Block 3 Flashcards
1
Q
what structure of the ear contains hair cells
A
organ of corti
2
Q
when the organ of corti is wound down, the apex contains __ frequency while the base contains __ frequency
(high or low frequency)
A
apex= high frequency
base= low frequency
3
Q
what is presbyacusis
A
lose of high frequency sound before low frequency
4
Q
what hair cells are connected to the tectorial membrane
A
outer
5
Q
what hair cells are connected to the tectorial membrane
A
outer
6
Q
what is the tall hair cell in which the other hair cells bend towards or away from
A
kinocilium
7
Q
when hair cell bend towards the kinocilium, there is depolarization or hyperpolarization and an increase or decrease in the rate of firing
A
towards= depolarization, more firing
8
Q
when hair cell bend away the kinocilium, there is depolarization or hyperpolarization and an increase or decrease in the rate of firing
A
away= hyperpolarization, decrease
9
Q
what is used as the depolarizing signal as hair cells bend towards the kinocilium
A
K+ influx
10
Q
what is the function of inner hair cells
A
transform wave energy (“do the hearing”)
11
Q
what is the function of outer hair cells
A
dampen loudness by stretching in response to signal
12
Q
what are the contents of endolymph
A
high K+
low Na+
low Ca2+
high positive amino acids
13
Q
what are the contents of perilymph
A
high Na+
14
Q
what is the value of the endocochlear potential
A
150mV
15
Q
the ventral acoustic striata is also known as what
A
trapezoid body
16
Q
the spiral ganglion contains what class of cells
A
bipolar
17
Q
the primary auditory cortex is composed of Broadman areas __
A
41 and 42
18
Q
a lesion to Wernicke’s area results in __ aphasia with symptoms of
A
receptive
poor comprehension of speech, speak fluently but in “word salad”
19
Q
interaural differences in __ and __ are used to determine lateral input direction (angle)
A
level (sound from the right is louder on the right than the left)
time (sound from the right reaches the right ear sooner than the left)
20
Q
if the frequency for sound localization is >1600Hz, this indicates interaural level or time difference
A
level
21
Q
if the frequency for sound localization is <800Hz, this indicates interaural level or time difference
A
time
22
Q
what brain structure is important for localization of sound
A
superior olivary complex
23
Q
what is needed for coincidence detectors to fire for sound localization
A
signal from left and right ear to line up at the same time on a leading neuron
24
Q
the tensor tympani muscle which tightens the tympanic membrane is innervated by what nerve
A
trigeminal
25
the stapedius which prevents excess stapes movement is innervated by what nerve
facial
26
what is tinnitus sometimes caused by, although it is generally idiopathic
lack of loudness dampening by middle ear muscles
27
what is the mechanism in which outer hair cells dampen sound
movement of the basement membrane deforms outer hair cell stereocilia against the tectorial membrane. this causes K+ channels to open, outer hair cell motor proteins to shrink the cell, pulling down on the tympanic membrane and ultimately dampening the sound
28
most feedback efferent go to outer hair cells from the ___
superior olivary nucleus
29
conduction hearing loss is due to an issue at what location
before the cochlea
30
what are the 3 main causes of conduction hearing loss
wax
infection
cholesteatoma (skin cyst in middle ear)
31
sensorineural hearing loss is due to an issue at what location
past or at the cochlea
32
what are the 4 main causes of sensorineural hearing loss
-infection (MMR, CMV)
-drugs (NSAIDS, streptomycin, quinine, gentamycin)
-presbyacusis (esp. in elderly)
-vestibular schwannoma tumor
33
what are the 3 main drug classes that are ototoxic
salicylates
NSAIDS
antibiotics (aminoglycosides)
34
what type of medication leads to reversible ototoxic effects? irreversible?
