The city at night represents the inside of the neuron when it is at rest. It is filled with a negative people and has some movement in an out of it(facilitated diffusion) .
Depolarization: We can see that in the morning people who live outside of the city(positive charged sodium) come into the city because of work(stimulus). With this change in polarity the negative charge is transferred to the outside of the city(membrane).
Repolarization: At the end of the day(threshold) offices (sodium ion channels) close and it becomes night time where the clubs (positive potassium channels) open and bring the negative charge back into the city by getting rid of the positive potassium ions.
Refractory Phase: This is the part where returns to the starting state of the cell. This is very similar to the weekend where you go through the activities that you don't normally do, but then at the end of the weekend you return to the normal lifestyle.During the refractory phase this particular area of the nerve cell membrane cannot be depolarized. Therefore, the neuron cannot reach action potential during this “rest period.”