Quiz 2 (Inner Ear) Flashcards
(110 cards)
1
Q
bring about transduction mechanism and allows nerves to integrate the signal
A
ihc
2
Q
which ion channels are disrupted in connexins
A
potassium
3
Q
what is inner ear homeostasis
A
chemical equilibrium of the IE fluids for proper functions
4
Q
inner ear functions include
A
hair cell fxn
regulation of extracellular endo and perilymph
conduction of nerve impulses
5
Q
major ions
A
sodium
potassium
chloride
calcium
6
Q
Ion movement is controlled by genes, channels, and water
A
true
7
Q
help maximize sensitivity of hair cells
metabolic support behind hearing
A
endo and perilymph
8
Q
describe the inner ear endocochlear potential
A
intracellular potential is -80mv and high potassium in the endolymph creates + 80mV EP so this creates a 160mV differential potential
9
Q
what is the differential potential needed for
A
to cause hair cell shearing and electrical signaling
10
Q
EP in the vestib system is only
A
5-10mV
11
Q
EP is higher where
A
in cochlea than vestibular system
at basilar end than apical
12
Q
what happens after shearing of stereocilia
A
stereocilia are displaced by motion of IHC or shearing of OHC
both rush potassium into the cell
13
Q
what happens when peri and endo fluids are the same
A
causes reduced transduction resulting in Meniere’s disease (mixing of both)
14
Q
Stria vascularis generates
A
potassium and has connexin gap junctions that facilitate potassium transport
15
Q
The junctions are tight and contribute to the endocochlear potential because
A
they limit intracellular leakage of ions
16
Q
gap junction
A
for potassium
17
Q
tight juction
A
for blood/vascular cells
18
Q
why is stria susceptible to many genetic disorders
A
becuase it is controlled by connexin gap junctions that faciliate K+ transport
19
Q
cochlear disorders that disrupt stria, channels, transporters, gap or tigh junctions reduce
A
EP and result in HL
20
Q
A gap junction or nexus is a specialized intercellular connection that
A
directly connects two cells allowing molecules and ions to pass freely between the two
21
Q
what are aquaporins
A
proteins that regulate the flow of water
play a role in water homeostasis
blood-brain barriers and blood-labyrinthine barrier
an cause viral infections if damaged
22
Q
Increased K+ transport in the endolymph or increased endolymph production
A
endolymphatic hydrops (too much endolymph - Meneire’s - progressive fluctuating snhl)
23
Q
Decreased K+ transport in the endolymph or decreased endolymph production
A
endolymphatic xerosis (connexin, JLNS - permanent snhl)
24
Q
causes the most genetic HL in humans
A
endolymphatic xerosis
25
abnormal connexin gap junctions, over 50% nonsyndromic HL
connexin 26
26
protein that makes K+ channels, responsible for reduced endolymph in HL with JLNS syndrome
KCNE1 & KCNQ1
27
which condition are KCNE1 KCNQ1?
