Human Eye

Question 1

Cornea

Answer 1

Protection and focusing of light

Question 2

Iris

Answer 2

Circular muscle that can open and close to allow more or less light in

Question 3

Aqueous humour

Answer 3

Fluid that retains the eyes shape

Question 4

Lens

Answer 4

Attached to muscles and focuses light

Question 5

Conjunctiva

Answer 5

Protective layer

Question 6

Retina

Answer 6

Contains light sensitive cells rods and cones

Question 7

Optic nerve

Answer 7

Goes to the brain

Question 8

Sdera

Answer 8

Protective coat surrounding eye

Question 9

Cone cells

Answer 9

Pick up different wavelengths of light
Doesn’t work in low light intensities
Each cone cells is connected to its own bipolar/ sensory neuron for better visual acuity than rods

Question 10

Cone cells: what light sensitive pigment does it contain

Answer 10

Iodopsin sensitive to either red blue or yellow light

Question 11

Rod cells

Answer 11

Pick up varying intensifies of light
Sensitive at low intensities but not colour
Several rod cells on one sensory neuron

Question 12

Rod cells: what light sensitive pigment does it contain?

Answer 12

Rhodopsin

Question 13

How do rod cells produce impulses?

Answer 13

Rhodopsin is cis retinal and Opsin
Bleaching in low light intensity
Trans retinal and opsin- trans can’t bind to opsin
Opsin changes the permeablility of rod cell to sodium
Sodium channels close
Less diffuse so interior is more negative
Generator potential
If threshold is reached nt released into the synapse with bipolar cell

Question 14

Dark adapted light adapted

Answer 14

After 30 mins in darkness rhodopsin is fully reformed- eye is sensitive to dim light and is dark adapted