The iris reflex - Eye

Question 1

What is the danger of bright light

Answer 1

damage to retina

Question 2

What does the iris reflex control

Answer 2

the size of your pupil

Question 3

What happens to pupil size in bright light conditions and WHY

+What is the name of the pupil now

Answer 3

Decrease in size to let less light in and prevent damage

constricted pupil

Question 4

What happens to pupil size in low light conditions and WHY

+ What is the name of the pupil now

Answer 4

increase in size to let more light in so we get more image of surroundings

Dilated pupil

Question 5

What is the iris made up of to control size of pupil

Answer 5

it has two muscles called
circular muscles closest to pupil
radial muscles which are straight and on the outside

Question 6

What happens to muscles when there is bright light

Answer 6

so the pupil needs to get smaller
therefore circular muscles contract to push pupil size down
and radial muscles relax

Question 7

What happens to muscles when there is low light

Answer 7

so pupil needs to get bigger
therefore circular muscles relax and
radial muscles contract and pull outwards to increase pupil size