jlns
28
DFNA
Deafness, Nonsyndromic, Autosomal Dominant
29
DFNB
Deafness, Nonsyndromic,Neurosensory, Autosomal Recessive
30
DFNX
Nonsyndromic deafness, X-linked
31
temporary disorders of ion homeostasis
sudden hl onset
diuretic ototoxicity
autoimmune labyrinthitis
Meniere's disease
32
what indicates HL as homeostatic issue and not hair cells
these disorders manifest temporary hearing loss and recovery indicates that the damage is not to the hair cells but to the ion homeostatic process
33
symptoms of cochlear disorders
constant or fluctuating HL
almost always SNHL (can have mixed)
speech perception issues
loudness recruitment
aural fullness
tinnitus
conditions paired with psychological issues
34
hyperacusis
hurts when sound is too loud
35
misophonia
intense emotional feeling towards specific sounds
36
noise sensitivity
reaction to discomforting sounds
doesn't have to be loud
37
phonophobia
fear of sound
makes tinnitus worse
38
common causes of SNHL
presbycusis
exposure to toxic levels of noise (noise induced HL
39
what causes inner ear infections
mostly viruses
some bacterial (meningitis)
40
two kinds of viruses known
RNA virus (covid & flu)
DNA
41
what is RNA virus
contain rna in their genome, mutate quickly due to lack of proofreading making it difficult to treat
42
what is dna virus
these contain dna in their genome and are more stable
smallpox, herpes, chickenpox
43
what is an example of rna virus
rubella & paramyxovirus
44
what is rubella virus
rna virus
responsible for german measles, effects A.S. if contracted by mom in first part of 2nd trimester when it is developing
45
rubella virus leads to
congenital HL, cataracts, cardiovascular cataracts, maybe intellectual disability
46
what is paramyxovirus
rna virus
responsible for mumps & causes male infertility
47
paramyxovirus leads to
parotid gland inflammation causes acquired unilateral SNHL
48
example of DNA virus
cytomegalovirus CMV
49
what is CMV
herpes family, most common viral disease in humans
50-80% US people have the antibodies by their 40’s
Decreased life expectancy, large liver and spleen, a “blueberry muffin” rash, and decreased immunity to fight off other diseases
Has the MOST GENES of any virus
50
most common newborn virus
CMV
51
if mom has CMV, what should they do
not breastfeed for first 3 weeks to avoidpassing it on
52
audio findings of cmv
progressive profound permanent SNHL by 3-5 yrs
kids are ci candidates
53
why are cmv newborns hearing unetected
it can be late onset or we are not screening for it
54
problems cmv causes
neurological deficits, blindness, ID, and cardiovascular problems
55
how is cmv diagnosied
GOLD STANDARD IS URINE POLYMERASE CHAIN DNA
can also do histological exam of inclusion bodies in saliva and lungs
CT to show intracranial calcification
56
are inclusion bodies specifc to cmv
NO shown in many viruses
57
Viral infections are destructive and causes
Damage to the basal turn of the cochlea (high freq SNHL)
Hair cell damage
Stria vascularis atrophy
Tectorial membrane rolls up
Reissner’s membrane collapses
58
high frequencies and pure tones cause more damage than low frequencies and WBN
true
59
what is meningitis
inflammation of the meninges of the brain and spinal cordwha
60
etiology of meningitis
virus & bacteria
61
primary meningitis
originates in meninges
62
secondary meningitis
originates outside of the meninges and travels to them (ex: cholesteatoma or OME → mastoiditis)
63
signs and symptoms of meningitis
Initially: high fever, neck stiffness, malaise, nausea, vomiting
Untreated: blindness, paralysis, hearing loss/deafness (causes acquired SNHL), and vertigo/off balance
64
treatment for meningitis
antibiotics (do a spinal tap to see which one to give), mastoidectomy (if related to the ME), amplification/CI (ensure cochlea isn't overgrown with bone, and that there is enough space to put a CI)
65
what is a perilymphatic fistula
ME and IE have a connection to each other when normally they are self contained at either or both oval and round windows
66
etiologies of perilym fistula
idiopathic
feeling ear "pop" after heavy lifting
randomly found during Meniere's surgery or stapedectomy
67
symptoms of perilym fistula
vertigo without HL
HL without vertigo
symptoms that cannot be determined from Meniere’s (SNHL, vertigo, tinnitus, aural fullness)
not episodic vertigo but disequilibrium with miscellaneous symptoms
68
how to determine perilym fistula
presentation of complex symptoms
case history, symptoms they present with and can have different presentations of symptoms
