Acetylcholine [Acetylene torch with coal] is stored in vesicles in the presynaptic bouton. After release, it is cleared from the synapse by acetylcholinesterase and reabsorbed by the presynaptic neuron via Na-coupled transport
Black Widow spider venom causes the vesicles to spill [spider pierces vesicles]
Curare derivatives (e.g. tubocurarine) [curare tube arrow] penetrate into muscle and block nicotinic receptors
Muscarinic receptors are in CNS, heart, and stomach (stomach has a sub-category "M2" receptors) [Musk ox with colored organs]
Muscarinic receptors act via DAG, IP3/Ca++ second messenger system [Dog leading the ox, also used by alpha-1 (A1 sauce) adrenergic receptors]
pirenzepine blocks stomach-specific M2 receptors [piranha and pine bite acetylcholine]
Pilocarpine [Peeling carp pine] stimulates muscarinic receptors [pretends to be a musk-ox by wearing horns] and is useful for both narrow and wide angle glaucoma [eye with angles and small pupil]. Side effects include sweating.