VESTIBULAR SYSTEM Flashcards
(24 cards)
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
what can compensate for loss of vestibular system?
eye movement - visual system
as they can send descending projections which control posture
vestibular nystagmus?
series of saccadic eye movements that rotate eye against direction of passive rotation of head and body
nystagmus associated with what reflex?
vestibule-ocular reflex
how can we test nystagmus?
EXPLAIN RESULTS
when outer ear us washed with either warm or cold water
changes the temp of endolymph
warm fluid causes nystagmus toward affected side
cold fluid causes nystagmus away from affect side
COWS - cold opposite/warm same
warm into right - right NYST.
cold into left - right NYST.
HOW TO DEICIED WHAT SIDE IS NYSTAGMUS?
right nystagmus means - slow to left and fkicj back to right side!
how is motion sickness formed?
when inputs from visual and vestibular inputs are conflicting
labrynthitis what is it?
symtom?
acute interference with normal vestibular function as a result of infection in SCC
experience vertigo
VERTIGO is?
hallucination of movement in the absence of movement
Menieres disease?
no infection
vertigo
nausea
nystagmus
tinnitus
overporduction of endolymph causing increase pressure in ears
