23 JULY 2019 Flashcards
there are two divisions of fx of the vestibular system:
physically
visually
the vestibular system’s job is to
keep you steady in the world
the vestibular system contributes to
maintenance of balance and equilibrium
list of fx of the vestibular system?
- head movement
- position related to gravity - gaze stabilization
- postural adjustments
- autonomic fx & consciousness
all consciousness comes from the
cerebral cortex
everything that goes to the cerebral cortex pass through the
thalamus
teh vestibular apparatus includes five stsrcutures:
- semiciruclar canals
- vestibulocochlear N
- utricle
- saccule
- cochlea
how many semicircular canals are there?
three sets with two each so 6 total
five things to know about the semicircular canals?
- 3 per side
- hair cells in fluid
- determines baseline activity
- deplorazation rise/ falls
- paired activity
when you turn your head AP does what to what ears?
the side you are turning to INCREASES
the side you are turning away from DECREASE
acceleration means you
get more APs
deceleration means you get
less APs
so you when you turn your head which accelerates which decelerates
the side you are turning toward ACCELERATES
the side you are turning away from DECELERATES
the “seaweed” if what
the hair cells
what is the fx of the hair cells as seaweed
tells movement
seaweed floats in what
fluid
what do you find at semicircular
ampulla
what does baseline activity mean
that the hair cells always send the signals
paired activity means
that there are 3 semicircular canals that work together
semicircular canals are
angular movement
otolithic organ contains what
- utricle
2. saccule
utricle tells us
horizontal movement
saccule tells us
vertical movement
otoconia are
ear crystals
fx of the otoconia are
move hairs “seaweed”
what moves what with the otoconia and hair cells?
the hair cells move the otoconia
otoconia allow what
your body to feel the pull of gravity
vestibular nuclei is apart of what CN / pathway
CN VIII: VESTIBULAR DIVISION PATHWAY
where is CN VIII tract/ pathway located
the pons-medulla junction
during eye tracking what is the nystagmus part?
the really fast reset
during eye tracking what is the reflex part?
the tracking
difference between the optokinetic
reflex and nystagmus
nystagmus = just fast reset reflex = tracking
list five locations that can have disorders occur there in the vestibular system
- peripheral receptors
- cranial nerve 8
3 brainstem nuclei - central porjections axons
- corticp reception ares
pushers’ syndrome occurs at what location?
central projections axon
cortical reception areas
s/s of vestibular dx include?
vertigo nausa/vomitting pathologic nystagmus dysequilibrium impaired gaze stabilization vestibular ataxia oscillopsia = no gaze stabilization
oscillopsia means
complete lack of VOR
presents like the camera on C.O.P.S
dysequilibrium means
you’re off balance
vertigo is
the feeling of spinning in the world
pathologic nystagmus is when
you have oscillations of the eyes with no apparent & no appropriate stimulus
impaired gaze stabilization means
that the VOR isn’t working in 1 eye or both but it’s just impaired
vestibular ataxia is when
there is ataxia due to the vestibular system
- unsteady movements
- head problems
if you had oscillopsia what would it look like
your eyes would follow your head no matter what
and the world around you is shaky all the time
connections from the vestibular nuclei to cells of the vestibulospinal tracts would influence
conscious awareness of head position
