Normal resting potential across membrane is -70mV
Sodium ions rush into the axon causing a region of positive charge
Sodium potassium pump uses ATP to pump K+ ions into neurone and Na+ ions out
When stimulated above the threshold voltage gated sodium channels open
Some potassium ions leak out of the neurone
Potassium channels open and K+ ions leave the axon
The imbalance of ions between inside and outside of neurone causes a resting potential.
This continues along the length of the axon as the impulse is propagated.
The out-flow of potassium repolarises the membrane
The sodium potassium pump restores the resting potential
At the end of the neurone when an impulse arrives, vesicles release a neurotransmitter