1. Which of the following are components of the Central Nervous System (CNS)?

2. The diagram shows a sensory neurone. Identify the structure labeled X.

3. Which structure is part of the Peripheral Nervous System (PNS)?

4. Where are receptor cells located?

5. Which of these are effector organs?

6. State the type of signal that travels along neurones. [2 marks]

7. Describe the function of the CNS. [2 marks]

8. Explain the role of sensory neurones in the nervous system. [2 marks]

9. Define the term 'reflex action'. [2 marks]

10. Explain the importance of reflex actions. [2 marks]

11. Compare the position of the cell body in a sensory neurone with that in a motor neurone.
[2 marks]

Sensory neurone cell body position:

Motor neurone cell body position:

13. Compare the length of the axon in sensory and motor neurones. [2 marks]

14. Explain why neurones have a myelin sheath. [2 marks]

15. Describe the structure and function of a synapse. [2 marks]