The Eye

Question 1

What is the sclera

Answer 1

Tough outer coat. Visible white part of the eye.

Question 2

What is the choroid layer

Answer 2

Middle layer of eyeball. Deeply pigmented to absorb light and prevent internal reflection. Contains lots of blood vessels.

Question 3

What is the retina

Answer 3

Innermost layer in eye. Contains many rods and cones + fibre nerves.

Question 4

What is the optic nerve

Answer 4

Carries nerve impulses from the retina directly.

Question 5

What is the fovea (yellow spot)

Answer 5

Part of the retina where cones are concentrated these enables us to see colours in bright light

Question 6

What is the conjunctiva

Answer 6

Transparent layer the protects cornea

Question 7

What is the cornea

Answer 7

Transparent window at front of eye. Allows light to pass through

Question 8

What is the iris

Answer 8

Coloured ring of tissue behind cornea. Controls amount of light entering the eye by changing size of pupil.

Question 9

What is the pupil

Answer 9

Hole in centre of iris - size is controlled by radial and circular muscles of iris

Question 10

What is the ciliary body/ciliary muscle

Answer 10

Contains muscles which can contact or relax to change thickness of lens

Question 11

What is the suspensory ligament

Answer 11

Hold lens in position

Question 12

What is the lens

Answer 12

Clear part behind the iris that helps to focus light onto the retina. Helps to focus on far and close objects

Question 13

The retina consists of _________ and _________

Answer 13

Rods and cones

Question 14

________ see in dim light

Answer 14

Rods see in dim light

Question 15

________ see in bright light

Answer 15

Cones

Question 16

________ see black and white vision while _________ see colour

Answer 16

Rods Cones

Question 17

_________ are found throughout the retina

Answer 17

Rods

Question 18

___________ are concentrated in the yellow spot

Answer 18

Cones

Question 19

What are the 2 types of muscle around the iris

Answer 19

Circular and Radial

Question 20

When the circular muscle contracts, the pupil gets _____________

Answer 20

Smaller

Question 21

When the radial muscle contracts, the pupil gets ____________

Answer 21

Bigger

Question 22

Name the stimulus that enters the eye and is detected by receptors

Answer 22

Light

Question 23

Which part of the eye contains receptors

Answer 23

Retina

Question 24

How do messages travel from receptors in the eye to the brain

Answer 24

By nerve impulses. Receptor —> Along a sensory neuron (optic nerve)

Question 25

Name 3 sense organs

Answer 25

Tongue, Nose, Ears

Question 26

The _________ consists of circular and radial muscles

Answer 26

Iris

Question 27

The __________ consists of millions of light sensitive cells

Answer 27

Retina

Question 28

The ____________ consists of many blood vessels

Answer 28

Choroid

Question 29

The _________ contains only cones

Answer 29

Yellow spot / Fovea

Question 30

The blind spot has no \_\_\_\_\_\_\_\_\_-sensitive cells

Answer 30

Light-sensitive cells

Question 31

The ligaments hold the \_\_\_\_\_\_\_

Answer 31

Lens

Question 32

The __________ allows light to enter the eye

Answer 32

Pupil

Question 33

The __________ bends the light rays

Answer 33

Cornea

Question 34

The lens can change \_\_\_\_\_\_\_\_\_\_

Answer 34

Shape

Question 35

The optic nerve sends messages to the \_\_\_\_\_\_\_\_\_\_

Answer 35

Brain

Question 36

The rods respond to _______ light

Answer 36

Dim light

Question 37

The cones respond to __________ light

Answer 37

Bright light

Question 38

In bright light the pupil becomes \_\_\_\_\_\_\_\_\_\_\_

Answer 38

Smaller

Question 39

In bright light the __________ muscles relax and the ____________ muscles contract - thus the pupil becomes \_\_\_\_\_\_\_\_\_\_\_

Answer 39

Radial Relax Circular Contracts Smaller

Question 40

If it is bright, then the pupil becoming smaller allows ________ light to fall on the ___________ at the back of the eye

Answer 40

Less Retina

Question 41

What is the job of the iris

Answer 41

Controls the amount of light that falls in the retina

Question 42

Flow diagram to summarise the stages in a spinal reflex

Answer 42

Stimulus ---\> receptor ---\> sensory neurone ---\> relay neuron ---\> motor neuron ---\> effector

Question 43

1

Answer 43

Suspensory Ligament

Question 44

2

Answer 44

Conjunctiva

Question 45

3

Answer 45

Iris

Question 46

4

Answer 46

Pupil

Question 47

5

Answer 47

Cornea

Question 48

6

Answer 48

Ciliary muscle

Question 49

7

Answer 49

Lens

Question 50

8

Answer 50

Retina

Question 51

9

Answer 51

Fovea

Question 52

10

Answer 52

Optic nerve

Question 53

A person moves from a dim room into bright sunshine. Describe the change in the appearence of their pupils.

Answer 53

Their pupils contract to allow less light into the eye

Question 54

In the dark you cannot see colours... Why?

Answer 54

Because in the dark our eyes only use rods which don't see colours. Cones don't respond to dim light therefore they aren't used.