Dive into a comprehensive 1-hour 19-minute lecture on receptors, agonists, and their types. Explore the differences between agonists and antagonists, understand various agonist types including full, partial, orthosteric, and allosteric. Learn about affinity, efficacy, and intrinsic activity of ligands. Discover the rationale behind using partial agonists as drugs and examine examples of full and partial agonists in opioid receptors. Investigate positive allosteric modulators, inverse agonists, and the mechanisms of benzodiazepines and barbiturates. Conclude with an overview of direct and indirect agonists, providing a thorough understanding of receptor pharmacology.