reversible- salicylates
irreversible- antibiotics (aminoglycosides)
35
what is the process of the Weber test for conduction and sensorineural hearing loss
a 512 Hz tuning fork is placed on the patient's forehead
if the sound localizes (is louder on one side), patient has either ipsilateral conductive hearing loss of contralateral sensorineural hearing loss
36
what is the process of the Rinne test for conduction and sensorineural hearing loss
a tuning fork is placed on the mastoid behind the patients ear until sound is no longer heard. the fork is then placed at the side of the patient's ear and the sound should once again be heard
if no sound is heard, the test is negative
37
what is considered a normal positive test for the Rinne test
it indicates the ear is normal, as air conductance should be longer than bone conductance
38
39
what is the function of speech audiometry
measures the percentage of words correctly interpreted as a function of the intensity of presentation and indicates the usefulness of hearing
40
how does brainstem auditory evoked response for testing conduction and sensorineural hearing loss work
using an EEG, scalp electrodes measure response along the entire auditory path in response to sound stimuli
41
how does otoacoustic emission for testing conduction and sensorineural hearing loss work
microphones are fitted into the ear canal and are used to measure response to auditory stimulation
42
acute otitis media is usually caused by __ and presents with __ and __
viral, sometimes bacteria
earache and fever
43
serous otitis media is caused by __ and presents with __
altered eustachian tube function or viral/bacterial infection
conductive hearing impairment
44
chronic suppurative otitis media is caused by __ and presents with __
perforation in the tympanic membrane
otorrhea (pus drainage out of ear)
45
with presbyacusis, is hearing loss ipsilateral or bilateral, symmetric or asymmetric
bilateral symmetric
46
with presbyacusis, does high or low frequency tone go first
high
47
what is otosclerosis
abnormal bone growth in or near the middle ear, causing the stapes to become fixed in the oval window
48
what are the symptoms of otosclerosis
conduction hearing loss then sensorineural hearing loss
49
what is Meniere syndrome
disorder of the inner ear affecting the auditory and vestibular systems (the entire labyrinth)
50
what are the symptoms of Meniere syndrome
deafness
sensation of profound fullness in the ears
attacks of vertigo
sometimes nystagmus
51
what hearing loss do you get with Meniere syndrome
loss of low frequency range
52
what is the cause of Meniere syndrome
excess endolymph buildup (endolymphatic hydrops)
53
what is the treatment for Meniere syndrome
antihistamines
54
what are the symptoms of vestibular schwannoma
CN 8
unilateral hearing loss
tinnitus
vertigo
CN 7
pain in facial muscles which may become paralyzed
55
what is vestibular schwannoma
benign tumor that affects cranial nerve 8
56
the ear canals, ampullae, and maculae are filled with endolymph or perilymph
endolymph
57
when there is movement towards the kinocilium, there is depolarization and release of __
glutamate
58
cristae respond to what type of motion
rotational movement
59
cristae are made up of what 2 structures
utricle and saccule
60
the utricle deals with what type of motion
the saccule deals with what type of motion
utricle= linear acceleration/deceleration
saccule= up/down
61
maculae of the saccule respond to what and detect what
gravitational pull
linear acceleration/deceleration and head tilt forward and backward
62
vestibular ganglia (Scarpa's) fibers from the vestibular portion of CN VIII project where
lateral, medial, superior, and inferior vestibular nuclei in the caudal pons, rostral medulla, and caudal medulla
63
a disorder of the craniocervical junction causes what type of nystagmus
downbeat
64
with an upbeat nystagmus- large amplitude, this means there is a lesion where
anterior vermis
65
with an upbeat nystagmus- small amplitude, this means there is a lesion where
medulla
66
torsional nystagmus results due to a lesion where
anterior and posterior semicircular canals on the same side (or also with lateral medullary syndrome)
67
pendular nystagmus occurs due to dysfunction where
brainstem or cerebellum
68
gaze evoked nystagmus occurs due to what
an attempt to maintain extreme eye position
69
what is benign paroxysmal positional vertigo (BPPV)
brief episodes of vertigo usually related to changes in positions, often accompanied by horizonto-rotary nystagmus
70
how is benign paroxysmal positional vertigo (BPPV) differentiable from Meniere's disease
there is no hearing loss or tinnitus in BPPV
71
can symptoms of central or peripheral nystagmus be changed with head movement
peripheral
72
nystagmus and vertigo occur when the affected or unaffected side is turned downward in the Hallpike-Dix test with benign paroxysmal positional vertigo (BPPV)
affected
73
hyperventilation induced nystagmus occurs in __% of patients with __
92
vestibular schwannoma
74
vestibular neuritis (neuronitis) typically presents with __ following __
