Highlighted content chapter 11

Question 1

A tumor on the what part of the brain can press on the optic chiasm?

Answer 1

Pituitary

Question 2

A tumor on the pituitary can press on the optic chiasm and cause what kind of field defects?

Answer 2

Bilateral temporal (aka bitemporal hemianopia)

Question 3

How would you describe the orientation of the image on the retina?

Answer 3

Inverted and reversed

Question 4

Information from the lower visual field is projected on the ___________ retina

Answer 4

upper

Question 5

Why are images reversed on the retina?

Answer 5

The right visual field projects onto the left retina (and vice versa) of each eye

Question 6

Why are images inverted on the retina?

Answer 6

Information from the upper visual field is projected onto the lower retina, and vice versa

Question 7

The central fixation point for each eye is what?

Answer 7

The fovea

Question 8

Where do fibers that carry visual information cross?

Answer 8

Optic chiasm

Question 9

True or false: There is a total crossing of fibers in the optic chiasm

Answer 9

False; it’s a partial crossing of fibers

Question 10

Lesions anterior to the [optic] chiasm produce what kind of visual field defects?

Answer 10

monocular

Question 11

Lesions of the optic chiasm produce what kind of visual field defects?

Answer 11

bilateral lateral

Question 12

The medial (nasal) fibers from both eyes do what in the optic chiasm?

Answer 12

Cross over

Question 13

The optic tract wraps around the midbrain, then to where?

Answer 13

The lateral geniculate nuclei (LGN) of the thalamus

Question 14

Where does the optic tract go after the optic chiasm?

Answer 14

The LGN of the thalamus

Question 15

What can result in bitemporal hemianopia from compression of the optic chiasm?

Answer 15

Pituitary adenomas

Question 16

Why do pituitary adenomas cause the visual effect they do?

Answer 16

They press on the optic chiasm, compressing the medial fibers, which convey the outer half of vision for both eyes

Question 17

What is the superior colliculus important in?

Answer 17

Directing visual attention and eye movements towards visual stimuli

Question 18

1) The superior colliculus and pretectal areas project where for visual attention?
2) How?

Answer 18

1) To the brainstem and association cortex
2) Via relays in other thalamic nuclei

Question 19

What are the functions of the other thalamic nuclei that project the superior colliculus to the brainstem?

Answer 19

Visual attention/orientation/discrimination/perception (i.e. help us direct our attention to something seen or heard)

Question 20

What do the neurons of the LGN do?

Answer 20

Participate in motion, spatial awareness, and color vision.

Question 21

What fans out over a wide area to form the optic radiations?

Answer 21

The superior colliculi

Question 22

What pathway is likely defective if color vision isn’t working?

Answer 22

The LGN

Question 23

Central __________________ occlusion can cause infarction of the entire retina

Answer 23

retinal artery

Question 24

Define Amaurosis Fugax

Answer 24

Transient occlusion of the retinal artery

Question 25

1) What causes Amaurosis Fugax?
2) What is a common cause of that?

Answer 25

1) Emboli [occluding the retinal artery]
2) Ipsilateral carotid artery stenosis

Question 26

If a patient describes having the visual of a window shade going up or down in one eye, what might they be having?

Answer 26

Amaurosis Fugax

Question 27

What are the two main symptoms of Amaurosis Fugax?

Answer 27

1) A “window shade going up or down” on ONE eye
2) Loss of vision in one eye for roughly 10 min.

Question 28

What can Amaurosis Fugax be a signal of?

Answer 28

Impending retinal or cerebral infarct.

Question 29

1) What is optic neuritis?
2) What does it cause?

Answer 29

1) A demyelinating disorder of the optic nerve related to MS
2) Eye pain with movement (among other things) of one eye

Question 30

_____ or more of patients with a clinically isolated episode of optic neuritis will eventually develop MS

Answer 30

50%

Question 31

If a patient complains of pain in one eye that’s worse with movement, what may they have?

Answer 31

Optic neuritis