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
  • concha
  • 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
  • tympanic membrane
  • ossicles
  • tensor tympani
  • stapedius
  • oval window
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 of sound into nervous impulses
  • captures frequency and loudness of sound
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the function of the outer ear?

A
  • focuses sound on the tympanic membrane
  • modest amplification
  • protects ear from external threats
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the function of the middle ear?

A
  • mechanical amplification of sound
  • can reduce amplitude of sound via contraction of the tensor tympani and stapedius muscles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the inner ear innervated by?

A

Vestibulocochlear nerve (CN VIII)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
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
9
Q

What is the auditory pathway in the ear?

A
  • stapes vibrates the oval window
  • perilymph in the scala vestibuli vibrates
  • waves in the perilymph move around the cochlea
  • the waves move into the perilymph in the scala tympani
  • the wave reaches the end at the round window
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the auditory pathways to the brain?

A
  1. cochlea
  2. vestibulocochlear nerve
  3. dorsal or ventral cochlear nucleus
  4. inferior colliculus
  5. medial geniculate nucleus
  6. auditory cortex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the function of the inferior colliculus?

A

Localises sound so you know where it’s coming from

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

What is the pathway for signals in the dorsal cochlear nucleus?

A

Decussate to join the inferior colliculus

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

What is the pathway for signals from the ventral cochlear nucleus?

A
  • travels through superior olive on the same or opposite side
  • fibres travel to the inferior colliculus on the same side as the superior olive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why is it rare to have total hearing loss after a stroke?

A

All connections after the superior olive are bilateral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
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
16
Q

What are the three scala/compartments of the cochlea?

A
  • scala vestibuli
  • scala tympani
  • scala media
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the structure of the cochlea?

A

Spiral tunnel

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

Decribe the three scala

A
  • scala vestibuli and scala tympani = bony sturctures containing perilymph
  • scala media = membranous structure containing endolymph
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the difference between endolymph and perilymph?

A
  • perilymph = rich in Na+
  • endolymph = rich in K+
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Where is sound tranduced into a nervous signal?

A

Organ of corti, located in the scala media

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

What does the organ of corti contain?

A
  • basilar membrane
  • inner and outer hair cells
  • tectorial membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the mechanical properties of the base of the basilar membrane?

A
  • narrow
  • short and stiff hair cells
  • detects high frequencies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the mechanical properties of the apex of the basilar membrane?

A
  • wide
  • long and loose hair cells
  • detects low frequencies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How are hair cells arranged in the organ of corti?

A

Three rows of outer hair cells to one row of inner hair cells

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

What is the difference between the outer and inner hair cells?

A
  • outer = efferents, modulate sensitvity of the response to sound
  • inner = afferents, transduce sound into nerve signals, most important for hearing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Describe the process of mechanotransduction

A
  • vibration of the basilar membrane oscillates hair cells
  • stereoscilia sway with the same frequency as the basilar membrane
  • the oscillations towards the longest cilia change the structure of the membrane ion channels and cause changes in their permeability
  • K+ inlfux into hair cells leading to depolarisation
  • K+ channels close when stereocilia oscilate towards shortest cilia, leading to repolarisation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the longest cilia called?

A

Kinocilia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are stereocilia?

A
  • hairs on the hair cells cells which detect sound
  • located in the endolymph
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the primary auditory cortex and how is it arranged?

A
  • cortically processed sound
  • tonotopically organised like basilar membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the secondary auditory cortex?

A

Where association of sound occurs

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

Where are the auditory cortices located?

A

Temporal lobe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
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
33
Q

What is conductive hearing loss?

A
  • ear connot transmit sound to cochlea due to mechanical problem
  • middle or outer ear affected
  • hair cells are functional when stimulated within the inner ear
  • 10% of hearing loss, often reversible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is sensorineural hearing loss?

A
  • both air and bone conduction are affected similarly
  • problem with the inner ear or vestibulocochlear nerve
  • sound is unable to be effectively transduced to the auditory cortex
  • 90% of hearing loss, often irreversible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
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
36
Q

What are causes of sensorineural hearing loss?

