t8l4 the eye

Question 1

role of the cornea

Answer 1

refracts light when it enters the eye

Question 2

role of the iris

Answer 2

changes size in response to varying light levels to allow the pupil to contract and dilate

Question 3

role of the lens

Answer 3

focuses light onto the retina

Question 4

role of the retina

Answer 4

contains receptors for detecting light

Question 5

role of the optic nerve

Answer 5

send action potential to brain

Question 6

Name two types of photoreceptros

Answer 6

ROD AND CONE

Question 7

describe the path of light detection in cone cells to the optic nerve

Answer 7

cone cell > bipolar cell > gangolin cell > optic nerve

Question 8

what pigment is in rod cells

Answer 8

rhodopsin

Question 9

what part of rod cells contains rhodopsin

Answer 9

outer segment

Question 10

Describe what happens when light is detected by a rod cell to generate an action potential

Answer 10

In light rhodopsin is converted into retinal and opsin

Sodium ions are being pumped out of cell by KNa pump

Sodium ion channels closed so Na cannot diffuse back in

Hyperpolarisation occurs

No inhibitory neurotransmitter is released

Membrane of bipolar cell depolarises and action potential is generated 8