CN II

Question 1

Where does the optic canal emerge from? What is its route?

Answer 1

the posterior aspect of the eyeball. It then exits through the roof of the orbit through the optic canal to enter the middle cranial fossa where it meets with the other eye to form the optic chiasm.

Question 2

What is the optic chiasm surrounded by? (2)

Answer 2

1. The pituitary gland lies inferior to the chiasm

2. The internal carotid artery lies lateral to it.

Question 3

Where is the optic tract?

Answer 3

the optic chiasm retinal fibers are rearranged and then exit the chiasm to form the optic tracts that lie posterior to the optic chiasm.

Question 4

The optics nerves are composed of what? Where is it in the structure

Answer 4

axons of retinal ganglion cells

Question 5

Retinal ganglion cells are where?

Answer 5

They form the inner most layer of the cells (nearest the vitreous. And their axon form the optic nerve.

Question 6

The visual pathway carries visual information from? to?

Answer 6

From the retina to the primary visual cortex in the occipital lobes.

Question 7

The first neuron in the visual pathway are?

Answer 7

Retinal ganglion cells

Question 8

What happens to the retinal ganglion cells at the optic chiasm?

Answer 8

The temporal and nasal part take different pathways.

Question 9

The ganglion axons from the nasal retina do what? Enter where? On which side?

Answer 9

they cross in the center of the optic chiasm and enter the optic tract on the opposite side?

Question 10

The ganglion axons on the temporal retina do what? enter where? On which side?

Answer 10

They stay on the same side in the lateral part of the optic chiasm and enter the optic tract on the same side.

Question 11

The second neurons’ cell bodies lie where?

Answer 11

lateral geniculate nucleus

Question 12

The second neurons: Where do the axons travel through? Terminate where? Lying next to what?

Answer 12

They travel through the brain as the optic radiations and terminate in the visual cortex, adjacent to the calcarine fissure of the occipital lobe.

Question 13

LGN axons carrying information from the superior retina travel through what? To what?

Answer 13

Carry information from superior retina and travel through the parietal lobe and terminate in the cuneus of the occipital lobe.

Question 14

LGN axons carrying information from the inferior retina travel through what? To what?

Answer 14

Travel from the temporal lobe and terminate in the lingual gyrus of the occipital lobe.

Question 15

Nasal retina sees the ____________ of the visual world.

Answer 15

temporal half

Question 16

temporal retina sees the __________ of the visual world

Answer 16

nasal half

Question 17

superior retina sees the _______of the visual world

Answer 17

inferior part

Question 18

Inferior retina sees the ___________ of the visual world.

Answer 18

superior

Question 19

Enlargement of the pituitary gland due to a tumor would push upward and first compress the ________. From which eyes?

This would result in?

Answer 19

centrally located inferior nasal fibers from both eyes.

superior temporal visual field loss.

Question 20

As the pituitary gland continues to enlarge superiorly the ________will eventually be involved, leading to a complete __________ visual field defect.

Answer 20

superior nasal fibers

Bi-temporal visual field defect

Question 21

An aneurysm in the right ICA would compress the ______ ______ fibers in the optic chiasm.

This would lead to ________ visual field loss in the right eye.

Answer 21

right temporal

nasal