A
  • drugs
  • Meniere’s disease
  • congenital infection
  • trauma
  • ageing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are the main 2 tuning fork tests?

A
  • Rinne’s test
  • Weber test
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the results for the Rinne’s test?

A
  • normal = air conduction > bone conduction
  • conductive HL = bone conduction > air conduction
  • sensorineural HL = normal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are the results for the Weber test?

A
  • normal = sound equal in both ears
  • conductive HL = sound louder in bad ear
  • sensorineural HL = sound louder in good ear
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the function of the vestibular system?

A
  • detect and inform about head movements
  • keep images fixed to the retina during head movements
  • balance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What are the main inputs of the Vestibular system?

A

Movement and gravity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What are the outputs of the Vestibular system?

A
  • ocular reflex (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
43
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
44
Q

Which nerve is involved in the vestibular system?

A

Vestibulocochlear nerve (CN VIII)

45
Q

What structure within the inner ear is posterior?

A
  • vestibular system labyrinth
  • contains bony, membranous and vestibular labyrinth
46
Q

Where does the bony labyrinth lie?

A

Cavities in the petrous temporal bone

47
Q

What is part of the vestibular organ?

A
  • vestibular labyrinth (utricle and saccule), joined by a conduit.
  • Saccule is connected to the cochlea.
  • Three semi-circular canals (Anterior, posterior and lateral) in each ear.
  • ampulla on each side, connected to the utricle.
  • Canals contain endolymph fluid.
48
Q

What angles are the semi-circular canals at?

A
  • the anterior and posterior semi-circular canal form a 90-degree angle
  • lateral canals are horizontal to the other canals
  • therfore they work in pairs
49
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
50
Q

What are the otolith organs?

A
  • utricle
  • saccule
51
Q

What is the function of the utricle?

A
  • detects changes in horizontal acceleration
  • changes head position during neck flexion and extension
52
Q

What is the function of the saccule?

A
  • detects changes in vertical acceleration
  • changes head position during lateral tilt
53
Q

How are cells arranged in the otolith organs?

A
  • located in the maculae
  • horizontal in the utricle
  • vertical in the saccule
54
Q

What is the maculae made up of?

A
  • hair cells
  • gelatinous matrix (otolith crystals)
  • otoliths on top
55
Q

What is in the ampulla?

A
  • crista (hair cells)
  • cupula which facilitates hair cell movement
56
Q

What does endolymph contain?

A

high concentration of K+

57
Q

How does endolymph in the semilunar canals move upon rotation?

A
  • moves in the opposite direction to rotation
  • exerts force on the cupula, causing it to fill and bend cilia
  • will either excite or inhibt cilia depending on the direction of rotation (towards or away from the cilia)
58
Q

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

A

otoliths

59
Q

Where does the vestibular nerve form nuclei?

A
  • Oculomotor nucleus
  • Medial longitudinal fasciculus
  • Abducens nucleus
  • Vestibular nuclei (Main generator of reflex.)
  • Vestibular ganglion
  • Vestibulospinal tract
60
Q

What does the vestibular nuclei have projections to?

A
  • spinal cord
  • nuclei of the extraocular muscles
  • cerebellum
  • centres of cardiovascular and respiratory control
61
Q

Where do the primary afferents of the vestibular nerve end?

A

vestibular nuclei in the brainstem

62
Q

Where are the main processing centres of the vestibular cortex?

A

in the parieto-insular vestibular cortex (parietal lobe)

63
Q

What is responsible for processing in the vestibular system?

A
  • main: vestibular nuclear complex
  • adaptive: cerebellum
64
Q

What happens with the stereocilia move towards the kinocilium?

A
  • depolarisation
  • increasing nerve discharge
  • excitation
65
Q

What happens with the stereocilia move away from the kinocilium?

A
  • hyperpolarisation
  • reduced nerve discharge
66
Q

What are the 2 different vestibular reflexes?

A
  • vestibulo-ocular reflex
  • vestibulo-spinal reflex
67
Q

What happens in the vestibulo-ocular reflex?

