The acetylcholine eventually binds onto these receptor proteins that create an action potential. And that action potential ultimately causes the contraction of our biceps muscle. So in this way, it's the brain that generates that electrical signal, but it's the motor neuron of the somatic nervous system that actually causes that movement, that voluntary movement in the first place. Now, one more thing we have to notice about the motor neurons is when they actually leave, when they actually exit the spinal cord, they always exit from the front side, from the ventral side of our spinal cord. So if this is the back and this is the front, notice they always leave from the front side of our spinal cord. Now, one more thing we have to notice is we have a single axon leaving this spinal spinal cord, and the axon eventually ends up exactly at our effective target.