Co-Ordination And Control (The Eye)

Question 1

Function of the Conjunctiva

Answer 1

Prevents foreign bodies entering eye

Question 2

Function of the sclera

Answer 2

Protects the eyeball against mechanical damage

Question 3

Function if the cornea

Answer 3

Allows passage of light, while refracting it

Question 4

Function of the iris

Answer 4

Controls the amount of light entering the eye by controlling the size of the pupil

Question 5

Function of the pupil

Answer 5

Allows light to enter the eye

Question 6

Function if the aqueous humour

Answer 6

Maintains the shape of the front chamber

Question 7

Function of the lens

Answer 7

Adjust the focusing of light on the retina

Question 8

Function of ciliary body

Answer 8

Control the shape of the lens

Question 9

Functions of the suspensory ligaments

Answer 9

Makes the lens thinner

Question 10

Function do the vitreous humour

Answer 10

Maintains the shape of the rear chamber and supports the lens

Question 11

Function of the retina

Answer 11

Initiate impulse in associated neuorines

Question 12

Function do the fovea

Answer 12

Allows colour vision

Question 13

Function of the choroid

Answer 13

Prevents reflection of light in the eyeball

Question 14

Function do optic nerve

Answer 14

Transmits impulses from the retinue to the brain

Question 15

What is the blind spot in the eye?

Answer 15

A region which isn’t sensitive to light.

Question 16

What happens to the iris and control of pupil diameter in bright light?

Answer 16

Circular muscles contract
Radical muscle relax
Iris widens
Pupil constricts
Therefore less light entering the eye

Question 17

What happens to the iris and control of pupil diameter in dim light?

Answer 17

Circular muscles relax
Radical muscles contract
Iris narrows
Pupils dilates
Therefore, more light entering eye.

Question 18

What happens to the lens and the accommodation of light with a distant object?

Answer 18

Light entering is virtually parallel and requires little refraction
Ciliary muscles relax
Suspensory ligaments are taut
Lens is long and thin
Light refracted less

Question 19

What happens to the lens and the accommodation of light with a near object?

Answer 19

Light entering is diverging and requires more refraction
Ciliary muscles contract
Suspensory ligaments slacken
Lens is short and thick
Light refracted more

Question 20

Structure of cone cells in the retina

Answer 20

Cones synapse with a single bipolar neurone, which synapses with one ganglion cell.

Question 21

Structure of rod cells in the retina

Answer 21

Many rods synapse with each bipolar neurone and many bipolar neurones connect with each ganglion cell. This is called retinal convergence.

Question 22

What is the purpose of the choroid layer?

Answer 22

Contains cells with a black pigment (melanin) which absorbs light rays, preventing them from being reflected back through the rods and cones and causing ‘fuzzy’ vision.

Question 23

What are the different properties of the eye?

Answer 23

Sensitivity
Acuity
Colour discrimination