Visual Tracts

Question 1

What forms the visual pathway?

Answer 1

Axons of ganglion cells from rods and cones

Question 2

Visual field

Answer 2

Area that a person is able to see when both eyes fixed

Question 3

Retinal field

Answer 3

The image on the retina (inverted)

Question 4

Binocular zone

Answer 4

Central region seen by both eyes

Question 5

Monocular zone

Answer 5

Peripheral zone seen only by 1 eye

Question 6

Left half of visual field forms image on:

Answer 6

Nasal half of left retina

Temporal half of right retina

Question 7

Right half of visual field forms image on:

Answer 7

Nasal half on right retina

Temporal half of left retina

Question 8

Nasal half goes:

Answer 8

CL

Question 9

Temporal half goes:

Answer 9

IL

Question 10

Optic tract includes fibers from:

Answer 10

Temporal half of IL eye

Nasal half of CL eye

Question 11

Where do the optic tracts terminate?

Answer 11

Lateral geniculate nucleus

Question 12

Ventral base of LGN is from:

Dorsal and lateral borders of LGN are from:

Answer 12

Ventral base of LGN is from: optic tract (reticulogeniculate)
Dorsal and lateral borders of LGN are from: outgoing optic radiations

Question 13

Magnocellular (M) layers

Answer 13

Layers 1 and 2.
Large cells
Receive info from rods.

Question 14

Parvocellular (P) layers

Answer 14

Layers 3 to 6.
Small cells.
Receive info from cones.

Question 15

Temporal retina stay ____ and terminate in layers:

Answer 15

IL and terminate in layers 2, 3 and 5.

Question 16

Nasal retina goes ____ and terminate in layers:

Answer 16

CL and terminate in layers 1, 4 and 6.

Question 17

Same point in visual space is represented ___ times.

Answer 17

6. One for each layer of LGN. Optic tract branches.

Question 18

What goes from LGN to calcarine sulcus?

Answer 18

Geniculocalcarine (geniculostriate) pathway

Question 19

Lower quadrant of CL hemifields target:

Answer 19

Superior bank of calcarine sulcus, the cuneus.

Question 20

Upper quadrant of CL hemifields target:

Answer 20

Inferior bank of calcarine sulcus, the lingual gyrus.

Question 21

Meyer loop

Answer 21

A U-turn that fibers from the upper quadrant of CL fibers take to get to the lingual gyrus.

Question 22

Where does the visual pathway end?

Answer 22

Striate cortex (Broadmann’s area 17).

Question 23

Visual association cortex is composed of which areas:

Answer 23

Area 18 and 19. PTO area.

Question 24

Superior colliculus is important in:

Answer 24

Directing eye movements

Question 25

Pretectal area is important in:

Answer 25

Pupillary light reflex

Question 26

Hemianopia

Answer 26

Blindness in one half of visual field

Question 27

Homonymous visual field Heteronymous visual field

Answer 27

Homo: visual field losses is similar in both eyes. Hetero: 2 eyes have non-overlapping field losses.

Question 28

Macular sparing

Answer 28

Visual field loss that preserves vision in center of visual field

Question 29

Congruent deficit Incongruent deficit

Answer 29

Deficit is symmetric Deficit is asymmetric

Question 30

Damage anterior to chiasm affects:

Answer 30

Only IL eye

Question 31

Damage at the chiasm causes:

Answer 31

Heteronymous defects

Question 32

Damage posterior to chiasm causes:

Answer 32

Homonymous defects

Question 33

Associative visual agnosia cause: What can/can't they do?

Answer 33

Infarction in left occipital lobe and posterior corpus callosum, usually from occlusion of PCA. Disconnects language area from visual association cortex. Pt cannot name or describe an object, but can recognize/demonstrate its use.