The Body

Question 1

What does the retina contain?

Answer 1

Light receptors, sensitive to different colours

Question 2

What is binocular vision?

Answer 2

It judges distance by comparing images from each eye, the more different they are, the nearer the object

Question 3

What is accommodation?

Answer 3

Altering the shape of the lens to focus light from objects

Question 4

Do the ciliary muscles relax or contract to focus on distant objects?

Answer 4

The muscles relax, and the suspensory ligaments tighten, making the lens flatter

Question 5

To focus on near objects, does the lens need to be fat or thin?

Answer 5

Fatter, because the ciliary muscles contract and the suspensory ligaments slacken

Question 6

When the lens has a thin shape, where is the eye trying to focus?

Answer 6

Distant objects

Question 7

What do the suspensory ligaments do?

Answer 7

Alter the shape of the lens when focusing

Question 8

What do ciliary muscles do?

Answer 8

Control suspensory ligaments

Question 9

What causes red-green colour blindness?

Answer 9

Lack of specialised cells in the retina

Question 10

What are long and short sight caused by?

Answer 10

The eyeball or lens being the wrong shape

Question 11

In long sight, is the eyeball too short or too long?

Answer 11

Too short

Question 12

In long sight, is the lens too thin or too fat?

Answer 12

Too thin

Question 13

What does a too short eyeball and a too thin lens cause?

Answer 13

Long sight

Question 14

In long sight, where is the image focused?

Answer 14

Behind the retina

Question 15

In short sight, is the eyeball too long or too thin?

Answer 15

Too long

Question 16

When the lens is too fat, where is the image focused?

Answer 16

In front of the retina

Question 17

How can you correct long or short sight?

Answer 17

Corneal surgery or glasses

Question 18

What kind of lens can correct long sight?

Answer 18

A convex lens

Question 19

What kind of lens is used to correct short sight?

Answer 19

Concave

Question 20

What are nerve cells called?

Answer 20

Neurones

Question 21

Where do nerve impulses pass along?

Answer 21

The axon

Question 22

How are impulses picked up?

Answer 22

Neurones are adapted to have long branched endings

Question 23

What is the gap between neurones called?

Answer 23

A synapse

Question 24

How are light rays changed by the cornea and the lens?

Answer 24

They are refracted (bent)

Question 25

The gap between neurones is a synapse- what does the arrival of an impulse trigger?

Answer 25

A transmitter substance

Question 26

What is a stimulus?

Answer 26

A change in the environment around you

Question 27

What are receptors?

Answer 27

Groups of cells which are sensitive to a stimulus

Question 28

What do receptors do?

Answer 28

These change stimulus energy into electrical impulses that travel through neurones

Question 29

Give an example of a stimulus?

Answer 29

``` Light Sound Touch Pressure Pain Chemical Position Temperature ```

Question 30

What kind of receptors do your eyes have?

Answer 30

Light receptors, these are just like any animal cells. With a nucleus, cytoplasm and cell membrane.

Question 31

What kind of receptors do your ears have?

Answer 31

Sound receptors and balance receptors

Question 32

What kind of receptors does your nose have?

Answer 32

Smell receptors, sensitive to chemical stimuli

Question 33

What kind of receptors does your tongue have?

Answer 33

Taste receptors

Question 34

What kind of receptors does your skin have?

Answer 34

Sensitive to touch, pressure, pain and temperature change.

Question 35

What are sensory neurones?

Answer 35

These carry electrical impulses from receptors to the central nervous system.

Question 36

What are relay neurones?

Answer 36

Nerve cells that carry signals from the sensory neurones to motor neurones

Question 37

What are motor neurones?

Answer 37

Nerve cells that carry signals from the central nervous system to muscles or glands

Question 38

What is the central nervous system?

Answer 38

It's where all the information is sent and where all reflexes and actions are coordinated

Question 39

What does the central nervous system consist of?

Answer 39

The brain and spinal cord

Question 40

What do neurones do?

Answer 40

Transmit information as electrical impulses to and from the central nervous system

Question 41

Where are "instructions" from the central nervous system sent to?

Answer 41

The effectors, eg muscles and glands

Question 42

What do glands do in response to a nervous impulse?

Answer 42

Secrete hormones

Question 43

What do muscles do in response to a nervous impulse?

Answer 43

Contract

Question 44

What is the connection between two neurones called?

Answer 44

A synapse

Question 45

What is the nerve signal transferred by?

Answer 45

Chemicals

Question 46

How do nerve signals move across the synapse?( the gap)

Answer 46

They diffuse

Question 47

What are reflexes?

Answer 47

Automatic responses to certain stimuli

Question 48

Why do we have reflexes?

Answer 48

To stop us being injured

Question 49

What is the passage of information in a reflex called?

Answer 49

A reflex arc

Question 50

Where do the neurones travel in a reflex arc?

Answer 50

Through the spinal cord or through an unconscious part of the brain

Question 51

What are hormones?

Answer 51

Chemicals released directly into the blood