high index of clinical suspicion
dix hallpike to see nystagmus or vertigo
69
treatment of fistula
no heavy lifting
me exploration
surgery to seal leak
70
what can happen after repair of fistula
preserve hearing that is left
resolve balance issues
improve tinnitus
71
what is noise induced hearing loss (NIHL)
Hearing loss as a result of harmful noise exposure (dose/level and duration/time dependent)
72
dose
leveld
73
duration
time
74
has most weight for human hearing
.5-8kHz
75
noise notch bw 3-6000 Hz (peak bw 4 & 6kHz)
due to cochlea geometry & blood supply
NIHL
76
what hearing sensitivity change will we see with NIHL
max damage is ½ an octave above stimulating frequency (ex: stimulating at 1 kHz but HL at 1.5 kHz)
77
temporary threshold shift
reversible shift that can resolve 15 mins after exposure or persists up to 14 hours
produced by initial noise exposure
dull or muffled sound quality (at end of work shift or loud concert)
even if TTS shift comes back to baseline, can result in hidden hearing loss where there is no change in hearing but there is residual issues
78
permenant threshold shift (PTS)
persistent change in sensitivity, persists after approx. 14 hrs
noise is bad and long enough that it doesn’t go back to baseline
if at 125 dB it is permanent
79
Both accompanied by tinnitus (can be a useful warning if you get it after a temporary shift)
true
80
Initial noise exposure produces TTS, but a daily dose of noise exposure that DOESN'T cause TTS WILL NOT cause PTS
true
81
effects on me and noise
rare
82
™ perf after blast =
possible concussion
83
, >/= 165 dB SPL can cause
™ perf,
84
>/= 190 dB SPL can cause
ossicular chain injury
85
inner ear and noise
can result in tinnitus and oHC damage
stereocilia first lose stiffness (TTS) and after repeated damage becomes permanent (PTS)
86
more intense & prolonged loud sounds =
greater degree of hair cell loss
87
can noise cause NIHL vestib issues
doubtful BUT ACOUSTIC TRAUMA CAN
88
COCHLEA MORE SUSCEPTIBLE TO NOISE LOSS, ME depending on loudness level
TRUE
89
how to diagnose NIHL
clinical hx & audio data showing SNHL
medical exam to rule out other causes of HL
90
audio configuration
usually symmetrical but asymmetries >/= 15 dB HL not uncommon(usually in HF - 3 to 6 kHz, with firearm use)
profound SNHL rare, LF thresholds better than 40 dB HL, HF thresholds rarely better than 75 dB HL
presbycusis can flatten noise notch
91
notch flattens when noise induced meets presbycusis
true
92
management of NIHL
no effective treatment
PREVENTION IS BEST MANAGEMENT
use of appropriate amplification w/ permanent HL
use of antioxidants & other chemicals that protect against NIHL (being investigated)
93
what is acoustic trauma
form of NIHL that is a sudden, permanent HL as a result of a single event (NO TTS)
Caused by impulse noise of 165-190 dB SPL that causes direct mechanical damage to the cochlea (can also rupture the eardrum)
94
Impulse noise over 140dB SPL can also cause PTS immediately
true
95
sound intensity bw 165 to 190 dB SPL
ruptures or produces ™ hemorrhage
disrupt/fracture ossicular chain
96
otoscopy on acoustic trauma
tm perf or hemorrhage
97
audio results for acoustic trauma
similar to NIHL
noise notch at 3 & 6 kHz
HF sloping configuration
flat configuration (more common)
mixed HL = if ossicular disarticulation has occurred
98
tymps of acoustic trauma
type Ad if ossicular disarticulation
99
which parameter is abnormal in type Ad?
static admittance
100
perf tymp?
type b with high ECV
101
type b but not high volume?
peak pressure is not measured
admittance is not measured
just volume is measured
102
art in acoustic trauma
absent if ossicular disruption
103
HL may improve over 4-6 mo period if from acoustic trauma
true
104
surgery could be used to repair ™ and ossicles if they are damaged in acoustic trauma
true
105
why can we not replicate hair cells?
they are in G0 phase that stops the cell cycle
when you take it out it messes with the cycle and causes tumors throughout the body
*have to find a way to counterbalance this before regenerating hair cells
106
what are blast injuries
type of acoustic trauma
caused by indirect impact from pressure wave created from an explosion
107
blast injuries are more dangerous why
when bomb goes off, pressure wave causes damage
so much heat and pressure when it goes off
108
damage as result of blast injury
™ perf, ossicular disarticulation, tinnitus, otalgia, HL and/or vertigo
109
why is otologic usually initially missed
this is because high priority is for life threatening injuries
110
