Optic Nerve Visual Pathway and Lesions

Question 1

In the right eye, where does the Temporal Hemiretina receive light rays from?

Answer 1

Left visual field

Question 2

In the right eye, where does the Nasal Hemiretina receive light rays from?

Answer 2

Right visual field

Question 3

In the left eye, where does the Temporal Hemiretina receive light rays from?

Answer 3

Right visual field

Question 4

In the left eye, where does the Nasal Hemiretina receive light rays from?

Answer 4

Left visual field

Question 5

In the right eye, where do the fibers of Temporal Hemiretina travel?

Answer 5

Down the right optic nerve and to the right optic tract (Ipsilateral fibers)

Question 6

In the right eye, where do the fibers of Nasal Hemiretina travel?

Answer 6

Down the right optic nerve, crossing the optic chiasma, and to the left optic tract (Contralateral fibers)

Question 7

In the Left eye, where do the fibers of Temporal Hemiretina travel?

Answer 7

Down the left optic nerve and to the left optic tract (Ipsilateral fibers)

Question 8

In the left eye, where do the fibers of Nasal Hemiretina travel?

Answer 8

Down the left optic nerve, crossing the optic chiasma, and to the right optic tract (Contralateral fibers)

Question 9

What layers of the lateral geniculate bodies do Ipsilateral fibers go to?

Answer 9

2, 3, 5

Question 10

What layers of the lateral geniculate bodies do contralateral fibers go to?

Answer 10

1, 4, 6

Question 11

What are the fibers that run from the lateral geniculate body through the parietal lobe and ending in occipital lobe?

Answer 11

Superior retinal fibers (Barums loop)

Question 12

What are the fibers that run from the lateral geniculate body through the temporal lobe and ending in occipital lobe?

Answer 12

Inferior retinal fibers (Myers loop)

Question 13

What is the primary visual cortex?

Answer 13

Striate cortex

Question 14

Where specifically are the superior and inferior retinal fibers going to?

Answer 14

Striate cortex

Question 15

What happens if you lesion the entire optic nerve on one eye?

Answer 15

You lose all vision in that eye (monocular blindness or anopia)

Question 16

What happens if you lesion the contralateral fibers at the optic chiasma?

Answer 16

Lose vision in both temporal visual fields (Bitemporal hemianopia)

Question 17

What happens if you lesion the ipsilateral fibers or ICA compresses the fibers?

Answer 17

Lose vision in both nasal visual fields (Binasal hemianopia)

Question 18

What happens if you lesion the right optic tract?

Answer 18

You lose vision in the temporal vision field in left eye and the nasal visual field in the right eye (Left homonymous hemianopia)

Question 19

What happens if you lesion the right eye’s Superior Retinal fibers?

Answer 19

You lose vision in the left inferior visual field in both eyes ( Left inferior quadrant hemianopia)

Question 20

What happens if you lesion the left eye’s Inferior retinal fibers?

Answer 20

You lose vision in the right superior visual fields in both eyes (Right superior quadrant hemianopia)

Question 21

What do the superior and inferior retinal fibers make up?

Answer 21

The optic radiations

Question 22

What happens if you damage the right eye’s optic radiation?

Answer 22

You lose vision in the left visual fields in both eyes (Left homonymous hemianopia)

Question 23

What happens if you damage the right occipital lobe?

Answer 23

You lose vision in the left visual fields in both eyes except for the macula (Left homonymous hemianopia with sparing of the macula)

Question 24

How is the macula spared in the occipital lobe when the posterior cerebral artery is occluded?

Answer 24

Due to MCA still supplying the area