In the autonomic nervous system, fibers from the ganglion to the effector organ are called postganglionic fibers.

Postganglionic fibers in the parasympathetic division, are cholinergic (that is, they use acetylcholine as their neurotransmitters.)

However, postganglionic fibers in the sympathetic division are noradregenic (that is, they use norepinephrine as their neurotransmitters.