Final answer:
The postganglionic fibers of the sympathetic division typically release norepinephrine as their neurotransmitter, which binds to adrenergic receptors on target cells.
Step-by-step explanation:
The postganglionic fibers of the sympathetic division predominantly release norepinephrine as their neurotransmitter. This chemical binds to adrenergic receptors present on target cells, triggering a sympathetic response that prepares the body for 'fight or flight' actions. The release of norepinephrine by these fibers contrasts with postganglionic parasympathetic fibers which liberate acetylcholine (ACh), binding to muscarinic receptors on their target cells. An exception exists in that postganglionic sympathetic fibers that project to sweat glands and certain blood vessels release ACh instead of norepinephrine.