Eye and Head Movements Flashcards
which ocular system controls gaze while the head is still?
oculomotor system: extraocular muscles and neural pathways coordinating movement of each eye
which ocular system controls gaze while the head is moving?
head-movement system: moves the eye sockets as a whole while the head moves.
involving vestibular and oculomotor system.
what are saccadic eye movements?
shift fovea rapidly between new visual targets (when looking at different aspect of a painting)
describe smooth pursuit eye mvmts?
keeps the image of a moving target on the fovea
describe ocular vergence?
moves eyes in opposite directions towards the middle to focus on a near object. ie left eye moves right, right eye moves left.
vestibular ocular movements?
holds image still on the retina during brief head movements
optokinetic ocular movements?
holds image still during sustained head rotation or translation
what are the six extraocular muscles acting in 3 antagonist/agonist pairs?
lateral rectus/medial rectus,
superior rectus/inferior rectus,
inferior/superior oblique
where does the superior oblique insert? prime action?
runs through the trochlea (fibrocartilage pulley) and inserts behind the equator at an oblique angle close to the LR.
Acts in Torsion. Brings eye medially and inferiorly.
(opposite of what youd expect)
where does the inferior oblique insert? prime action?
inserts behind the equator close to the LR.
acts in torsion. moves eye medially and superiorly.
opposite of what you’d expect
how do you clinically test the superior rectus?
move eyes laterally and then upwards.
how do you clinically test the superior oblique?
move eyes medially and then inferiorly.
CASE: middle aged male presents with double vision when looking to the sides. Hx of multiple sclerosis. Possible cause?
inter nuclear ophthalmic lesion. medial rectus muscles are deficient bilaterally.
Which nerve innervates MR, SR, IR, IO
oculomotor nerve (III)
which nerve invervates LR?
abducens nerve (VI)
