And once we generate this action potential, it then travels through the axon of the motor neuron and eventually it ends up on the cell membrane of the skeletal muscle cell. And once it ends up on the cell membrane of that skeletal muscle cell, it generates its own action potential. And this action potential inside the cell ultimately leads to a set of processes that cause the contraction of that muscle. So to see what we mean, let's take a look at the following graph. So, the y axis is the membrane voltage. So as we go up, we basically make it more positive.