Oculomotor Lec26

Question 1

purpose of the Vestibular Ocular Reflex.

Answer 1

steady the scene against movement

keep focus on object

Question 2

Vestibular Ocular Reflex. The eyes move ___ of how the head moves to
keep focus on an object

Answer 2

opposite

Question 3

purpose of OptoKinetic Nystagmus

Answer 3

. The eyes can jump focus

ex. switching targets as we
walk - also steadies the scene against movement

Question 4

Saccades. Fast eye movements to shift the visual scene onto the ___

Answer 4

fovea

Question 5

the ___ decides where saccades should go

Answer 5

forebrain

Question 6

Vergence and Accomodation. Adjust the

Answer 6

plane of focus

Question 7

___ Eye Field controls voluntary eye movements

Answer 7

Frontal

Question 8

___Cortex controls involuntary pursuit movements

Answer 8

Superior Parietal

Question 9

Vertical gaze center/saccade generator is in the

Answer 9

midbrain, near CN 3 and 4

Question 10

Horizontal gaze center is in the

Answer 10

PPRF (paramedian pontine reticular formation), near CN 6

Question 11

The MLF, medial longitudinal fasciculus, gets both eyes to move together by activating the

Answer 11

contralateral CN 3

Question 12

Oculomotor Apraxia = lesion to

Answer 12

frontal eye fields

Question 13

Oculomotor Apraxia leads to loss of

Answer 13

voluntary eye movements

Question 14

___ is preveserved with oculomotor apraxia

Answer 14

VOR

Question 15

with oculomotor apraxia cant _____ but can ____

Answer 15

can’t “look right” on command but can still follow a finger to the right

Question 16

Internuclear Ophthalmoplegia = ___ lesion.

Answer 16

MLF

Question 17

with ___ lesion R. eye will not adduct when asked to look left voluntarily, but can move when
following a finger

Answer 17

MLF

Question 18

sx of CN 6 palsy

Answer 18

the eye can’t move laterally, either voluntarily or involuntarily

Question 19

A saccade requires (2)

Answer 19

1. both a “burst” of firing to overcome inertia and initiate eye movement
2. a new “tonic” firing rate to maintain the new position:

Question 20

Motor Error: difference between ___ and ___

Answer 20

current visual
field and where you want to look

Question 21

baby
whose eyes kept moving was

Answer 21

Opsoclonus = Loss of frontal lobe Pause cells..

Question 22

Opsoclonus = Loss of___

Answer 22

frontal lobe Pause cells..

Question 23

Partial Burster Loss is due to damage to the

Answer 23

medulla

Question 24

Partial Burster Loss (damage to medulla) results in what sx

Answer 24

slowed saccades

Question 25

Loss of Cerebellar Integrator causes what dsx

Answer 25

can look R. or L, but
can’t hold the new position.

Question 26

foveal pursuit involves keeping the object on the fovea.

what is moving.. the head or the eyes?

Answer 26

the eyes are moving

Question 27

bilateral oipthalmoplegia.. only one of the things that is nml is ___

Answer 27

convergence

Question 28

pursuit movements use the

Answer 28

parietal lobe

Question 29

mlf X
the eye moving ___
will be slow

Answer 29

inward

Question 30

adducting the eye is slow… always going to be

Answer 30

MLF

Question 31

problem with burst cell position

Answer 31

slowed saccades, might not hold position

Question 32

problem with integrator
what would result?

Answer 32

new tonic firing rate wouldnt be there
so it would drift back

makea saccade
but wont hold
with cerebellar disease

Question 33

problem with integrator results from damage to the

Answer 33

cerebellum

Question 34

loss of pause cells results in

Answer 34

chaotic saccades