EXAM 2 Flashcards
(238 cards)
horizontal canals cause vertigo sx when you move your head
side to side
a VOR less than ___ indicates the eyes are moving slower than the head
1
vestibular sx often produce a ____output to correct
motor
vestibular anatomy is broken into 3 main categories, what are they
peripheral sensory apparatus (inner ear)
central processing center
motor ouput sx
what is peripheral sensory apparaus
inner ear
Provides sensory input about BOTH angular and linear acceleration
Orients the head with respect to gravity
what is central processing center
Somatosensory and visual cues
Cerebellum
Reticular formation, cortex
what is motor output sx
Generates compensatory eye movements for gaze stability
Body movements for postural stability with locomotion (through vestibulospinal tract
explain how your body detects movement in the inner ear
Canals detect head movement (ant, post and lateral)hair cells are sensory organs, when endolymph fluid moves it effects hair cells
what makes up the labyrinth (inner ear)
Contains 5 sensory organs: 3 semicircular canals Anterior Posterior Lateral
2 otolith organs
Utricle
Saccule
Hair cells-motion sensors
each ear canal is ___to the other
perpendicular
explain the “push pull” reaction of the inner ear cannals
bc of the positioning of the canals, turning head 1 way would excite 1 canal but inhibit it’s opponent
information from the canals is used to
stabalize vision
Macula of the utricle is oriented in the ___plane
horizontal
macula of the sacule is oriented in the ___ plane
vertical
information from the otolith organs is used for
balance control
both the sacule and urtricle have
macula (hair cells and crystals here)
2 central processors (vestibular)
vestibular nuclei
cerebellum
explain how firing rate of nuclei can make a person feel dizzy
Both vestibular nuclei (each side) will fire at a certain frequency. For example, turning head to right, the right vestibular nuclei has higher frequency of firing (how your brain knows you have turned to the right) eyes and postural muscles will fall in line with what the brain tells them.
But, if one side of the nuclei is not firing as much, the other is firing all the time and the brain thinks the person is always turning head to the side it’s firing, so the eyes and postural muscles will try to fall in line (even though it’s not right) = dizziness
your eyes remain stationary during walking bc of your
VOR
deficit of the VOR results in
osscilopsia
the VOR is regulated by
Regulated by afferent input from semicircular canals
VOR is induced by ___ speed
FAST
nystagmus indicates
1 vestibular sx is more active than the other
when the vestibular nuclei aren’t equal
nystagmus is classified/named by
the direction of quick beat