9.19 Vestibular (Big Concepts) Flashcards
Example of partial redundancy of the balance system
co-planar pairing
How do the paired SCC act together?
push - pull
Orientation of canals: wall
Stand at 45˚ to corner, chin slightly tucked:
- wall you’re facing = anterior canal
- wall behind = posterior canal
- floor = horizontal canal
What is the coplanar pair to the right posterior canal?
L anterior canal
What is the coplanar pair to the left anterior canal
R posterior canal
Quick head turn to R:
Fluid in R horizontal SCC
moves toward midline
Quick head turn to R:
Firing rates on R and L sides
R: firing rate goes up
L: firing rate goes down
Quick head turn to R:
eye movements
Eyes move left (equal and opposite direction)
Sustained spinning to R: endolymph movement
moves relatively toward midline (to L)
phases of peripheral nystagmus
- slow phase
- fast phase
Which phase is the VOR?
slow phase
fast pase is this type of movement
corrective
nystagmus aka
uncontrolled VOR
What is nystagmus?
- rhythmic, uncontrolled eye movement
- slow phase followed by a fast phase in the opposite direction
vascular supply of the peripheral system
NO collaterals to the peripheral system
only takes 5-15 seconds to cause damage