vertigo
URI
75
with caloric testing, cold water stimulates the head to turn to the same or opposite side
opposite
COWS
cold opposite warm same
76
with nystagmus, the slow response is due to __ while the fast response is due to __
slow= vestibulo-ocular reflex (VOR)
fast= nystagmus- PTO response
77
with caloric testing, cold water stimulates nystagmus in the same or opposite direction
opposite
COWS
cold opposite warm same
78
what will the nystagmus response be in someone who is unconscious but has an intact brainstem
slow drift due to vestibulo-ocular reflex but no fast drift
cold water= same side
warm water= opposite side
79
with an MLF lesion, cold water stimulates the head to turn __
cold= opposite
warm= same
80
81
82
are rods or cones very sensitive to light
rods
83
do rods or cones loss cause night blindness
rods
84
are rods or cones in the fovea
cones
85
are there more rods or cones in the retina
20x more rods
86
do rods or cones confer achromatic vision
rods
87
does loss of cones or rods cause legal blindness
cones
88
do rods or cones have high visual acuity
cones
89
do rods or cones have a fast response to light
cones
90
what are the characteristics of retinitis pigmentosa
dying pigment epithelium is release leading to clumps of melanin
nyctalopia (night blindness)
91
what is the difference between wet vs dry macular degeneration
wet- results in blood leakage
dry- damage to retinal pigment epithelium
92
what is seen in fundoscopy of someone with hypertension
copper color vessels then silver wiring vessels
93
what causes papilledema
swollen optic disc caused by increased ICP
94
what is the difference between near and far sighted
near- difficulty with far objects
far- difficulty with near objects
95
which lens, concave or convex, converges light
which diverges light
convex converges
concave diverges
96
what is amaurosis fugax
loss of vision in one eye
97
prednisone may cause blindness due to what effect of the drug
increases ocular pressure
98
what causes low-tension/normal tension glaucoma
poor blood flow to the optic nerve or "fragile" optic nerve fibers
99
how is signaling different in vision compared to typical signaling
hyperpolarization is the on signal
100
what is achromatopsia
damage to V4 causes an inability to perceive color
101
what is Balint's syndrome caused by
lesion to the dorsal parietal lobe (how and where of vision)
102
what are 3 symptoms of Balint's syndrome
optic ataxia (deficit in reaching for objects)
ocular apraxia (deficit in visual scanning)
simultanagnosia (can't perceive two objects simultaneously)
103
the FFA of the inferotemporal region recognizes __
the PPA of the inferotemporal region recognizes __
the EBA of the inferotemporal region recognizes __
FFA= face
PPA= place
EBA= body
104
what is prosopagnosia
face blindness
105
what is Anton's syndrome
denial of cortical blindness
106
visual anosognosia is most commonly encountered in patients with ___ lesions
bilateral occipital lobe
107
hemispatial neglect is usually due to lesions involving non-dominant __ cortex
right parietal
108
what is the main blood supply to the lateral geniculate body
anterior choroidal artery
109
what is the blood supply of the macular area of the primary visual cortex
posterior and middle cerebral artery
110
what is anisocoria
unequal pupil size in the 2 eyes
111
what 2 muscles control the size of the iris for the pupillary reflex
radial/dilator pupillae
circular/sphincter pupillae
112
the radial (dilator) muscle is under the control or sympathetic or parasympathetic control
sympathetic
113
what levels of the cell column are involved in pupillary dilation
T1-T4
114
levator palpebrae superioris is under the control of __ while the superior tarsal is under the control of __
levator palpebrae superioris= CN III
superior tarsal= sympathetics
115
if unequal pupils react normally to light but the anisocoria is greatest in the dark, the smaller pupil is normal or abnormal
abnormal (the common cause of this is Horners syndrome)
116
if unequal pupils react abnormally to light and the anisocoria is greatest in the light, the smaller pupil is normal or abnormal
normal
117
edinger westphal nucleus is used for the direct or consensual reflex
direct (ipsilateral)
118
contralateral edinger westphal nucleus projects to the posterior commissure for the direct or consensual reflex
consensual
119
pupillary constriction is elicited by the action of what neurotransmitter on what receptor type
ACh at M3 receptors
120
the afferent limb of the pupillary reflex (direct and consensual) is caused by CN __ while the efferent limb is caused by CN __
afferent= 2
efferent= 3
121
Adie's pupil is due to a problem with what
ciliary ganglion
122
what is the main characteristic of Adie's pupil
slow accommodation to light
123
what is smooth pursuit eye movement
foveal tracking of a small moving object opposite of the direction of vestibular ocular reflex
*maintains gaze on a stationary object
124
the corneal reflex tests the integrity of what cranial nerves
sensory of CN V
motor of VII
