Notes
Autonomic Nervous System — Rapid Revision
Pharmacology · 6 min read · Updated 23 Aug 2026
Cholinergic system
- Neurotransmitter: acetylcholine; receptors — muscarinic (M1-M5, GPCR) and nicotinic (Nm, Nn, ion channels).
- Muscarinic agonists: pilocarpine (glaucoma), bethanechol (urinary retention).
- Antagonists: atropine (organophosphate poisoning), glycopyrrolate, ipratropium.
Adrenergic system
- Alpha-1: vasoconstriction; Alpha-2: presynaptic inhibition; Beta-1: heart; Beta-2: bronchodilation.
- Adrenaline: anaphylaxis, cardiac arrest. Noradrenaline: septic shock.
- Beta blockers: propranolol (non-selective), atenolol/metoprolol (cardioselective).
PSC exam pointers
- Antidote pairs are asked almost every year.
- Know receptor-organ-response tables by heart.