Control of Eye Movements Flashcards
What does in the medial longitudinal fasciculus do in horizontal gaze?
It is a white matter tract that connects various cranial nerve nuclei
When do omnipause neurons fire? What is their main role?
Continuously during the saccade
Tell the eyes to stop moving
What are the two types of neurons in the pontine paramedian reticular formation?
Burst neurons and omnipause neurons
Where in the cortex controls saccades?
Frontal eye fields
Posterior parietal cortex
What is the primary action of the superior rectus?
Elevation
Which oculomotor motor muscle in innervated by the abducens nerve?
LR
What do burst neurons do?
Fire at high frequency just before movement
What are optokinetic eye movements?
Holds an image stationery during sustained head rotation or translation
Which rectus muscle muscle do the obliques insert near to?
The lateral rectus
What muscles are involved in horizontal gaze?
MR and LR
What type of eye movement is intorsion?
Rolling upwards and medially
Do the oblique muscles insert behind or infront of the equator?
Behind
How does the vestibular system sense head movement?
Fluid moving across hair bundles in the ampulla of the inner ear
What are saccadic eye movements?
Rapid shifting of the fovea over a new visual target - eg looking at a painting
What is smooth pursuit eye movement?
Keeps the image of a moving target on the fovea
Where in the information from the vestibular system integrated with control of horizontal gaze?
Vestibular nuclei in the medulla
What are the two components of control of gaze?
Oculomotor system - Moves eyes in the orbit
Head-movement system - Moves the eye sockets as a whole
T/F When adducted only the superior oblique can depress
True
Which part of the reticular formation is important in control of horizontal gaze?
The pontine paramedian reticular formation
What must occur in burst and omnipause neurons for eye movement?
Simultaneous excitation of burst neurons and inhibition of omnipause neurons
Which system comes into play when coordinating head and eye movements?
The vestibular
T/F When abducted, only the inferior oblique can elevate
False, the superior rectus elevates when abducted
T/F the Abducens innervates the contralateral eye
False the trochlear does
