Exam Three - visual motor Flashcards
duction
eye movement of one eye
intorsion
medial rotation of the eye around its axis
extorsion
top of eye rotates away from the nose
dextroversion
move both eyes to the right
levoversion
both eyes move left
version
both eyes move
vergence
eyes moving in opposite directions
convergences and divergences
extraocular muscles
1 - lateral rectus
2 - superior rectus
3 - superior oblique
4 - medial rectus
5 - inferior rectus
6 - inferior oblque
what muscles do CN 3 innervate
medial, superior, and inferior rectus
inferior oblique
what muscle does CN4 innervate
superior oblique
what muscle does CN 6 innervate
lateral rectus
lateral rectus action
pulls eye laterally
medial rectus action
pulls eyes medially
superior rectus action
brings eye laterally and up
inferior rectus action
brings eye laterally and down
inferior oblique
brings eye medially and up
superior oblique action
brings eye medially and down
3 muscles of the eye lid
1 - levator palperbral (CN3)
2 - orbicularis oculi (CN2)
3 - tarsal muscles
where does CN3 nucleus arise from
midbrain
what composes the oculomotor complex
1 - oculomotor nucleus
2 - caudal central nucleus
3 - Edinger-westphal nucleus
what is right next to the MLF
trochlear nucleus
abducens has connections with oculomotor via ______ for conjugate movements for lateral gaze
MLF
functional classes of human eye movement
1 - vestibular
2 - visual fixation
3 - optokinetic
4 - smooth pursuit
5 - nystagmus quick phases
6 - saccades
7 - vergence
this holds images of the seen world steady on the retina during brief rotations or translations. compensatory for high frequency head movements
vestibular
this holds images of a stationary object on the fovea by minimizing ocular drifts
visual fixation
this holds images of seen world steady on the retina during sustained head rotations
optokinetic
this resets the eyes during prolonged rotation and direct gaze towards the oncoming visual scene
nystagmus
this brings images of objects of interest onto the fovea
saccades
this moves the eyes in opposite directions so that images of a single object are placed or help simultaneously on the fovea
vergence
retinal slip
difference between eye velocity and head velocity
for normal vision retinal slip must be less than
2deg/sec
retinal error induces this
saccadic eye movement which brings fovea to the target
T or F: cervico-ocular reflex has a low gain
T
note: it may help people with labrinthine dysfunction
optokinetic system
supplements the translation of the VOR
combo of saccade and smooth pursuit eye movements to hold gaze on an object during self-motion
smooth pursuit
a type of voluntary eye movement in which the eyes move smoothly to follow a moving object
T or F: smooth pursuit is affected by vestibular loss
F
damage to the smooth pursuit system is often caused by
cerebellar lesions
what is one important function of saccades
visual search of environment
where is the horizontal gaze center located
paramedian pontine reticular formation
where is the vertical gaze center located
midbrain
rostral interstitial nucleus
activation of the gaze centers results in
oblique saccadic movement
the ___ and _____ provide complementary pathways for the control of saccades
frontal eye lids
superior colliculus
3 physiological nystagmus causes
1 - vestibular induced
2 - visually induced
3 - extreme end point induced
2 pathological nystagmus
spontaneous and positional
what is the purpose of vergence
view near objects
what are the 2 primary stimuli for vergence
1 - disparity
2 - retinal blur
T or F: vergence movement is mainly performed unconsciously
T
What CN are you testing when doing far to near vision
CN2 and 3
unilateral oculomotor nerve palsy: lesion on GSE components
ptosis
affected eye will abduct and depress
unilateral oculomotor nerve palsy: lesion on GVE components
loss of pupillary light reflex
resting pupil is large
mydriasis
dilated pupils
what may cause CN3 palsy
congenital
ischemia
aneurysm
tumor
this accounts for most causes of acquired vertical stabismus
CN4 palsy
CN4 palsy
vertical and torsional diplopia that is worse when looking down
the effected eye will elevate and extort
this is the most common ocular motor palsy
CN6 palsy
CN6 palsy
medially directed eye that cannot abduct
horizontal diplopia
strabismus
misalignment of visual axes
diplopia
any interruption in the sympathetic system to the eye will result in this
Horner’s syndrome
T or F: symptoms of horner’s syndrome occur on the contralateral side of lesion
F: ipsilateral
symptoms of horner’s syndrome
ptosis, miosis, anhidrosis, enophthalamus
anhidrosis
abnormal condition of no sweat
enophthalamus
sunken eyes