Control of Eye Movements Flashcards

1
Q

What does in the medial longitudinal fasciculus do in horizontal gaze?

A

It is a white matter tract that connects various cranial nerve nuclei

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1
Q

When do omnipause neurons fire? What is their main role?

A

Continuously during the saccade

Tell the eyes to stop moving

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2
Q

What are the two types of neurons in the pontine paramedian reticular formation?

A

Burst neurons and omnipause neurons

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2
Q

Where in the cortex controls saccades?

A

Frontal eye fields

Posterior parietal cortex

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3
Q

What is the primary action of the superior rectus?

A

Elevation

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3
Q

Which oculomotor motor muscle in innervated by the abducens nerve?

A

LR

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3
Q

What do burst neurons do?

A

Fire at high frequency just before movement

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5
Q

What are optokinetic eye movements?

A

Holds an image stationery during sustained head rotation or translation

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6
Q

Which rectus muscle muscle do the obliques insert near to?

A

The lateral rectus

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7
Q

What muscles are involved in horizontal gaze?

A

MR and LR

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9
Q

What type of eye movement is intorsion?

A

Rolling upwards and medially

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9
Q

Do the oblique muscles insert behind or infront of the equator?

A

Behind

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9
Q

How does the vestibular system sense head movement?

A

Fluid moving across hair bundles in the ampulla of the inner ear

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10
Q

What are saccadic eye movements?

A

Rapid shifting of the fovea over a new visual target - eg looking at a painting

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12
Q

What is smooth pursuit eye movement?

A

Keeps the image of a moving target on the fovea

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13
Q

Where in the information from the vestibular system integrated with control of horizontal gaze?

A

Vestibular nuclei in the medulla

15
Q

What are the two components of control of gaze?

A

Oculomotor system - Moves eyes in the orbit

Head-movement system - Moves the eye sockets as a whole

17
Q

T/F When adducted only the superior oblique can depress

A

True

19
Q

Which part of the reticular formation is important in control of horizontal gaze?

A

The pontine paramedian reticular formation

20
Q

What must occur in burst and omnipause neurons for eye movement?

A

Simultaneous excitation of burst neurons and inhibition of omnipause neurons

21
Q

Which system comes into play when coordinating head and eye movements?

A

The vestibular

22
Q

T/F When abducted, only the inferior oblique can elevate

A

False, the superior rectus elevates when abducted

23
Q

T/F the Abducens innervates the contralateral eye

A

False the trochlear does