Vision Flashcards

1
Q

fovea

A

Central fixation point for each eye

Area of retina with highest visual acuity

Surrounded by the macula
Projects to the occipital lobe

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2
Q

cones

A

color
higher resolution

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3
Q

outermost layer

A

photoreceptors

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4
Q

ganglion cells

A

parasol cells- larger diameter/ gross features and movement
midget cells- small diameter/ details

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5
Q

nasal fibers sees

A

lateral visual field

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6
Q

optic tract damaged

A

contralateral visual field is damaged

contralateral homonymous hemianopia

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7
Q

LGN damage

A

damage contralateral visual field

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8
Q

extrageniculate visual pathways

A

Minority of fibers in the optic tract bypass the LGN to enter the superior colliculus and pretectal areas to form this

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9
Q

pretectal and superior colliculus

A

directing visual attention and eye movements toward visual stimuli

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10
Q

axons leaving the LGN project to

A

the primary visual cortex PVC

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11
Q

fibers of inferior radiations arc forward into

A

temporal lobe forming meyers loop

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12
Q

fibers of superior optic radiations pass

A

Under the parietal lobe

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13
Q

Primary visual cortex

A

lies on the upper and lower banks of the calcarine fissure in the occipital lobe

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14
Q

calcarine fissure

A

cuneus wedge- upper bank gyrus

lingula “little tongue”- lower bank gyrus

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15
Q

superior optic radiations project

A

To the upper bank of the calcarine fissure

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16
Q

inferior optic radiations project

A

To the lower bank of the calcarine fissure

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17
Q

The primary visual cortex is organized

A

retinotopically

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18
Q

retina and macula are represented at the

A

occipital pole

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19
Q

peripheral regions of retinas are represented

A

anteriorly along calcarine fissure

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20
Q

dorsal pathways project to

A

Parieto occipital association cortex

Motion spatial relations

21
Q

Ventral pathways project to

A

Occipito temporal association cortex

form, color, and letters

22
Q

two major steps needed to assess visual disturbances

A

Nature of the visual disturbance

Visual field

23
Q

nature of the visual disturbance

A

Time course and any positive phenomena or negative phenomena

24
Q

Visual field

A

Description of the regions for each eye involved

25
Q

Positive formed phenomena

A

formed visual hallucinations arise from the inferior temporooccipital visual association cortex

26
Q

macular sparing

A

partial lesions of visual pathway

Usually a result of cortical lesions

27
Q

Retinal blood supply

A

Ophthalmic artery

28
Q

What supplies, the inner retinal layers

A

Central retinal artery

A branch of the opthalamic artery

29
Q

two main branches of the retinal artery

A

Superior and inferior

30
Q

an occlusion of what branch would cause a loss in the right inferior VF

A

Superior branch of the right central artery

31
Q

amaurosis fugax

A

transient occlusion of the superior or inferior branch of the retinal artery

Browning out
Lasts 10 minutes
It’s a warning sign
Common cause is ipsilateral ICA stenosis

32
Q

Optic nerves, optic chasm and optic tracks received blood supply from

A

Numerous small branches of the anterior cerebral artery and middle cerebral artery

33
Q

infarcts in the LGN would cause what type of deficit

A

Contralateral homonymous hemianopsia

34
Q

optic radiation passing through the parietal lobe receive blood from

A

Superior divisions of the MCA

35
Q

inferior optic radiation passing through the temporal lobe receive blood from

A

Inferior divisions of the MCA

36
Q

Primary visual cortex supplied

A

By the PCA

37
Q

if there is a right posterior cerebral artery infarct

A

Visual loss in the left VF homonymous hemianopsia

The right PCA supplies the right visual cortex which gets information from the left visual field

38
Q

Pupillary light reflex

A

optic nerve, optic tract, pretectal area, pretectal neurons, bilateral edinger westphal nuclei, ciliary ganglion, constrictor muscles

Direct response and consensual response

39
Q

Gaze stabilizers

A

optoKinetic nystagmus (OKN)
vestibulo-ocular reflex (VOR)

40
Q

direction of gaze

A

saccades
smooth pursuit
vergence

41
Q

OKN

A

optokinetic nystagmus

optokinetic system- eyes follow large objects in visual field

42
Q

OKN path

A

retina
optic nerve chiasm tract
pretectal area
medial vestibular nucleus
ocular motor nuclei
extraocular muscles

43
Q

VOR

A

stabilizes the eyes on a visual image during head and body movements

Vestibular receptors in the semi circular canals

44
Q

saccades

A

rapid eye movements directed at targets in the visual field

45
Q

smooth pursuit

A

Slower movements, following objects in visual field

46
Q

vergence

A

Movements to maintain visual fixation of objects, moving toward or away from the viewer

47
Q

convergence is produced by

A

Medial recti muscles

48
Q

divergence is produced by

A

Lateral recti muscles