VESTIBULAR SYSTEM Flashcards
UTRCILE for what type of movement?
back/front tilt
horizontal acceleration
saccule for what type of movement?
vertical acceleration
semi-circular canals for what type of movement?
rotational acceleration
how are hair cells in ampulla organised?
how AP created?
inside swellings -
hair cells embedded in flexible cupulla
this becomes distort by movement of endolymph fluid in canals
then form AP and send nerve signal to brain and brain knows of movement
where is cupula sending nerve signal?
in through vestibular nerve
cristae in ampulla contain?
cupula and hair cells
where is maculae?
in both otolith organs
hair cells - two types ?
1 large kinocilium
and series of smaller stereo cilia
distortion of cilia in direction and away from kinocilium causes what?
in direction of kinocilium - causes depo. and increase in discharge of AP in vestibular nerve
away from kinocilium - causes hyper polarisation and decrease in discharge of AP in vestibular nerve
what places do vestibular nerve get info from?
- three ampulla of SCC
2. 2 maculae of otolith organs
vestibular information go where?
cerebellar centres OR
vestibular nuclei in brainstem medulla
info from vestibular nuclei in brainstem go where? 3
- motor pathways to muscles
- cerebral cortex for spatial awareness
- eye muscles
tonic labyrinthine reflex ?
keep axis of head upright and stable and in constant relationship with rest of body -
use of maculae and proprioceptors
dynamic righting reflexes?
rapid postural adjustments that made to stop u from falling when trip -
long reflex involving limbs
vestibule-ocular reflex?
an association between vestibular, visual and postural control
keep gaze as you move head
