Visual Pathway

Question 1

The visual field of each eye is separated into…

Answer 1

Four quadrants:
Upper & Lower
Right & Left (nasal & temporal)

Question 2

The retina receives…

Answer 2

Visual field projection

Question 3

In the retina, the image is…

Answer 3

Crossed & inverted

Question 4

The temporal 1/2 of the visual field projects to the ____ of the retina

Answer 4

Nasal 1/2

Question 5

The nasal 1/2 of the visual field projects to the _____ of the retina

Answer 5

Temporal 1/2

Question 6

The upper 1/2 of the visual field projects to the ____ of the retina

Answer 6

Lower 1/2

Question 7

The lower 1/2 of the visual field projects to the ____ of the retina

Answer 7

Upper 1/2

Question 8

In the optic chasm, fibers partially cross so that the left 1/2s of the visual field enter the ____ optic tract, and the right 1/2s of the visual field enter the ____ optic tract

Answer 8

Right
Left

Question 9

The optic tracts synapse in the ____

Answer 9

Lateral geniculate nuclei

Question 10

Fibers from the lateral geniculate nuclei form the ____

Answer 10

Optic radiation

Question 11

The optic radiation fibers that correspond to the upper 1/2 of the visual field form the _____ in the ____ lobe

Answer 11

Loop of Meyer
Temporal

Question 12

The optic radiation fibers that correspond to the lower 1/2 of the visual field form the ____

Answer 12

Parietal lobe optic radiation

Question 13

The optic radiation from the loop of Meyer terminate at the ____, carrying visual information from the ____ visual field

Answer 13

Lingual gyrus
Upper

Question 14

The optic radiation fibers from the parietal lobe terminate in the ____, carrying visual information from the ____ visual field

Answer 14

Cuneus
Lower

Question 15

Lesion of right optic nerve

Answer 15

Right anopsia
(Loss of vision in right eye only)

Question 16

Pituitary tumour affecting the optic chiasm (saggital)

Answer 16

Bitemporal hemianopsia
(Loss of peripheral/temporal vision)

Question 17

Right carotid aneurysm affecting the optic chiasm (horizontal)

Answer 17

Right nasal hemianopsia

Question 18

Lesion of right optic tract/LGB/optic radiation/visual cortex

Answer 18

left homonymous hemianopsia
(loss of vision of left visual field)

Question 19

Lesion of right visual cortex (cuneus & lingual) excluding occipital pole

Answer 19

Left homonymous hemianopsia with sparing of macula
(loss of vision of left visual field, sparing central vision)

Question 20

lesion of right parietal lobe optic radiation/cuneus

Answer 20

left homonymous lower quadrantanopsia
(loss of vision of lower left quadrant visual field)

Question 21

lesion of right cuneus excluding occipital pole

Answer 21

left homonymous lower quadrantanopsia with sparing of macula
(loss of vision of lower left quadrant visual field, sparing central vision)

Question 22

lesion of right loop of Meyer/temporal lobe optic radiation

Answer 22

left homonymous upper quadrantanopsia
(loss of vision of upper left quadrant visual field)

Question 23

bilateral internal carotid aneurism affecting optic chiasm (horizontal)

Answer 23

binasal anopsia

Question 24

lesion of right lingual gyrus excluding occipital pole

Answer 24

left homonymous upper quadrantanopsia with sparing of macula
(loss of vision of upper left quadrant visual field, sparing central vision)

Question 25

activation of the light reflex causes...

Answer 25

constriction of pupils (sphincter pupillae mm)

Question 26

what is the accommodation reflex?

Answer 26

convergence, thickening of lens & pupillary constriction

Question 27

light entering the right eye will cause...

Answer 27

direct right pupil constriction indirect left pupil constriction

Question 28

light entering the left eye will cause...

Answer 28

direct left pupil constriction indirect right pupil constriction

Question 29

what happens when light enters the right eye with a lesion of the right optic nerve?

Answer 29

no pupil constriction

Question 30

what happens when light enters the left eye with a lesion of the right optic nerve?

Answer 30

bilateral pupil constriction

Question 31

what happens when light enters the right eye with a lesion of the right oculomotor nerve?

Answer 31

- right pupil cannot constrict (mydriasis) - left pupil constricts

Question 32

what happens when light enters the left eye with a lesion of the right oculomotor nerve?

Answer 32

- right pupil cannot constrict (mydriasis) - left pupil constricts

Question 33

what is Argyle Robertson Pupil?

Answer 33

mydriasis without cycloplegia (**A**ccommodation **R**eflex **P**resent, **L**ight **R**eflex **A**bsent)

Question 34

In the primary visual cortex, what structure separates the upper and lower visual fields?

Answer 34

calcarine sulcus

Question 35

describe the pathway of the light reflex

Answer 35

LIGHT -> retina -> CN II -> optic tract -> sup. brachium --< pretectal nucleus (bilateral; sup colliculi) --< edinger-wesphal nuclei -> CN III --< ciliary ganglion -> short ciliary n --< sphincter pupillae mm

Question 36

describe the pathway of the accommodation reflex

Answer 36

retina -> CN II -> optic tract --< LGB -> optic radiation --< visual cortex -> frontal eye field (8) -> corticobulbar tract --< pretectal nuclei (bilateral; sup colliculi) --< edinger-westphal nuclei -> CN III --< ciliary ganglion -> short ciliary nn --< ciliaris (lens) & sphincter pupillae (constriction) mm

Question 37

what are saccadic movements (saccades)?

Answer 37

high velocity eye movements that orient the eyes toward a stimulus

Question 38

what are the combined functions of the superior colliculus and frontal eye field related to saccadic movements?

Answer 38

coordinate visual, somatic, and auditory info, adjusting movements of the head to the stimulus

Question 39

what are the functions of the superior colliculus related to saccadic movements?

Answer 39

receives info about motion in the visual field and is concerned with visual attentiveness and identification of **broad outlines** of objects

Question 40

what are the functions of the frontal eye field related to saccadic movements?

Answer 40

receives info from primary visual cortex and is concerned with **fine visual discrimination** and saccadic movements to complex visual stimuli