The Nervous System
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What are nerves?
The nervous system helps us to react to our
surroundings and co-ordinate our behaviour.
A nerve is a bundle of many nerve fibres
enclosed within a protective sheath.
Nerve fibres are the long axons of
neurones together with any
associated tissues.
nerve
nerve fibre
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The two parts of the nervous system
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The structure of a neurone
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Sensory, relay and motor neurones
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Stimulus to response
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What is a synapse?
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The action of stimulants
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Key terms
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How fast are electrical signals?
Nerve impulses travel at up to 100 metres per second.
How long would it take you to run this distance?
How long would it take to drive it?
You can carry out a simple
experiment on the speed of the
transmission of a nerve
impulse by standing in a circle
and holding hands.
Close your eyes. Time how
long a squeeze takes to be
passed around the circle, from
the start to the finish.
How accurate is this experiment?
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A reflex arc
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The sequence of a reflex arc
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Glossary
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Anagrams
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Multiple-choice quiz
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