W6_09 Eye Movements

Question 1

what does the lateral geniculate nucleus do?

Answer 1

transmits info from ganglion axons from retina to the primary visual cortex

Question 2

what is superior colliculus for?

Answer 2

reflexive orientation of eyes to strong visual/audial stimulus

Question 3

what types of coordination is the rostral interstitial medial longitudiinal fasciculus responsible for?

Answer 3

vertical gaze

Question 4

what types of coordination is the paramedian pontine reticular formation responsible for?

Answer 4

horizontal gaze

Question 5

how does the vestibulo-ocular reflex work?

Answer 5

semicircular canal fires according to head movements and hits the vestibular nucleus;
interneurons to the CN VI nucleus;
excitation to contra. LR and ipsi. MR

Question 6

which nucleus is responsible for keeping the eyes in place after the horizontal VOR?

Answer 6

nucleus prepositus hypoglossi in the medulla

Question 7

which nucleus is responsible for keeping the eyes in place after the vertical VOR?

Answer 7

interstitial nucleus of Cajal in midbrain

Question 8

optokinetic reflex?

Answer 8

optokinetic nystagmus

Question 9

reflex saccades go through which path?

Answer 9

eye - sup. colliculus - PPRF

Question 10

what does the long path for saccades entail?

Answer 10

PEF - (dorsal lateral) prefrontal (cortex) - FEF - SC - PPRF;
can inhibit the reflex saccades

Question 11

control pathway for horizontal saccades?

Answer 11

frontal cortex,
internal capsule,
PPRF,
CN VI (LR),
MLF,
CN III (MR)

Question 12

how does pursuit work?

Answer 12

instead of positional info, velocity info is encoded;
frontal eye field;
pontine nuclei;
vestibulocerebellum (ipsi);
vestibular nucleus (ipsi);
CN VI;
MLF;
CN III

Question 13

frontal eye field lesion causes eyes to move towards which side?

Answer 13

ipsilateral

Question 14

pontine lesion causes eyes to move towards which side?

Answer 14

contralateral side

Question 15

MLF lesion causes what?

Answer 15

ipsilateral eye can’t adduct (but CAN on convergence)