SME
Grade 9 Science · Problem type
A nerve impulse
Use this for “What makes the inside of a neuron positive during an impulse?”
Put in order
Put the steps of an action potential in order, from rest.
1
?
2
?
3
?
4
?
5
?
6
?
Assumptions
•
At rest the inside of a neuron is about −70 mV, more negative than the outside.
•
The Na⁺/K⁺ pump keeps more Na⁺ outside and more K⁺ inside, ready for the next impulse.
•
Each patch of axon triggers the next, so the impulse travels along it one way.
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The nervous system and the senses
Main lesson
How fast a nerve impulse travels
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Membrane potential through an impulse
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Which part of the nervous system?
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Which receptor detects it?
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