Visual System Pathways Flashcards Preview

Neuro Block 3-RG > Visual System Pathways > Flashcards

Flashcards in Visual System Pathways Deck (27)
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1
Q

What part of the thalamus do the cranial tracts terminate?

A

LGN (lateral geniculate nucleus)

2
Q

What “Area” is the primary visual cortex?

A

Area 17

3
Q

What “Areas” are the visual association cortex?

A

Areas 18 and 19

4
Q

How many neurons does it take to get from the eye to the LGN?

A

3

5
Q

What are the 1˚, 2˚, and 3˚ afferents from the eye?

A

1˚: receptors
2˚: bipolar cells
3˚: ganglion cells

6
Q

Which cells form the optic nerve?

A

ganglion cells (3˚ retinal cells)

7
Q

What are the two types of visual fields?

A

retinal and visual

8
Q

Images are both ______ and ______

A

inverted and flipped

9
Q

The optic nerve is an outgrowth of which embryological structure?

A

diencephalon

10
Q

The optic chiasm sits on what cranial structure?

A

sella turcica

11
Q

What structure is located immediately behind the optic chiasm

A

pituitary gland

12
Q

The optic tract carries information from the contralateral/ipsilateral visual field

A

contralateral

13
Q

What is retinotopic organization?

A

lower visual field located more medially

14
Q

What is the name of the fiber bundle that runs from the LGN?

A

optic radiation

15
Q

The sublenticular portion of the optic radiations carries 4˚ neuron fibers from what visual field?

A

upper visual field

16
Q

The retrolenticular portion of the optic radiations carries 4˚ neuron fibers from what visual field?

A

lower visual field

17
Q

What type of defect can occur after damage to either the sublenticular or retrolenticular lateral geniculate nucleus?

A

loss of 25% of visual field

18
Q

The sublenticular optic tract carries axons to what structure?

A

lingual

19
Q

The retrolenticular optic tract carries axons to what structure?

A

cuneate

20
Q

The dorsal stream of the association visual cortex runs through what portion of the brain?

A

parietal/temporal cortex

21
Q

The dorsal stream of the association visual cortex is responsible for what type of processing?

A

where?

22
Q

The ventral stream of the association visual cortex runs through what portion of the brain?

A

inferior temporal cortex

23
Q

The ventral stream of the association visual cortex is responsible for what type of processing?

A

what?

24
Q

What is a homonymous defect?

A

either right or left visual field affected

25
Q

Where is a homonymous defect usually located?

A

almost exclusively after the optic chiasm

26
Q

Where is a heteronymous defect usually located?

A

almost exclusively at the optic chiasm

27
Q

What is a heteronymous defect?

A

involves parts of both visual fields