So this is explained in the following diagram. So, as our action potential moves over this way, the region right and back of that action potential is experiencing a refractory period, absolute refractory. And that means our sodium channels on the cell membrane here and here are inactivated. And no matter how high our stimulus is, no action potential can be generated in this section. And so our action potential does not actually move in a backward direction towards Arasoma and only moves towards our axon terminal. And this is shown in the following diagram.