The Nervous System

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The Nervous System

• Biology
• Ms. Bowie

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Nervous System

• By the end of the lesson you should be able to
• Describe how messages travel from the sensory
  receptors around your body, to the brain and then
  back to a muscle.
• Describe the reflex action and the pathway of the
  reflex arc.
• Describe the role of the central nervous system.
• Describe the parts of the brain and what they do.

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Basic nerve cell structure
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3 main types of nerve cells
Sensory neuron Detects a stimulus
Inter neuron Carries the message to from the
brain
Motor neuron Causes a muscle to respond to the
stimulus
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Transmission of signals
Nerve messages take the form a electrical
impulses and travel very fast along the axon of
the nerve cell. When the electricity hits the
end of the nerve cell, chemicals are pushed out
of the cell, travel across the small gap (called
the synapse) and dock on the next nerve
cell. This triggers a new electrical impulse in
the next neuron.
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Normal Response to Stimuli
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Reflex Reaction
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The Brain
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The Brain
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