Eye Movements Flashcards Preview

Jason's Neuro Block > Eye Movements > Flashcards

Flashcards in Eye Movements Deck (22):
1

what are the two components to stabilize image on retina?

1. occulomotor system: eye in socket
head movement system: socket as whole with vestibular system

2

Saccades does what to image?

shift fovea rapidly to new target

3

what does smooth pursuit do?

keeps image of moving target on fovea

4

what does optokinetic movements do?

holds image still during sustained head rotation

5

6 extraocular muscles:

Superior Rectus
Inferior Rectus
Medial Rectus
Lateral Rectus

Inferior Oblique
superior Oblique

6

Superior oblique movements?

torsion and depression adduction

7

inferior oblique movements?

torsion and elevation

8

Superior Oblique muscles innervated by?

trochlear: CNIV

9

Lateral Rectus muscle innervated by?

Abducens: CN VI

10

trochlear CN IV innervates which superior oblique?

the CONTRALATERAL one...

11

what connects white matter tracts between cranial nerve nuclei?

medial longitudinal fasciculus (MLF)

12

what reticular formation in the pons for coordinated eye movements?

pontine paramedian reticular formation

13

what reticular formation in the midbrain for coordinated eye movements?

mesencephalic paramedian reticular formation

14

What does Pontine RF coordinate? which nerves?

horizontal gaze
(MR)CN III and (LR)CNVI

15

what does midbrain RF coordinate?

vertical gaze
(SO) CN IV and (SR)CN III

16

two kinds of neurons fire during horizontal saccades?

burst neurons before movement
omnipause neurons fire when eye not moving

17

Omnipause neurons do what?

inhibit via GABA

18

Burst neurons do what kind of signalling?

excitatory for ipsilateral abducens
inhibitory for contralateral abducens

19

what do you need for neural control of saccades?

simultaneous burst and inhibition of omnipause

20

eye movements ultimately driven by?

behaviour

21

what drives brainstem gaze centres? 5 things

frontal eye fields
post parietal cortex
superior colliculus
basal ganglia
cerebellum

22

which nerves needed coordinates head and eye movements together?

vestibulocochlear to medulla nuclei with CNIII, CNVI nuclei