Ocular Motility

Question 1

T or F:

Neurological pathways governing ocular motility are independent of vision

Answer 1

TRUE

Question 2

CN III control what extraocular muscles?

Answer 2

Superior, inferior and medial recti, inferior oblique

Question 3

CN IV controls what extraocular muscle?

Answer 3

Superior oblique

Question 4

CN VI controls what extraocular muscle?

Answer 4

Lateral rectus

Question 5

Primary Action of Medial rectus

Answer 5

Adducts

Question 6

Primary Action of Lateral rectus

Answer 6

Abducts

Question 7

Primary Action of Superior rectus

Answer 7

Elevates

Question 8

Primary Action of Infereior rectus

Answer 8

Depresses

Question 9

Primary Action of Superior oblique

Answer 9

Depresses

Question 10

Primary Action of Inferior oblique

Answer 10

Elevates

Question 11

Neural mechanisms that govern eye movements reside mainly in the

Answer 11

Midbrain and Pons

Question 12

Symmetrical and synchronous movement of the eyes

Answer 12

Conjugate movement of the the eyes

Question 13

Simultaneous movement of the eyes in the opposite direction

Answer 13

Disconjugate or disjunctive

Question 14

Rapid movements of the eyes that serve to fixate on a target

Answer 14

Saccades

Question 15

Following movements of the eyes when they are fixated on a moving
target

Answer 15

Smooth pursuit

Question 16

Disconjugate eye movements which serve to maintain binocular single vision
and depth perception

Answer 16

Vergence

Question 17

Maintains the eyes on a target by constant tonic contraction of the extraocular
muscles (gaze holding)

Answer 17

Fixation

Question 18

If a series of visual targets enters the visual field, as when one is
watching trees from a moving car, ot the stripes of a rotating drum, repeated quick saccades
refocus the eyes centrally; the resulting repeated cycles of pursuit and refixation are termed

Answer 18

optokinetic nystagmus

Question 19

Means of this reflex, a movement of the eyes is produced that is
equal and opposite to movement of the head

Answer 19

Vestibulo-ocular reflex

Question 20

Controls horizontal saccades to the opposite side

Answer 20

frontal eye fields (FEF)

Question 21

All the pathways mediating saccadic and pursuit movements in the horizontal plane
as well as vestibular and optokinetic movements converge on

Answer 21

pontine centers for horizontal gaze

Question 22

Generally under BILATERAL control of the cerebral cortex and the upper brainstem, govern upward and downward gaze are situated in the pretectal areas of the midbrain

Answer 22

vertical eye movements

Question 23

Any lesion which can affect the frontal eye fields and the pathway down to
the PPRF

Answer 23

Central Disorders

Supranuclear

Question 24

Lesion between between the PPRF and cranial nerve nuclei

Answer 24

Central Disorders

Internuclear

Question 25

Contralateral (with respect to the PPRF) medial rectus does not receive a signal to contract
Labeled by the side with adduction failure

Answer 25

Internuclear Opthalmoplegia (INO) or Medial Longitudinal Fasciculus Syndrome

Question 26

conjugate gaze palsy to one side (“one”) and

impaired adduction on looking to the other side (“and a half”)

Answer 26

“The one and half syndrome”

Question 27

Usually results from a mass lesion involving the region of the posterior third ventricle and upper
dorsal midbrain

Answer 27

Parinaud Syndrome

Question 28

Also known as Sylvian aqueduct syndrome, dorsal midbrain syndrome, or the syndrome of the posterior commissure.

Answer 28

Parinaud Syndrome