system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If the human body is run on electrical impulses, what is the mechanism by which these impulses are generated and maintained?
gpt
It's the repolarization and depolarization of your axons in the nervous system.

The ions sodium (Na) and potassium (K) create an electrochemical gradient between the inside and outside of your axons. There is more positive ions (note they are both positive ions) in the outside of the axon and less in the axon, creating the electron chemical gradient. This different in electrochemical gradient is -60mV, which its the resting membrane potential. 

When axons fire, they send a cascade of opening and closing of ion channels, the first step is depolarization, Na channels open up and they rush into the axon making the inside more positive (up to +40mV)

Then the K channels up open when the electrochemical gradient reaches +40 mV and K flows out of the axon making the axon more negative. This is repolarization. 

Then you have hyper polarization, which is essentially the Na-K pump returning everything back to -60mV

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The actual ELI5: chemicals create an **electro**chemical gradient. That is the electrical impulse that we can detect. Mechanism: chemicals move back and forth across the axon membrane which conduct the impulse forward. Sodium ion channels, potassium ion channels and Sodium-potassium pump maintain this mechanism.