for pathogens
62
Q

What is the function of the middle ear?

A

the amplify sound

63
Q

Describe the structure to the scala vestibuli and scala tympani?

A

bony structures with sodium-rich perilymph

64
Q

Describe the structure of the scala media?

A
  • membranous structure
  • potassium-rich perilymph
  • organ of corti
65
Q

What do vibrations of the basilar membrane trigger?

A
  • the movement of outer cell stereocilia
  • moving the tectorial membrane into contact with the inner hair cells
  • causing the opening of potassium ion channels
  • depolarisation of cell membrane and transmission of an electrical impulse via the auditory vestibular nerve to the ipsilateral cochlear nerve
66
Q

Describe the structure of the Organ of Corti?

A
  • contains inner and outer hair cells
  • inner hair cells are in ingle columns
  • outer hair cells are in columns of 3
  • OHCs are in continuous contact with the tectorial membrane (on vibrations, stereocilia movement facilitates the contact of the tectorial membrane with the IHCs
67
Q

What is the role of the inner hair cells?

A
  • transmit 95% of the afferent information of the auditory nerve
  • transduction of sound into nerve impulses
68
Q

What is the role of the outer hair cells?

A
  • modulate the sensitivity of the response
  • act as an active amplifier
  • stereocilia length can be altered to allow the tectorial membrane to be brought closer to the inner hair cells
69
Q

What impact the extent of the deflection of stereocilia and potassium ion channel opening?

A

amplitudes

70
Q

What happens in the depolarisation phase of the inner hair cells?

A

opens K+ channels (upwards phase)

71
Q

What happens in the repolarisation phase of the inner hair cells?

A

closes K+ channels

downwards phase

72
Q

Describe the auditory pathways?

A 
BRAINSTEM
- spiral ganglions from each cochlea project by the auditory vestibular nerve into the ipsilateral cochlear nuclei 
- auditory information crosses the superior olive level, and now all connections are bilateral
- inferior colliculus
THALAMUS
- medial geniculate body
CEREBRAL HEMISPHERE
- auditory cortex (temporal lobe)
73
Q

What is frequency/pitch?

A
  • Hz
  • cycles per second
  • perceived tone
74
Q

What is amplitude/loudness?

A
  • dB

- sound pressure

75
Q

What frequency is within the human range of hearing?

A

20-20,000Hz

76
Q

What amplitude/loudness is within the human range of hearing?

A

0-120 dB

77
Q

What decreases with age?

A

hearing acuity (especially at higher frequencies)

78
Q

What is the role of a cochlear implant?

A

replaces the function of the hair cells by receiving sound, analysing it and transforming it into electrical impulses to the auditory nerve

79
Q

What is required for a cochlear implant?

A

a functional auditory nerve

80
Q

What can be used if the auditory nerve is not functional?

A

a brainstem implant

81
Q

What is a brainstem implant?

A

electric signals from the cochlea can be relayed to a set of electrodes implanted directly into the brainstem

82
Q

When is a brainstem implant advised?

A

patients with bilateral auditory nerve damage (high risk)

83
Q

What do hearing aids do?

A

amplify sound (beyond hearing threshold of hearing loss)

84
Q

What does the type of hearing aid depend on?

A

type, degree and characteristic of the patient

85
Q

What are the possible treatments of hearing loss?

A
  • hearing aids
  • cochlear implants
  • brainstem implants
86
Q

What is mixed hearing loss?

A
  • both air and bone conduction is affected

- greater thresholds are required to discriminate a specific frequency

87
Q

What is the threshold for normal hearing?

A

0-20dB

88
Q

What is the threshold for mild hearing loss?

A

20-40dB

89
Q

What is the threshold for moderate hearing loss?

A

40-70dB

90
Q

What is the threshold for severe hearing loss?

A

70-90dB

91
Q

What is the threshold for profound hearing loss?

A

90+ dB

92
Q

What is otitis media?

A
  • inflammation of the middle ear

- associated with infection

93
Q

What is a characteristic of otitis media?

A

bubbles seen through the tympanic membrane

94
Q

What is presbycusis?

A

progressive hearing loss due to age

95
Q

What could affect cortical potentials?

A
  • neurological conditions

- processing problems

96
Q

Why is a tuning fork used?

A

to establish the presence or absence of a hearing loss with a significant conductive component

97
Q

What can the Rinne and Weber test do?

A

distinguish between conductive hearing loss and sensorineural hearing loss

98
Q

What is the Weber test?

A
  • hit tuning fork on knee or elbow
  • place base on the patients forehead
  • ask patient if it is louder in a particular ear
  • unilateral conductive: louder in deaf ear
  • unilateral sensorineural: louder in normal
99
Q

What is the Rinne test?

A
  • place base of tuning fork against the patients mastoid process
  • lift and place 1 cm from external auditory meatus
  • air louder than bone: normal
  • bone louder than air: conductive hearing loss
  • air louder than bone: sensorineural hearing loss
100
Q

What does the Rinne test do?

A

compares bone and air conduction

101
Q

Other than tuning forks, what tests can be done to assess hearing loss?

A
  • audiometry
  • central processing assessment
  • tympanometry
  • otoacoustic emission
  • electrocochelography
  • evoked potentials
102
Q

What does a Pure tone audiometry measure?

A

hearing acuity for variations in sound intensity and frequency

103
Q

What is an audiometry?

A

a device used to produce the sound of varying intensity and frequency

104
Q

What is an audiogram?

A
  • hearing thresholds are plotted to define if there is hearing loss or not
  • hearing loss: progressive increase in the hearing thresholds required to hear the sound at the specific frequency
105
Q

What is a Central Processing Assessment?

A

assessment of hearing abilities other than detection: sound localisation, filtered speech and speech in noise
(assesses sound discrimination and comprehension)

106
Q

What happens in a Tympanometry?

A

tests the condition of the middle ear and the mobility of the ear drum and ossicles by generating variations of air pressure in the ear canal

107
Q

What would cause a non-compliant tympanic membrane?

A
  • middle ear effusion
  • perforation of the tympanic membrane
  • pharyngomatic tube dysfunction
  • occluded ear canal
108
Q

What does Otoacoustic emissions (OAEs) test?

A
  • OAEs are produced by the outer hair cells as the expand and contract
  • none means the outer hair cells are NOT functional
109
Q

What test is part of the new-born hearing screening and hearing loss monitoring?

A

Otoacoustic emissions (OAEs)

110
Q

What happens in auditory evoked potentials electrochleography?

A
  • 0.2-4ms
  • electrical activity from the cochlea and the VIII nerve
  • evoked by clicks or tone burst
111
Q

What is done in an auditory brainstem response test?

A
  • 1.5-10ms
  • electrical activity from the VIII nerve and brainstem nuclei (evoked by clicks)
  • alterations in latency of waves can indicate the location of the deficit
112
Q

When is an auditory brainstem response test done?

A

in babies and children

113
Q

What is tested in a late response?

A

80-500+ms

  • activity from the primary auditoty and association cortex
  • evoked by tone burst and oddball paradigm

BRS YR2 (70 decks)

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