So now let's talk a little bit about the interaction between the pre- and postganglionic neurons.
After the axons of the sympathetic preganglionic neurons enter the sympathetic trunk ganglia,
they may connect with the postganglionic neuron in four different ways.
The first way, an axon may synapse with the postganglionic neuron in the first ganglion it reaches.
So for example, it may leave from T1 and then connect or synapse at the T1 ganglia.
A second way is when an axon may ascend or descend to a higher or lower ganglion
before synapsing with its postganglionic neuron.
So for example, it may exit from T1 but not synapse until it gets to C1, above it, or to T8 below it.
A third way that they may interact is when an axon continues without synapsing
through the sympathetic trunk ganglion and then ends at a prevertebral ganglion,
and this is where the synapses occurs.
The nerves associated with this type of interaction are referred to as splanchnic nerves.
Finally, an axon may also pass without synapsing through the sympathetic trunk ganglion,
the prevertebral ganglion, and then extend all the way to the adrenal medulla of the kidneys.
The adrenal medulla is part of the renal gland and sits right on top of the kidneys.
Inside of the adrenal medulla, we have a type of cell called chromaffin cells.
The chromaffin cells of the adrenal medulla are functionally similar to that of the postsynaptic neuron.
These cells secrete or release norepinephrine.