CB2 /

Question 1

The central nervous system

Answer 1

The central nervous system consists of the brain and spinal cord. It controls the body’s response to a stimulus

Question 2

The peripheral nervous system

Answer 2

The peripheral nervous system connects the sense organs to the central nervous system using nerves

Question 3

The nervous system pathway

Answer 3

Stimulus 
Receptor cells
Sensory neurone
CNS
Motor neurone
Effector 
Response (muscle or gland)

Question 4

What are reflex actions?

Answer 4

Reflex actions are rapid, automatic responses that bypass the brain - they help protect us from injury
E.g. dropping hot objects quickly to prevent yourself from getting burnt

Question 5

Synapse

Answer 5

• The connection between two neurones is called a synapse
• The nerve signal is transferred by chemicals called neurotransmitters, which diffuse (move) across the gap.
• The neurotransmitters then set off a new electrical signal in the next neurone

Question 6

Role of the myelin sheath

Answer 6

• It speeds up the nerve impulse as it travels along the axon
• It insulates the electrical message

Question 7

What happens in between a neurone?

Step 1

Answer 7

The electrical impulse reaches the end of the neurone

Question 8

What happens in between a neurone?

Step 2

Answer 8

This causes a chemical/neurotransmitter to be released

Question 9

What happens in between a neurone?

Step 3

Answer 9

The chemical/neurotransmitter diffuses across the synapse

Question 10

How do you know what a motor neurone is?

Answer 10

The impulse is being sent to the effector

Question 10

How do you know what a sensory neurone is?

Answer 10

The impulse is being sent away from the receptor cells to the brain