The parasympathetic nervous system secretes the neurotransmitter ____ from its postganglionic nerve fibers, and this neurotransmitter binds with ___ receptors on target tissues/effector organs.
Norepinephrine, alpha- or beta- adrenergic
Epinephrine, alpha- or beta- adrenergic
Acetylcholine, nicotinic cholinergic
Acetylcholine, muscarinic cholinergic
two of these