1. Lesson starter What is the central nervous system made up of?
What are the three main areas of the brain and what job does each part do?

2. The brain
The Cerebrum
Controls conscious thought, memory, reasoning and imagination

3. The brain The Cerebellum
Controls balance and co-odination of muscle action

4. The Medulla Oblongata The brain
Controls involuntary actions like heart rate, breathing and digestion

5. Control and Communication
Lesson 2- The journey of the impulse

6. Learning Intention Revise the journey of the impulse
and talk about the different types of neurones

7. Receptors and Effectors
Information is passed through nerves to the CNS in the form of electrical impulses

8. Receptors and Effectors
Our sensory organs detect information from our surroundings
The information is the stimulus which triggers off a nerve impulse.
This impulse is carried along a sensory nerve cell to the C.N.S. where it is processed

9. What are our SENSORY ORGANS?
Sensory organs have RECEPTORS to gather information (stimuli) from the environment
What are our SENSORY ORGANS?

10. Sensory Organs Ears- Detects sounds (hearing)
Skin- detects changes in pressure/
temperature/pain (touch)
Eyes- Detects pictures (sight)
Ears- Detects sounds (hearing)
Tongue- Detects chemicals in food (taste)
Nose- Detects chemicals in the air (smell)

11. Receptors and Effectors
Information is gathered by RECEPTORS (in sensory organs) and sent along a sensory nerve in an electrical impulse.
It is PROCESSED by the CNS
Messages are then sent to along a motor neuron to the EFFECTORS in order to bring about a RESPONSE

12. Effectors
The EFFECTOR will carry out the suitable response to the STIMULI
Muscles- contract and pull on the bones to bring about movement
Glands- Send chemical messages in the form of hormones

13. Neurones Neurone is another name for a NERVE CELL
They information is carried along neurones in an electrical impulse
Three types of neurone!

14. Sensory Neuron
The neurones are responsible for carrying messages from the sensory organs to the CNS

15. Found in the CNS and link the motor and sensory neurones
Relay Neurones
Found in the CNS and link the motor and sensory neurones

16. Motor Neurone
The MOTOR NEURON carries information from the CNS to the EFFECTOR
Effector
(eg muscle)
Axon
Cell Body
Dendrite
Direction of Impulse

17. The Flow of Information
Nerve impulses only travel in ONE DIRECTION
SENSORY NEURONS carry info from the RECEPTORS (sensory organs) to the CNS
RELAY NEURONES link sensory and motor neurons
MOTOR NEURONES carry info from the CNS to the EFFECTOR

18. STIMULI
CNS
EFFECTOR

19. The flow of information: Synapse
Neurons don’t actually touch each other- there is a tiny gap between them, the impulse has to cross this gap, called a synapse.
The impulse crosses the synapse using chemicals called neurotransmitters.
The chemical diffuses across the gap and triggers an impulse in the next neuron.

20. Task: Individual
In your jotters write a summary and draw a diagram showing The journey of the impulse.
Include the words: SENSORY NEURONE, RELAY NEURONE, MOTOR NEURONE, EFFECTOR, SYNAPSE and NEUROTRANSMITTER

21. Control and Communication
Lesson 3- Voluntary and Involuntary Actions

22. Voluntary Actions What does it mean if something is VOLUNTARY?
What are examples of VOLUNTARY actions?

23. Voluntary Actions Requires thinking Slow reaction
Controlled by the brain – the CEREBRUM is involved
For everyday actions

24. Reflex Action
A rapid automatic response to a stimulus (to protect from harm)
Involuntary action- no conscious thought
They happen so fast that there is often no time for them to reach the brain
The impulses pass through the white matter in the SPINAL CORD instead
The brain becomes aware of the action only after it has happened.

25. DEMO

26. The Reflex Arc
The pathway that brings about the reflex action is called the REFLEX ARC- an arrangement of nerve cells which makes sure that we react quickly to hazardous stimuli.

27. The Reflex Arc Stimulus (burn to hand) detected by receptors in skin
Nerve impulses travel along sensory neurone towards CNS
Impulse passed across synapse to relay neuron in spinal cord
Relay neurone passes impulse across second synapse to motor neurone
Impulse travels along motor neurone towards effector (muscle in hand)
Muscle contracts and hand is withdrawn quickly

28. Task: Individual
In your jotters, draw a table comparing a VOLUNTARY action to an INVOLUNTARY action Include: Is thinking required? Speed? What controls it? When do they happen?

29. Voluntary Involuntary
Requires thinking
No thinking required
Slow Reaction
Rapid reaction
Controlled by the brain
Controlled by spinal cord
Everyday reactions
Life saving actions