And that means each one of these motor neurons, their dendrites and the cell bodies originate begin at the central nervous system. Now the axon of the motor neuron basically extends and the axon terminal of each one of these motor neurons basically ends up at the muscle cells that they control. So motor neuron number one, as well as all the muscle cells that motor neuron number one controls is known as motor unit number one. The same thing goes for number two. We have motor unit number two that consists of motor neuron number one and the muscle cells that it controls. And the same thing is true for motor neuron number three.