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aNeuro Exam 3- Lindsey's > Eye Movements > Flashcards

Flashcards in Eye Movements Deck (55)
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1

What is the representation of the optic disk in the visual field?

the blind spot

2

This is moving the fovea to an object closer (convergence) or farther away (divergence).

vergence

3

What signals the rotation of the head?

the semicircular canals

4

Saccades can be voluntarily generated by the _____.

frontal eye field (FEF)

5

The oculomotor system is subject to modulation by the ____ and ____.

cerebellum; basal ganglia

6

What is inhibited during conjugate gaze?

antagonist motor neurons

7

When is nystagmus normal?

when the head is rotated for along time or when there is a moving visual stimulus

8

What initiate conjugate eye movements?

a variety of sensory inputs, especial visual and vestibular

9

What are the 2 important control centers for saccades?

  1. the cortex
  2. the superior colliculus

10

If the head turns to the right, the eyes ____.

counter rotate to the L

11

Smooth pursuit can only maintain foveation at a rate of about _____.

50 degrees/second

12

The direction of the nystagmus is defined by _____.

the direction of the rapid saccade

13

What are saccades?

rapid, ballistic eye movements (to bring an object onto the fovea)

14

Where is the pattern generator for horizontal saccades?

in the reticular formation near the abducens nucleus (the paramedian pontine reticular formation- PPRF)

15

What eye condition do MS patients often get?

internuclear ophthalmoplegia (INO)

16

Cells in the vestibular nuclei project by way of the ______ to excite lateral rectus motor neurons in the abducens nucleus.

medial longitudinal fasciculus (MLF)

17

Saccades can be reflexively directed from the _____.

parietal eye field (PEF)

18

If the frontal eye field is damaged, the is a _____.

temporary loss of the ability to generate saccades

19

Interruption of the _____ can cause discoordination of medial and lateral recti muscles during horizontal gaze movements, called internuclear ophthalmoplegia (INO).

medial longitudinal fasciculus (MLF)

20

Coordinate contraction of the 2 eyes is accomplished by _____ that reside in the vicinity of the oculomotor and abducens nuclei.

interneuronal pattern generators

21

What is an example of a vergence movement?

when both eyes turn towards the nose for near reading

22

Horizontal saccades are driven ____.

contralaterally

23

What are the vestibular ocular reflex (VOR) and optokinetic nystagmus (OKN) eye movements?

a combination of pursuit and saccades

24

What is the frontal eye field?

an area near the motor cortex that activates saccades via the reticular formation and/or the superior colliculus

25

Who often gets internuclear ophthalmoplegia (INO)?

MS patients

26

What is vergence?

moving the fovea to an object closer (convergence) or farther away (divergence)

27

Interruption of the medial longitudinal fasciculus (MLF) can cause ______, called internuclear ophthalmoplegia (INO).

discoordination of medial and lateral recti muscles during horizontal gaze movements

28

What are microsaccades?

the eye moving in small jumps to refresh the image several times/sec so it is never stabilized

29

The medial longitudinal fasciculus (MLF) is especially vulnerable to interruption bc of _____.

its length

30

Movement brings the fovea to an area that was being analyzed by _____.

that side of the brain