Vestibular System Flashcards
what area of the vestibular system measures angular motion?
semicircular canals
what area of the vestibular system measures linear motion?
vestibule
multimodal convergence?
all of the systems help to keep you coordinated. Ex. stand on one leg with eyes close and use 1 finger on table to balance
1st writing response?
lift head
where is endolymph located?
inside membranous labyrinth of cochlea
what is endolymph?
identical to CSF except with high potassium
where is perilymph located?
inside membranous labyrinth of the semicircular canals
what is perilymph?
identical to CSF except high sodium
orientation of the horizontal canal?
parallel to gravity (30 degrees up)- this is why you lean your head forward to optimize the vestibular and visual field when running.
what type of cells are the hair cell in the inner ear?
modified epithelial cells
what are the 6 steps for how a hair cell transmits a signal?
- movement of head
- filament btwn cillia is pulled
- potassium stretch channels open
- potassium removed
- high potassium depolarizes, calcium channels open and neurotransmitter released
- neuronal (ganglion) projection - receives neural transmission from epithelial cells
what regulates the discharge rate of the hair cells?
potassium concentration
- hair cells have a high tonic firing rate
what are two structures that help to overcome inertia?
copula and otolith membrane
what is the copula?
when is it used?
- filled with high viscosity fluid that helps to transmit a signal from one side to the other and to overcome inertia
- angular (rotational) movement
function of the utricle
integrate angular & linear movement
function of the saccule
measure linear movement (gravity)
what happens if you break the otolith membrane?
vertigo
interactions of the otoconia and otolith membrane?
calcium carbonate crystals of the otoconia go up and then come back down on the otolith membrane.
-linear acceleration
linear acceleration
gravitational
angular accelecation
rotational movement
function of the vestibulocerebellar tract?
coordinate angular motion to the cerebellum (by passes the cranial nerves)
angular epithelial cells in relation to the central vestibular nucleus go to what 4 locations?
angular- roational goes up!!
- Medial vestibular nucleus
- Lateral vestibular nucleus
- Superior vestibular nucleus
- Juxtarestiform body (cerebellum)
linear epithelial cells in relation to the central vestibular nucleus go to what 4 locations?
linear - gravity goes down!!!
- Medial vestibular nucleus
- Lateral vestibular nucleus
- Inferior vestibular nucleus
- Cell group Y
what is the slow phase of the vestibuloocular pathway?
turn head, eyes move opposite direction
- eyes move off the point of attention
what is the fast phase of the vestibuloocular pathway?
turn head, eyes move back to the target very fast
what happens in caloric nystagmus when warm water is added to the right ear?
eyes go slowly to the ground first and then rapidly to the ears
what happens in caloric nystagmus when cold water is added to the right ear?
eyes go slowly to the sky and then fast to the ground
what happen to the endolymph when warm water is added to the ear?
it rises
the vestibulo-thalamic cortical networks does what?
conscious perception of motion = spatial orientation
destination of the vestibulo-thalamic cortical networks?
VPL, VPM, Vi of Thalamus to cortex
function of the vestibulospinal pathway?
coordinate head movements, posture axial muscular coordination
a person with a left nystagmus in the vestibulospinal pathway - what happens?
they will fall / stumble to the right
