The Nervous System

Question 1

What is the function of the nervous system?

Answer 1

It allows you to react to what goes on around you

Question 2

What is a stimulus?

Answer 2

A change in your environment which you may need to react to

Question 3

What are the 5 sense organs?

Answer 3

1. Eyes
2. Ears
3. Nose
4. Tongue
5. Skin

Question 4

What are receptors?

Answer 4

A group of cells which are sensitive to stimulus. They change stimulus energy into electrical impulses

Question 5

Name examples of a stimulus

Answer 5

Light, sound, touch, pressure, chemical, change in position or temperature

Question 6

Name the receptors for each sense organ

Answer 6

Eye- light receptors
Ears- sound receptors, sensitive to change in position
Nose- smell receptors , sensitive to chemical stimuli
Skin- touch, pressure and temperature change
Tongue - taste receptors, chemical stimuli

Question 7

What are the job of sensory neurones?

Answer 7

These are the nerve cells that carry signals as electrical impulses from the receptions in the sense organs to the central nervous system

Question 8

What are relay neurones?

Answer 8

The nerve cells that carry signals from sensory neurones to motor neurones

Question 9

What are motor neurones?

Answer 9

The nerve cells that carry signals from the CNS to the effector muscles or glands

Question 10

What are effectors?

Answer 10

Muscles and glands that respond in different ways. Muscles contract in response to a nerve impulse and glands secrete hormones

Question 11

What does the CNS consist of?

Answer 11

The brain and spinal chord

Question 12

What is the job of neurones?

Answer 12

To send information very quickly to and from the CNS

Question 13

What is the connection between two neurones?

Answer 13

A synapse

Question 14

How is a nerve single transferred across a synapse ?

Answer 14

By chemicals which diffuse across the gap

Question 15

What do the chemicals in a synapse do?

Answer 15

The chemicals set off a new electrical signal in the next neurone

Question 16

What is a reflex ?

Answer 16

An automatic response to a stimuli - they reduce the chances of being injured

Question 17

What is a reflex arc?

Answer 17

The passage of information in a reflex from receptor to effector

Question 18

Where do the neurones in a reflex arc travel?

Answer 18

Through the spinal chord or an unconscious part of the brain

Question 19

Explain the process of the reflex arc, referring to synapses

Answer 19

After the stimulus has been detected, the impulses reach the synapse between the sensory neurones and a relay neurone and they trigger chemicals to be relatedness these chemicals cause impulses to be sent along the relay neurone. The impulses reach a synapse between the relay and motor neurone and the same thing happens. Impulses are sent along the motor neurone

Question 20

State the block diagram of a reflex arc

Answer 20

Stimulus - receptor - sensory neurone - relay neurone - motor neurone - effector - response

Question 21

What are hormones?

Answer 21

Hormones are chemical messengers which travel in the blood to activate target cells

Question 22

How are hormones carried?

Answer 22

They are carried in the blood plasma to other parts of the body

Question 23

What do hormones control?

Answer 23

Things in organs and cells that need constant adjustment

Question 24

What does the pituitary gland produce?

Answer 24

FSH and LH

Question 25

What do the ovaries produce?

Answer 25

Oestrogen

Question 26

What are the differences between nerves and hormones?

Answer 26

Nerves carry fast messages, hormones are slower
Nerves act for a very short time, hormones have long lasting effects
Nerves act on a very precise area, hormones act in a more general way