Photoreception

Question 1

function of the eye

Answer 1

to focus light onto photoreceptors found at the retina in the back of the eye

Question 2

Sclera
-what is it
function (2)

Answer 2

-thick white outer layer
-protection and shape

Question 3

Cornea
-what is it
-what does the tissue need and how does it get it

Answer 3

window to the eye, front of sclera
tissue needs dissolved o2 which it gets from the aqueous humour

Question 4

choroid
-what is it
-what does it contain and why

Answer 4

underneath the sclera
contains blood vessles to supply the choroid with oxygen and nutrients and pigmented granules to create a black interior and prevent light from bouncing inside the eye

Question 5

iris
-what does it contain and its function

Answer 5

thin muscles to constrict/dialate pupil

Question 6

pupil, opening of the eye
-why is it black
-what determines its size and what is it called
-what influences constriction and dilation

Answer 6

-because of dark choroid layer
-the iris, light adaptation and pupillary reflex
-the symaphtetic and parasympathetic nervous systems

Question 7

lens
-what shape is it and where is it located
-what does it do

Answer 7

-bioconvex, behind the iris
-it refracts light and produces an inverted iamge on the retina

Question 8

Retina- what is it
-what 3 layers
-what do rods and cones do
-what is the blind spot

Answer 8

innermost layer of the eye, tissue
-ganglion, bipolar, photoreceptors
-rods and cones convert light energy into nerve impulses and seend it to the optic nerve and brain
-the blind spot is where optic nerve exists and there are no photorecepotrs here, so no images can be produced

Question 9

Rods
-what intesity light
-how many rods connect to a bipolar cell/nerve and what does that mean
-what pigment do rods contain and what is it made up of
-what happens to the pigment if its dark, dim, or bright

Answer 9

-low
-multiple connects, meaning not very detailed
-rhodopsin which contains vitamin A (protein opsin and retinal)
-if its too dark, rhodopsin stimulates relwase of hibhibotry neurons which prevent impulses, if its dim, rhodopsin splits and stops the release of them, if too bright, it breaks down too quickly

Question 10

Cones
-what intensity light
-3 types of cones
-how many rods connect to a bipolar/nerve
-where are cones concentrated

Answer 10

-high
-rgb
-one, better detail
-fovea centralis which is righ t behind the pupil and most light rays fall here

Question 11

What does binocular vision mean and why do we have it

Answer 11

it means that our left and right sides of the brain recieve information from the opposite eye, and this makes processing quicker