Biology 1 - Nervous System

The Nervous System allows the body to respond to change !

The nervous system consists of...

- Brain

- Spinal Cord

- Spinal Nerves

- Receptors

It allows organismms to react to their surroundings and to co-ordinate their behaviour.

Information from receptors passes along neurones (nerve cells) to the brain which co-ordinates the response.

The Nervous System goes from the....

• Receptor, 
• Sensory Neurones,
• Relay Neurones,
• Spinal Cord,
• Brain,
• Motor Neurones,
• Effector.

There are 3 different types of neurones:

• Motor Neurone

Where impulse travels away from cell body

• Sensory Neurone

Where impulse travels towards the cell body

• Relay Neurone

Where impulse travels away and towards the cell body

Neurones are streched to make connections between parts of the body!

Neurones do not touch each other, there is a very small gap between them called a synapse.

When an electrical impulse reaches a synapse via 'Neurone A' a chemical transmitter is released which activates receptors on 'Neurone B' and causes a electrical impulse to be generated in 'Neurone B' .

The chemical transmitter is then destroyed.

Different receptors detect different stimuli...

- Eyes detect  ...  Light

- Ears detect   ... Sound and Position/Balance

- Nose detects ... Smell

- Mouth detects ... Taste

- Skin detects ... Touch, Pressure, Temperature and Pain.

Sometimes concious actions are too slow to prevent the body from harm...

 Therefore, reflex actions take place, reactions that bypass the brain.

Reflex Actions are Automatic and Quick!

I hope now you feel more confident about the...

NERVOUS SYSTEM !!