The Eye

Question 1

What do photoreceptors convert light energy into

Answer 1

neural activity

Question 2

what is the pupil

Answer 2

the opening where light enters the eye

Question 3

what is the optic nerve

Answer 3

bundle of axons from the retina

Question 4

what is myopia

Answer 4

near-sightedness

Question 5

what is hyperopia

Answer 5

far-sightedness

Question 6

what is visual acuity

Answer 6

ability to distinguish between two points

Question 7

what is the visual field

Answer 7

amount of space viewed by retina when the eye is fixated straight ahead

Question 8

what is the visual angle

Answer 8

distance across the retina described in degrees

Question 9

microscopic anatomy of the retina?

Answer 9

photoreceptors to bipolar cells to ganglion cells

Question 10

retinal processing is also influenced by _________

Answer 10

lateral connections

Question 11

which cells laterally connect photoreceptors and bipolar cells?

Answer 11

horizontal cells

Question 12

which cells laterally connect bipolar and ganglion cells?

Answer 12

amacrine cells

Question 13

what are the regions of the photoreceptors?

Answer 13

outer segment, inner segment, cell body, synaptic terminal

Question 14

what are the two types of photoreceptors?

Answer 14

rods and cones

Question 15

which photoreceptor has more disks

Answer 15

rods

Question 16

which photoreceptor is LESS sensitive to light

Answer 16

cones

Question 17

what is duplex retina

Answer 17

having both rods and cones

Question 18

what is the relative structure peripheral retina?

Answer 18

more rods than cones + more photoreceptors than ganglion cells

Question 19

at what point is visual acuity maximized?

Answer 19

fovea

Question 20

which photoreceptors are in central fovea?

Answer 20

cones only

Question 21

Light energy interacts with photopigment to produce a change in ________

Answer 21

membrane potential

Question 22

GPCR causes a change in _______

Answer 22

second messenger

Question 23

rod outer segments are depolarized in the dark because of

Answer 23

steady influx of Na+

Question 24

Why does the sodium channel close in response to light?

Answer 24

the cGMP that gates it is converted to GMP by phosphodiesterase

Question 25

How is phosphodiesterase activated in response to light?

Answer 25

Rhodopsin activates transducin which activates phosphodiesterase

Question 26

which opsin has the longest wavelength? (560)

Answer 26

Red

Question 27

what is the receptive field?

Answer 27

the area of retina where light changes neuron's firing rate

Question 28

phototransduction parallels _________

Answer 28

olfactory transduction: electrical to chemical to electrical signal

Question 29

is the mapping of visual space onto retina cells uniform?

Answer 29

No, there are 97 mill photoreceptors to 1 mill RGCs

Question 30

What theory explains our perception of color?

Answer 30

Young-Hemholtz trichromacy theory of color vision

Question 31

Where is the cell body of the ipRGC located?

Answer 31

in the ganglion cell layer of the retina instead of the outer nuclear layer with the rods and cones

Question 32

What is the communication difference b/w ipRGCs vs rods and cones

Answer 32

don't need bipolar cells to communicate? unclear