A
  • eye movement in opposite direction to head movement (same velocity and amplitude)
  • impulse stimulates ipsilateral vestibular nucleus then the contralateral abducens nucleus and then the ipsilateral oculomotor nucleus
  • contracts ipsilateral medial rectus and contralateral lateral rectus
  • keeps images fixed on the retina
68
Q

How do acute unilateral vestibular disorders usually present?

A
  • imbalance
  • dizziness
  • vertigo
  • nausea
69
Q

How do slow unilateral and both bilateral vestibular disorders present?

A
  • imbalance and nausea
  • no vertigo
70
Q

How can vestibular disorders be characterised by location?

A
  • peripheral (affects vestibular organ and/or vestibulocochlear nerve)
  • central (affects CNS, specifically brainstem/cerebellum)
71
Q

What are some examples of peripheral vestibular disorders?

A
  • Vestibular neuritis
  • Benign Paroxysmal Positional Vertigo (BPPV)
  • Meniere’s disease
72
Q

What are some examples of central vestibular disorders?

A
  • stroke
  • multiple sclerosis
  • tumours
73
Q

What are the red flags for vestibular disorders?

A
  • Headache
  • Gait problems
  • Hyper-acute onset
  • Hearing loss
  • Prolonged symptoms (>4 days)
74
Q

How do you assess the vestibular system?

A

Assess eyes, ears and legs

75
Q

What is the clinical exam for acute dizziness?

A

HINTS exam

76
Q

What does the HINTS exam assess?

A
  • Head Impulse test (horizontal rotation VOR)
  • Nystagmus (vestibular vs brainstem)
  • Test of Skew deviation (vertical misalignment)
77
Q

How does Benign Paroxyxmal Positional Vertigo present?

A

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

78
Q

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

A

in BPPV vertigo episodes are around 30 seconds long

79
Q

What is the pathophysiology of BPPV?

A

Dislodging of carbonate crystals in the semi circular canals

80
Q

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

A

amplitudes

81
Q

What is frequency/pitch?

A
  • Hz
  • cycles per second
  • perceived tone
82
Q

What is amplitude/loudness?

A
  • dB
  • sound pressure
83
Q

What frequency is within the human range of hearing?

A

20-20,000Hz

84
Q

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

A

0-120 dB

85
Q

What decreases with age?

A

hearing acuity (especially at higher frequencies)

86
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

87
Q

What is required for a cochlear implant?

A

a functional auditory nerve

88
Q

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

A

a brainstem implant

89
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

90
Q

When is a brainstem implant advised?

A

patients with bilateral auditory nerve damage (high risk)

91
Q

What do hearing aids do?

A

amplify sound (beyond hearing threshold of hearing loss)

92
Q

What does the type of hearing aid depend on?

A

type, degree and characteristic of hearing loss

93
Q

What are the possible treatments of hearing loss?

A
  • hearing aids
  • cochlear implants
  • brainstem implants
  • underlying cause
94
Q

What is the threshold for normal hearing?

A

0-20dB

95
Q

What is the threshold for mild hearing loss?

A

20-40dB

96
Q

What is the threshold for moderate hearing loss?

A

40-70dB

97
Q

What is the threshold for severe hearing loss?

A

70-90dB

98
Q

What is the threshold for profound hearing loss?

A

90+ dB

99
Q

What is otitis media?

A
  • inflammation of the middle ear
  • associated with infection
100
Q

What is a characteristic of otitis media?

A

bubbles seen through the tympanic membrane

101
Q

What is presbycusis?

A

progressive hearing loss due to age

102
Q

What could affect cortical potentials?

A
  • neurological conditions
  • processing problems
103
Q

Why is a tuning fork used?

A

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

104
Q

What can the Rinne and Weber test do?

A

distinguish between conductive hearing loss and sensorineural hearing loss

105
Q

What does the Rinne test do?

A

compares bone and air conduction

106
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
107
Q

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

A

Otoacoustic emissions (OAEs)

108
Q

What is an audiogram?

A

where the hearing thresholds are plotted to define if there is a hearing loss or not

109
Q

What is the difference between dizziness and vertigo?

A
  • dizziness = room is still, you feel unstable
  • vertigo = room is spinning, you feel stable

BRS YR2 (67 decks)

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