5th Form Definitions And Key Concepts

Question 1

Cornea

Answer 1

-A curved transparent disc at the front of the eye
-Does most of the focusing

Question 2

Pupil

Answer 2

-A circular opening whose size is controlled by the iris (the coloured part of the eye)

Question 3

Iris

Answer 3

-A ring of nucleus with a hole in the middle (pupil)
-Iris controls how much light enters the eye

Question 4

Lens

Answer 4

-Soft, flexible & transparent
-Shape can be changed to fine tune the focusing of light onto the retina.

Question 5

Ciliary muscles

Answer 5

-A ring of muscle at the edge of the eye which circles the lens.
-When it contracts the lens get fatter
-When it relaxes the lens gets thinner

Question 6

Suspensory Ligament

Answer 6

-Strong fibres which attach the lens to the ciliary muscle

Question 7

Retina

Answer 7

-Contains light sensitive cells called rods & cones

Question 8

Fovea

Answer 8

-The region of the retina with the greatest number of cones

Question 9

Optic Nerve

Answer 9

-Consists of many neurons which carry impulses from the retina to the brain

Question 10

Conjuctiva

Answer 10

-A mucous membrane that covers the eye to prevent infection