The first neuron is known as our pre ganglionic neuron and the second neuron is known as the post ganglionic neuron. Now, all pre ganglionic neurons in a sympathetic nervous system begin in the spinal cord of our body. So the cell, body and the dendrites of the pre ganglionic neuron are found in our spinal cord when they actually exit. When the axon exits our spinal cord, it always exits from the front side, known as our ventral side. And the axon of the pre ganglionic neuron is relatively short compared to our axon of the post ganglionic neuron. Now, at the first synapse between our pre ganglionic and the post ganglionic cell of the sympathetic nervous system we use acetylcholine as our neurotransmitter to pass that signal from our pre to our post ganglionic cell.