1. Reflexes
L.O: To know what a reflex is and how they work
Can you measure your pupil in the light and dark? Remember don’t touch your eye!

2. Can you move your body without using your brain?
What is a reflex?
Reflex action is a rapid automatic and involuntary response to a stimulus which is not under the control of the brain.
Can anyone think of any reflexes?
Knee-jerk reflex
Achilles reflex
Touching a hot plate
Coughing
yawning
blinking of eyes
Sneezing
movement of diaphragm during breathing

3. How could you prove that your brain isn’t coordinating a response?

4. Nervous system card sort - Sort the cards into a normal nervous system response and a reflex response - Match the example to the sequence

5. Co-ordinator: Relay neurone
Your brain has no part in this pathways ie reflex arc
Co-ordinator: Relay neurone

6. How do reflexes work?
Video

7. Label your diagram and explain in your own words how a reflex works, using the words Stimuli, Receptor, Sensory neuron, Interneuron, spinal cord, motor neuron, muscle, contracts, reflex action

8. Explain the reflex pathway when you touch a hot tripod

9. What are the differences between the motor and sensory neurones?
Takes messages from receptors to the brain or spinal cord
Motor Neurone:
Takes messages from the brain or spinal cord to the muscles and organs

11. Neurones join at synapses
Chemicals are secreted between the gaps
Synapses slow down impulses, but one neurone can synapse several
A relay neurone has synapses with a sensory and motor neurone and also those to the brain

13. How do the following drugs work?
Paracetamol
Aspirin
Dentists procaine injected into gums
Curare given to patients undergoing surgery to stop muscles moving

14. Plenary
Explain what these words mean
Stimulus
Receptor
Sensory neurone
Relay neurone
Motor neurone
Effector
Response
Reflex arc

15. 1. Which is the correct sequence for a nervous response
A – Stimulus, receptor, co-ordinator, response, effector
B – Receptor, effector, stimulus, co-ordinator, response
C – Stimulus, Receptor, co-ordinator, effector, response
D – Stimulus, effector, co-ordinator, receptor, response

16. 2. Which is the receptor in your eyes?
A – Sound receptor
B – Smell receptor
C – Pressure receptor
D – Light Receptor

17. 3. Which is the neurone which takes impulses from your receptor to your spinal cord?
A- Sensory neurone
B – Relay neurone
C – Connector neurone
D - Motor neurone

18. 4. What part of your nervous system is missed in a quick reflex response?
A – Relay neurone
B – Spinal cord
C – Brain
D - Effector

19. 5. Which of these stimulus is the correct one for feeling hot water
A – Taste
B – Light
C – Temperature
D - Touch

20. 6. Which one of these is not an effector?
A – Leg muscle
B – Biceps
C - Salivary glands
D – Ear drum

21. Answers

22. 1. Which is the correct sequence for a nervous response
A – Stimulus, receptor, co-ordinator, response, effector
B – Receptor, effector, stimulus, co-ordinator, response
C – Stimulus, Receptor, co-ordinator, effector, response
D – Stimulus, effector, co-ordinator, co-ordiantor, receptor, response

23. 2. Which is the receptor in your eyes?
A – Sound receptor
B – Smell receptor
C – Pressure receptor
D – Light Receptor

24. 3. Which is the neurone which takes impulses from your receptor to your CNS
A- Sensory neurone
B – Relay neurone
C – Connector neurone
D - Motor neurone

25. 4. What part of your nervous system is missed in a quick reflex response?
A – Relay neurone
B – Spinal cord
C – Brain
D - Effector

26. 5. Which of this stimulus’s is the correct one for feeling hot water
A – Taste
B – Light
C – Temperature
D - Touch

27. 6. Which one of these is not an effector?
A – Leg muscle
B – Biceps
C - Salivary glands
D – Ear drum