Vestibular A&P Flashcards
what 3 primary brain structures does the vestibular system project info to?
- cortex
- brainstem
- cerbellum
what are the 3 primary functions of the peripheral vestib system?
- stabilize visual images on the fovea of the retina during head movement to allow for clear vision
- maintain postural stability, esp during head movement
- provide info for spatial orientation
the utricle detects movement in what plane?
horizontal
the saccule detects movement in what plane?
vertical
where are the stereocilia found in the utricle?
on the floor
how is the kinocilium positioned in the utricle?
towards midline
where are the stereocilia found in the saccule?
on the medial wall
how is the kinocilium positioned in the saccule?
towards lateral edges
the semicircular canals relay info re: ____ of the head
angular velocity
T/F: the endolymph in the SCCs is gravity dependent
false
how are direction of endolymph movement and direction of rotation related in the SCCs?
they’re opposite (ex: head rotates L, fluid moves R)
the hair cells in the SCCs are sensitive to ____ movements only
angular
utriculopedal cupular displacement is excitatory for the ____ canal and inhibitory for the ____ canal
- excitatory for horizontal
- inhibitory for A/P
utriculofugal cupular displacement is excitatory for the ____ canal and inhibitory for the ____ canal
- excitatory for A/P
- inhibitory for horizontal
what artery supplies the vestibular labyrinth?
labyrinthine artery
what artery does the labyrinthine artery originate from?
AICA (sometimes branches straight off basilar a.)
what are the 2 branches of the labyrinthine artery?
- anterior vestibular a.
- common cochlear a. (main cochlear a. + vestibulocochlear a)
what structures are supplied by the anterior vestibular a?
- utricle
- vestibular n.
- ampullae of ant and horizontal SCC
what structures are supplied by the common cochlear a?
- cochlea
- ampulla of post SCC
- saccule
what is significant about the labyrinthine artery?
it is HIGHLY susceptible to ischemia
what does the VOR do?
generates eye movements that enable clear vision while head is in motion
what does the VSR do?
generates compensatory body movement to maintain head and postural stability
what does the VCR do?
act on neck musculature to stabilize the head
what does the COR do?
- interacts closely with VOR, can supplement
- eye movements driven by neck proprioceptors
what does the CSR do?
- changes in limb position driven by neck afferent activity
- can supplement VSR
what does the CCR do?
- help stabilize head on body
- afferent input from change in neck position (stretch) leads to contra. reflexive contraction of appropriate neck muscles
what are the 4 sets of vestibular subnuclei?
- lateral nucleus
- medial nucleus
- superior nucleus
- inferior nucleus
what is the job of the lateral nucleus?
principle vestibular relay
what is the job of the medial nucleus?
VOR and VSR relay
what is the job of the superior nucleus?
VOR relay
what is the job of the inferior nucleus?
cerebellar and RF relay
describe the lateral vestibulospinal tract
- travels to thoracic SC to extensor muscles
- head/body position in space
- walking upright
- righting and equilibrium reactions
describe the medial vestibulospinal tract
- travels to cervical SC to extensor muscles
- head movements
- integrates head and eye movements
T/F: there is no primary vestibular cortex
true
describe the parieto-insular vestib cortex (PIVC)
- receives input from cerebellum and vestib nuceli via thalamus
- visual, somatosensory, and vestib integration
- optokinetic nystagmus
describe the medial superior temporal region
- visuo-vestibular integration
- self-motion perception
describe the ventral intraparietal region
- spatial orientation
- proprioceptive, auditory, visual, tactile, vestib integration
