And the muscle cell is wrapped around with a special membrane known as our sarcolema. Now, the sarcolema consists of these imaginations, these tunnels that basically go deep into the cell, and these are known as T tubules or transverse tubules. They are shown in the diagram with these white dots. So this is the axon of the motor neuron that is carrying our action potential. And essentially the action potential travels along the axon until it gets to our axon terminal. So this is one axon terminal, a second axon terminal, a third axon terminal.