This document discusses the pharmacology of nicotinic and muscarinic agonists and antagonists. It describes how nicotine preferentially stimulates ganglionic nicotinic receptors and the complex effects this has on the cardiovascular, gastrointestinal, and urinary systems. It also discusses ganglionic blockers that reduce transmission in both the sympathetic and parasympathetic ganglia. Finally, it covers nicotinic antagonists that act as skeletal muscle relaxants, including non-depolarizing drugs like tubocurarine and depolarizing drugs like succinylcholine.