W6_04 Eye: Anatomy and Physiology II

Question 1

fovea is how large in diameter?

Answer 1

1.5mm

Question 2

what 3 characteristics makes resolution high in the fovea?

Answer 2

anatomical structure (ganglion diverts, avascular, only photoreceptors + glial cells);

types of photoreceptors (cones)

ratio of photoreceptors to ganglion cells (1:1 in the fovea)

Question 3

cones are responsible for:

Answer 3

“what”
colour vision
bright light

Question 4

rods are responsible for

Answer 4

“where”
monochromatic
dim light

Question 5

what are drusen?

Answer 5

metabolic debris accumulation at the layer of bruch’s membrane

Question 6

pathology of retinal pigmented epithelium?

Answer 6

macular disease

Question 7

pathology of optic nerve?

Answer 7

glaucoma,
optic neuritis,
ischemia,
inflammation,
compression

Question 8

nuclei along the optical pathway in the brain?

Answer 8

suprachasmatic nucleus of hypothalamus;
lateral geniculate nucleus of thalamus;
pretectal nucleus and E-W nucleus of midbrain

Question 9

visual field loss respecting the horizontal midline suggests lesion is where?

Answer 9

retina/optic nerve lesion;

one or both eyes

Question 10

visual field loss respecting the vertical midline suggests lesion is where?

Answer 10

neurologic lesion;

often both eyes

Question 11

when the knee of von willebrand is lesioned, it produces what kind of visual field defect?

Answer 11

junctional scotoma

Question 12

the fovea takes up which fraction of the tissue around the calcarine fissure?

Answer 12

posterior 1/2