The Vestibular System Lecture 12 Quiz 8 Flashcards
what is vestibulo-ocular reflex (VOR)
mechanism that stabilizes images on the retina DURING HEAD MOVEMENT by producing compensatory eye movements in the opposite direction of head movement
what are the actions that we can do with VOR
reading while walking
sports
nodding yes
what is vestibulospinal reflex
coordinates body particularly LIMBS and TRUNK muscles in reponse to head movements to maintain posture and balance
what are the components of the peripheral vestibular system
semicircular canals
ampulla
cupula
otolith organs (utricle, saccule)
hair cells
endolymph
perilymph
what are the components for the central vestibular system
vestibular nerve
CN 8
vestibular nuclei in the brainstem (pons, medulla)
cerebellum
vestibular cortex
what does the cerebellum do in th central vestibular system
coordinates vestibular input for balance and posture
VOR adjustments
how many synapses between the vestibular system and the eyes
3
the pons and medulla are in what nuclei
vestibular nuclei (midbrain)
vestibular cortex detects what
conscious awareness of head position and movement
the central vestibular pathways do what
processed all vestibular input and coordinate all vestibular responses through connections to other areas of the CNS
what does the vestibulocohlear nerve (CN 8) transmit
transmits vestibular information from inner ear to the vestibular nuclei
where is the bony labyrinth located
petrous portion of temporal bone
what does the bony labyrinth contains
cochlea
what does the cilia do
hair cells help translate movement to the brain
what does the utricle do
horizontal motion
what does the saccule do
detects vertical motion
what does the semicircular canal detect
angular movement
what are the structures in the crista
cupula
hair bundles
hair cells
nerve fibers
what are the structures in the macula
otoconia (top layer)
otolithic membrane
kinocilium
type I hair cells
type II hair cells
supporting cells
basement membrane
nerve fibre
when you bend your head forward, what happens to the otoconia ?
moves down
moves the hair cells in the brain to how it translate
what are the 2 arteries that make up the labyrinthine artery
basilar artery
AICA
the peripheral vestibular structures are filled with what
filled with ENDOLYMPH-resembles intracellular fluid
what does the ampulla contain
endolymph
what does the cupula do
endolymph moves to stimulate an action potential transmitting info about movement
