1. The nervous system

2. Recap: The nervous system
Main Function:
This communication system controls and coordinates functions throughout the body and responds to internal and external stimuli.
Our nervous system allows us to feel pain.

3. Recap: Nervous system It consists of 2 parts:
The central nervous system consists of the brain, spinal cord (CNS),
The peripheral nervous system contain the other nerves and receptors of our body.

4. Notes: Sympathetic nervous system
Speeds up functions of the body
Prepares body for emergencies
Makes body alert and ready to act
Diverts blood away from digestive tract
Stops peristalsis
Opens bronchioles – more oxygen
Increases heart rate
Dilates pupil – more light
Increase blood flow to heart

5. Notes: Para-sympathetic nervous system
Slows everything down
In control when you are resting
Increases blood flow to digestive tract
Stimulates salivary galnds
Reduces bronciole diameter- less oxygen
Controls heart beat
Reduces diameter of pupil

6. Notes: How is information transmitted?
Information passes from receptors along nerve cells called neurones.
Nerve cells are long and thin to carry messages called impulses.
Cell body
Dendrites
Myelin sheath
nucleus
Axon

8. Task: Draw a neuron
Cell body: contains nucleus & most of the cytoplasm
Dendrites: projections that bring impulses into the neuron to the cell body.
Axon: long projection that carries impulses away from cell body 1 3 2

9. Notes: There are 3 types of neurone:
Sensory neurone – carry impulse from receptor to CNS
Relay – connects sensory to motor
Motor – connects CNS to effector which makes a response. (muscle, gland)

10. Reflexes protect the body before the brain knows what is going on.
Reflex Arc
A reflex is an involuntary response that is processed in the spinal cord not the brain.
Reflexes protect the body before the brain knows what is going on.

11. Reflex response – Draw flow of signal
Stimulus >> receptor>> sensory >> co –ordinator (spinal cord) >> motor >> Effector >Response

12. Neurotransmitters
Neurotransmitters are chemicals that transmit signals from a neuron to a target cell across a synapse (gap)

13. Define – Neuro-transmitter
Because neurons never touch, chemical signalers called neurotransmitters must travel through the space called synapse between two neurons.
Neurotransmitters
(pink
spheres)
The message is transferred when RECEPTORS receive neurotrans-mitters.
Synapse (gap)

14. Neurotransmitters

15. Ruler drop test Aim Variables Hypothesis Materials Procedure Safety
Data table

16. Ruler drop test Graph – comparison of response in your group
Analyse numbers etc
Conclusion of findings
Evaluation

17. Analysis questions to consider
1. What happened to ………….. reaction time as he had more tries?
2. What happened to ……………. reaction time as she had more tries?
3. Who improved the most from the first to the fifth try?
4. Who had the fastest reaction time?
5. What do you think might happen if ……….. has more tries?
6. What have you found out about reaction time so far?
7. What else would you like to find out about reaction time?

18. What might we be able to find out from our investigation?
Who has the fastest reaction time in the class?
Do boys have better or worse reaction times than girls?
Do sporty people have the fastest reaction times?
Do people who play video games have the fastest reaction times?
Does the oldest person in the class have the fastest reaction time?
Do children have faster reaction times than grown ups?
If you try the reaction test every day for a week will your reaction time improve?