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Flashcards in Visual System Deck (19):
1

The lateral geniculate nucleus projects to which lobe?

Occipital

2

The ophthalmic artery is a branch of which vessel?

ICA

3

Sudden onset of complete monocular blindness is the consequence of what sort of lesion?

Optic nerve (on affected side)

4

Inferior optic radiations are responsible for what part of the visual field?

Superior quarters

5

What are the 3 key feature sod the accommodation reflex?

1. Lens thickening
2. Convergeance
3. Pupil constriction

6

In which part of the retina are cone cells particularly dense?

The fovea of the macula

7

What are the 3 layers of the retina?

1. Choroid
2. Pigmented layer
3. Neural layer

8

Within which layer of the retina are photoreceptor cells found?

Neural layer

9

What is special about the optic disc (in terms of content) ?

No photoreceptor cells at all!

10

What is the "blind spot"?

It refers to the optic disc. Indeed, there are no photoreceptor cells at the optic disc, it is the point where optic nerve leaves.

11

What are rod cells responsible for?

Black and white vision, low levels lighting vision

12

What are cone cells responsible for?

colour and high definition (= central vision)

13

What are the lateral geniculate nuclei?

They are relay point between optic tracts and visual cortex

14

What is macular sparing?

Central vision is preserved

15

What sort of pathology is macular sparing a feature of?

Vascular damage to the occipital lobe.
Occipital lobe has dual blood supply, posterior cerebral artery for most but middle cerebral for occipital pole.
Occipital pole is responsible for macular vision, and therefore if PCA is affected can lose all vision except macula supplied by MCA.

16

Which nerve is responsible for the afferent limb of the accommodation reflex?

CN II optic

17

Which nerve is responsible for the efferent limb of the accommodation reflex?

CN III occulomotor

18

Which nerve is responsible for the afferent limb of the corneal reflex?

Ophtalmic branch of trigeminal nerve CN V

19

Which nerve is responsible for the efferent branch of the corneal reflex?

Facial nerve CN VII