Central pathway: vision Flashcards

1
Q

Unilateral optic nerve lesion

A

a. blindness in affected eye only

b. location: in optic tract

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2
Q

a. blindness in affected eye only

b. location: in optic tract

A

Unilateral optic nerve lesion

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3
Q

Lesion of optic chiasm

A

a. bitemporal hemianopia; interupts fibs from nasal portions of retina
b. horse with blinders—loss of peripheral vision

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4
Q

a. bitemporal hemianopia; interupts fibs from nasal portions of retina
b. horse with blinders—loss of peripheral vision

A

lesion of optic chaism

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5
Q

Unilateral optic tract lesion

a. get __________hemianopia (same side/half/vision impairment)

A

contralateral homonymous

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6
Q

Location of unilateral optic tract lesion is:

A

Location is optic tract post chaism

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7
Q

Fibers interrupted on a unilateral optic tract lesion

A

c. interrups fibs from temporal parts of retina on the ipsilateral side and the nasal protion of the opp side

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8
Q

Unilateral optic tract lesion of left side affects which side/visual field

A

get right side of both field affected

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9
Q

Unilateral lesion of optic radiation in anterior temopral lobe (meyers loop)

A

End up with contralateral upper quadrantanopia—bc fibers wind around inferior horn of lateral ventricle in temporal lobe

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10
Q

End up with contralateral upper quadrantanopia—bc fibers wind around inferior horn of lateral ventricle in temporal lobe

A

Unilateral lesion of optic radiotionin anterior temporal lobe (meyers loop)

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11
Q

Unilateral lesion in medial part of optic radiation in parietal lobe

A

contralateral lower quadrantanopia

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12
Q

b. affected fibers course superior and usually lesion is in parietal lobe
c. if on left side, you loose LR quadrant of both eyes

A

Unilateral lesion in medial part of optic radiation in parietal lobe

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13
Q

causes homonymous hemianopia

A

occipital lobe lesion

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14
Q

B/c optic radiations fan out widely b4 entering visual cortex, lesions of occipital lobe often will

A

spare foveal vision

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15
Q

Most common cause of occipital lobe lesion

A

intracerebral hemorrhage

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16
Q

Lesion of cortical area of occipital pole represent

A

macula thus we get homonymous hemianopic central scotoma

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17
Q

Direct pupillary light reflex

A

response in the stimulated eye

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18
Q

Consensual reflex

A

response in unstimulated eye

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19
Q

Lesion on optic tract of one side (right eye)–shine light in right eye, you will __________
–shine light in left eye, you will _________

A

not get direct or consensual constriction

get both direct and consensual constriction

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20
Q

Lesion on right Ed/Wes

A
  • -shine light on right eye, signal goes to both Ed/Wes nuclei-
  • since right Ed knocked out, no direct constriction but will get consensual constrction
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21
Q

Lesion of pretectal area of right side

A

–Get both direct and conensual:
keep in mind fibers cross at optic chiasm so you will trigger the left path and right path. Once we get to pretectal area, they project contra/ipsi to the Ed/Wess so even if the right pretectal cant stimulate the right Ed, the left pretectal will

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22
Q

Suprachiasmitic nucleus is good for

A

circadian clock and melatonin production

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23
Q

This keeps track of fast moving objects in periperphy and helps you reponsd quickly

A

Superior colliculus

24
Q

This is key for spatial neglect, only attend to or pay attention to one side

A

pulvinar of thalamus

25
Q

Pathway: light enters on retina→ will go through _______and tract (follows same pattern as vision)
→ BYPASSES the_____ and instead synapses on the______ area in the midbrain.
→ fibers go contralatreal and ipsilateral to the _______
→ from Ed/Wes nuclei sends out pregang____ fibers that exit the midbrain , hop on the_____ nerve and stay contralateral til they synpase on ______
→ from ciliary gang, post-syn PNS head to the pupillary sphincter via the _______

A
optic nerve (CN II) 
LGN
Pretectal
Ed/Wes nuclei
PNS
oculomotor
ciliary gang
short ciliary nerves
26
Q

recieves input from parasol cells, key for quick movemnt

A

Superior colliculus

27
Q

The superior colliculus has output to

A

tectospinal tract for head/trunk mvmt

28
Q

What maintains division between neurons/circuits that carry motion-related signals and those that carry color/form and content

A

maintained from retina through LGN via striate cortex

29
Q

Striate cortex is then _______ on retinotipoc representation and are mapped

A

superimposed

30
Q

Area 17

A

Primary visual cortex

31
Q

Area 18 and 19 are

A

extra striate cortex

32
Q

V5 is also called

A

middle temporal (MT)

33
Q

Striate cortex is

A

V1

34
Q

RFs are smallest in

A

V1 then get larger

35
Q

Further you get from V1, the precision is

A

poor

36
Q

Damage to V4 results in

A

impairement for color discrimination tasks

37
Q

Damage to V4/5 is associated with impairment in:

A

dectection of motion

38
Q

Bilateral damage to human homologue V4 produces

A

global impairement of color perception

39
Q

Bilateral damage to MT produces sudden global impairement in

A

ability to detect motion: freeze frame disease

40
Q

freeze frame lesion

A

cerebral akinetopsia, bilateral lesion at MT

41
Q

Lesion of extrastriate areas have segregated function thus outputs from V1 are

A

also segregated

42
Q

In V1 we see anatomical segregation based on:

A

color, form and motion

43
Q

inability to recognize a face is damage to

A

V4

44
Q

V1 projects heavily into

A

V2

45
Q

Lesion here impair allocation of attention or attentional neglect

A

pareital lobe lesion

46
Q

lesion here impair recogntion (based on size, color, texture)

A

temporal lobe lesion

47
Q

V1–> V2–>MT is the

A

dorsal pathway leading to parietal lobe

48
Q

V1–>V2–> V4 is the

A

ventral pathway leading to temporal lobe

49
Q

furtherst downstream from V4 and receptive fields are huge

A

Inferotemporal complex

50
Q

damage to part of fusiform gyrus produces

A

selective impairment in recognition of faces

51
Q

visuospatial neglect is due to damage to

A

parietal cortex

52
Q

ventral stream heads to

A

temporal lobe

53
Q

dorstal stream heads to

A

parietal lobe

54
Q

High level brain structures that recieve input on
memory
intention
emotion

A

hippocampus
prefrontal cortex
limibic system

55
Q

Broadman area 18-19 account for at least _____ areas with their own map of visual space

A

9

56
Q

Ventral stream: Face area is in:

A

IT cortex