1. The Nervous System

2. The nervous system is made up of the central
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The nervous system is made up of the central
nervous system (CNS) and the peripheral
nervous system.

3. Nervous system- sense organs

4. The Nervous System
We have 5 sense organs that help us detect our surroundings
Ears- Sound and balance
Nose- Chemicals (smell)
Tongue- Chemicals (taste)
Skin- Touch, heat, pressure
Eyes- Light

5. Stimulus Receptor Coordinator Effector Response
The Nervous System
The NERVOUS SYSTEM consists mainly of the brain, the spinal cord, nerve cells (“neurones”) and receptors. CNS Central Nervous System is made up of the brain and spinal cord.
Types of receptor:
Light receptors in the eyes
Sound receptors in the ears
Chemical receptors on the tongue and in the nose
Touch, pressure and temperature receptors in the skin
Changes of position receptors in the ears (balance)
Stimulus Receptor Coordinator Effector Response

6. Examples of reactions Bright light Sour taste Losing balance
Stimulus
Receptor
(i.e. the thing that detects the stimulus)
Effector
(i.e. the thing that will do the reaction)
Response
(i.e. action taken)
Bright light
Eye
Pupil
Pupil constrict
Sour taste
Taste bud
Salivary Gland
Produce saliva
Losing balance
Ear
Muscles
Movement (stop you falling down)
Sit on a drawing pin
Touch receptors
Movement

7. Structure of a motor neurone. The nerve impulse is
carried along the nerve fibre.

8. Extension

9. A reflex arc

10. The impulse goes from receptor to CNS and then to effector to bring about the response. The relay neurone (purple) inside the spinal cord coordinates the response by connecting the sensory neurone to an appropriate motor neurone (green). The information travels from one neurone to another across a small gap called a synapse.