Oculomotor Lec26 Flashcards Preview

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Flashcards in Oculomotor Lec26 Deck (34)
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1
Q

purpose of the Vestibular Ocular Reflex.

A

 steady the scene against movement

keep focus on object

2
Q

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

A

opposite

3
Q

purpose of OptoKinetic Nystagmus

A

. The eyes can jump focus

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

4
Q

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

A

fovea

5
Q

the ___ decides where saccades should go

A

forebrain

6
Q

Vergence and Accomodation. Adjust the

A

 plane of focus

7
Q

___ Eye Field controls voluntary eye movements

A

Frontal

8
Q

___Cortex controls involuntary pursuit movements

A

Superior Parietal 

9
Q

Vertical gaze center/saccade generator is in the 

A

midbrain, near CN 3 and 4

10
Q

Horizontal gaze center is in the

A

 PPRF (paramedian pontine reticular formation), near CN 6

11
Q

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

A

 contralateral CN 3

12
Q

 Oculomotor Apraxia = lesion to 

A

frontal eye fields 

13
Q

Oculomotor Apraxia leads to loss of 

A

voluntary eye movements

14
Q

___ is preveserved with oculomotor apraxia

A

VOR

15
Q

with oculomotor apraxia cant _____ but can ____

A

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

16
Q

Internuclear Ophthalmoplegia = ___ lesion.

A

MLF

17
Q

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

A

MLF

18
Q

sx of CN 6 palsy 

A

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

19
Q

A saccade requires (2)

A

1.  both a “burst” of firing to overcome inertia and initiate eye movement

2.  a new “tonic” firing rate to maintain the new position:

20
Q

Motor Error: difference between ___ and ___

A

current visual
field and where you want to look

21
Q

baby
whose eyes kept moving was

A

Opsoclonus = Loss of frontal lobe Pause cells..

22
Q

Opsoclonus = Loss of___

A

 frontal lobe Pause cells..

23
Q

Partial Burster Loss is due to damage to the

A

medulla

24
Q

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

A

slowed saccades 

25
Q

Loss of Cerebellar Integrator  causes what dsx

A

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

26
Q

foveal pursuit involves keeping the object on the fovea.

what is moving.. the head or the eyes?

A

the eyes are moving

27
Q

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

A

convergence

28
Q

pursuit movements use the

A

parietal lobe

29
Q

mlf X
the eye moving ___
will be slow

A

inward

30
Q

adducting the eye is slow... always going to be

A

MLF

31
Q

problem with burst cell position 

A

slowed saccades, might not hold position

32
Q

problem with integrator
what would result?

A

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

makea  saccade
but wont hold
with cerebellar disease

33
Q

problem with integrator results from damage to the

A

cerebellum

34
Q

loss of pause cells results in

A

chaotic saccades