vision pt 2

Question 1

What is ganglion cells?

Answer 1

Action potential generated

Question 2

What does the ciliary body do?

Answer 2

Produces aqueous humor and controls accommodation to light by changing the shape of the lens

Question 3

Where is the lens located?

Answer 3

Located just behind iris and held in place by ciliary body

Question 4

What is the function of the lens?

Answer 4

Focuses light onto the retina, biconvex, transparent, flexible

Question 5

What is the retina?

Answer 5

Multi-layered sensory tissue that lines the back of the eye

Question 6

What are cones in the retina used for?

Answer 6

Bright light and color vision (5-6 million)

Question 7

What are rods in the retina used for?

Answer 7

Peripheral and night vision (125 million)

Question 8

What is neural layer in the retina?

Answer 8

Continuous to posterior margin of the ciliary body

Question 9

What are the two layers of retina?

Answer 9

Neural and inner layer

Question 10

What is inner layer in the retina?

Answer 10

Extension of the brain

Question 11

What does the optic nerve do?

Answer 11

Transmits electrical impulses from retina to the brain and has optic disc

Question 12

What is the blind spot?

Answer 12

On retina where optic nerves leads back into the brain, lacks photoceptors, no rods or cone cells

Question 13

What are the three different photopigments.

Answer 13

Blue, red, green

Question 14

What is the temporal lobe?

Answer 14

Center for visual learning and recognition by sight

Question 15

What is the midbrain - limbic sector?

Answer 15

Emotional responses to visual stimuli

Question 16

What is the midbrain - superior colliculus?

Answer 16

Guides visual attention

Question 17

What is the cyclic GMP?

Answer 17

In the dark, Na+ channels are held open by a nucleotide

Question 18

What triggers the release of neurotransmitters?

Answer 18

Inflow of sodium

Question 19

Na+> K+ ->

Answer 19

cell depolarization

Question 20

Inhibitory neurotransmitter from photoreceptors to

Answer 20

Glutamate

Question 21

Synapse between photoreceptor and bipolar cell

Answer 21

Continuous low energy flow through bipolar cell tells your brain you’re in the dark

Question 22

Rhodopsin formation

Answer 22

Light -> cis -> trans conformation

Question 23

What is cis?

Answer 23

Bent and lots of energy

Question 24

What is trans?

Answer 24

Straight and low energy released

Question 25

Bleaching separation

Answer 25

Cis and trans

Question 26

What happens when opsin is separated?

Answer 26

Becomes an active enzyme

Question 27

Process of breaking down cGMP

Answer 27

Activates transducin -> activates phosphodiesterase (enzymes)

Question 28

What is bipolar cells?

Answer 28

Process info from photoreceptors

Question 29

What are horizontal cells important for?

Answer 29

Vision

Question 30

What horizontal and amacrine cells?

Answer 30

Integrate information laterally from many cells

Question 31

What is macula lutea?

Answer 31

Lateral to the blind spot and mostly cones

Question 31

What is “filling-in”?

Answer 31

Other eye is compensating for the blind spot

Question 32

What is fovea centralis?

Answer 32

Has a pit and light directly to photoreceptors to enhance visual acuity

Question 33

Increase speed

Answer 33

Less dense

Question 34

Decrease speed

Answer 34

More dense

Question 35

What is convergence?

Answer 35

Up to 100 rods communicate and cause fuzzy vision

Question 36

Where is light bent at?

Answer 36

Cornea and twice at lens

Question 37

What is rhodopsin?

Answer 37

Vitamin A relative and retinal combine with protein (opsins)

Question 38

Opsin red

Answer 38

560 nm - cones

Question 39

Opsin blue

Answer 39

420 nm - cones

Question 40

Opsin green

Answer 40

530 nm - cones