6
Semicircular canals are parallel and the anterior canal of the L ear will line up with the ______ canal of the R ear
Hair cells in the ampulla tell us what information?
Info about angular movement
What are the 3 cortical areas in the vestibular pathway?
1. Intraparietal sulcus
2. Sylvian fissures
3. Parietal-insular vestibular cortex
Move the head one way and the eyes are staying forward
- equal and opposite speed of eye movements compared to the head
- can cancel VOR if eyes are moving in the same direction of the head
VOR reflex
Holds images steady on the retina during sustained head rotation
Optokinetic
Stereocilia is inside the ____, which informs nerve what motion is occurring
Cupula
Hair cells in the saccule and utricle tell us what information?
Body moving up and down (elevator), forward and backwards
Linear movement
**** - Lateral vestibulospinal tract descends ipsilaterally
- Medial vestibulospinal tract descends ipsilaterally but innervates bilaterally
Vestibular motor system
Hold images steady on the retina during brief head rotations
Reset the eyes during prolonged rotation and direct gaze toward an oncoming visual scene (ex: ice skater)
Nystagmus quick phases
When you move the head, the endolymph is moving bending the stereocilia and cupula sending signal to vestibular nerve. The endolymph goes ____ the direction we turn
Against
If you turn your head to the L, the L ear is excited, and the R ear is ______.
Inhibited
**** - vestibular nucleus interacts with abducens and oculomotor nuclei
- eye movement equal/opposite to head
Vestibulo-ocular system
Moves the eyes in opposite directions so that images are placed or held simultaneously on both foveas (Pulling medial rectus of both together.. finger starts out and move finger toward their nose and wait until they see 2 objects because close to the nose).
Vergence
Holds the image of a small moving target on the fovea or holds the image of a small near target on the retina during linear self motion: with optokinetic responses, aids gaze stabilization during sustained head rotation
Smooth pursuit
The maculae includes what 3 things:
1. Saccule
2. Utricle
3. Otolith organs
Primary afferents (1st neuron) from the vestibular division of CN VIII travel to where in the vestibular pathway?
Vestibular ganglia
What CN gives us lateral rectus?
CN VI: Abducens
Holds the image of a stationary object on the fovea (not with head movement)
Visual fixation
What two reflexes work together to keep head upright relative to horizon?
1. vestibulocollic
2. vestibulospinal
Hair cells in the cochlea tell us what information?
Sound
2nd neuron to thalamus via ______________ in the vestibular pathway?
Lateral and medial lemnisci (info from both right and left sides)
Which CN activates the medial rectus of one eye and the lateral rectus of the other eye?
CN III: Oculomotor N
Bring objects of interest onto the fovea (going back and forth between two objects)
Saccades
"Dolls eyes" nystagmus
Vestibulo-ocular reflex