What's a word i can use to describe someone who puts them selves or their needs before someone else but not in a bad or selfish way?

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link: