Introduction: The autonomic nervous system (ANS) controls involuntary functions—cardiovascular, respiratory, gastrointestinal, ocular and genitourinary—through coordinated sympathetic and parasympathetic pathways. B.Pharm students must master key concepts: neurotransmitters (acetylcholine, norepinephrine, epinephrine), receptor families (nicotinic, muscarinic, alpha, beta subtypes), signal transduction (Gs, Gi, Gq), synthesis and metabolism (tyrosine hydroxylase, COMT, MAO), vesicular transporters (VMAT), and clinically important drugs (agonists, antagonists, cholinesterase inhibitors). Understanding pharmacology, sites of action, therapeutic uses and adverse effects is essential for rational drug therapy. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which neurotransmitter is released by all preganglionic autonomic fibers?
- Acetylcholine
- Norepinephrine
- Dopamine
- Serotonin
Correct Answer: Acetylcholine
Q2. Which nicotinic receptor subtype predominates at autonomic ganglia?
- Nicotinic Nm
- Nicotinic Nn (neuronal)
- Muscarinic M2
- Beta1
Correct Answer: Nicotinic Nn (neuronal)
Q3. Which neurotransmitter is released by parasympathetic postganglionic neurons?
- Norepinephrine
- Acetylcholine
- Epinephrine
- Glutamate
Correct Answer: Acetylcholine
Q4. Dilation of the pupil (mydriasis) primarily involves activation of which receptor?
- Muscarinic M3
- Alpha1 adrenoceptor
- Beta2 adrenoceptor
- Muscarinic M2
Correct Answer: Alpha1 adrenoceptor
Q5. Which adrenergic receptor subtype is mainly coupled to Gs and increases cardiac contractility and heart rate?
- Alpha2
- Beta1
- Muscarinic M3
- Alpha1
Correct Answer: Beta1
Q6. Which enzyme catalyzes the rate-limiting step in catecholamine synthesis (tyrosine → L-DOPA)?
- DOPA decarboxylase
- Tyrosine hydroxylase
- Dopamine β-hydroxylase
- Phenylethanolamine N-methyltransferase
Correct Answer: Tyrosine hydroxylase
Q7. The adrenal medulla secretes predominantly which hormone into the bloodstream?
- Acetylcholine
- Norepinephrine
- Epinephrine
- Dopamine
Correct Answer: Epinephrine
Q8. VMAT (vesicular monoamine transporter) is responsible for:
- Reuptake of norepinephrine into the synaptic cleft
- Transport of monoamines into synaptic vesicles
- Metabolism of catecholamines by MAO
- Degradation of acetylcholine
Correct Answer: Transport of monoamines into synaptic vesicles
Q9. Which cholinesterase inhibitor is commonly used orally for myasthenia gravis?
- Neostigmine
- Pyridostigmine
- Physostigmine
- Donepezil
Correct Answer: Pyridostigmine
Q10. Atropine produces its effects by acting as a:
- Muscarinic receptor agonist
- Nicotinic receptor antagonist
- Muscarinic receptor antagonist
- Beta adrenergic blocker
Correct Answer: Muscarinic receptor antagonist
Q11. Which beta-blocker is relatively selective for β1 receptors at therapeutic doses?
- Propranolol
- Metoprolol
- Prazosin
- Phenylephrine
Correct Answer: Metoprolol
Q12. Clonidine lowers blood pressure primarily through stimulation of which receptor in the CNS?
- Central alpha2 adrenoceptors
- Peripheral alpha1 adrenoceptors
- Beta2 adrenoceptors
- Muscarinic M2 receptors
Correct Answer: Central alpha2 adrenoceptors
Q13. Acute sympathetic stimulation increases heart rate mainly via which receptor?
- Muscarinic M2
- Alpha1
- Beta1
- Beta3
Correct Answer: Beta1
Q14. Which of the following is an example of an irreversible acetylcholinesterase inhibitor (organophosphate)?
- Neostigmine
- Malathion
- Donepezil
- Edrophonium
Correct Answer: Malathion
Q15. Bronchoconstriction in the airways is mainly mediated by activation of which receptor?
- Beta2 adrenoceptor
- Alpha1 adrenoceptor
- Muscarinic M3 receptor
- Muscarinic M1 receptor
Correct Answer: Muscarinic M3 receptor
Q16. Activation of arterial baroreceptors (stretch receptors) produces which autonomic response?
- Increased sympathetic outflow and tachycardia
- Decreased parasympathetic outflow and hypertension
- Increased parasympathetic outflow and decreased sympathetic outflow
- Increased renin release only
Correct Answer: Increased parasympathetic outflow and decreased sympathetic outflow
Q17. Norepinephrine is primarily cleared from the synaptic cleft by which mechanism?
- Catechol-O-methyltransferase (COMT) within the synaptic cleft
- Monoamine oxidase (MAO) in postsynaptic cell
- Uptake-1 via norepinephrine transporter (NET)
- Passive diffusion away from the synapse
Correct Answer: Uptake-1 via norepinephrine transporter (NET)
Q18. Which drug is an alpha1-selective antagonist commonly used to treat hypertension and benign prostatic hyperplasia?
- Propranolol
- Prazosin
- Clonidine
- Isoproterenol
Correct Answer: Prazosin
Q19. Presynaptic inhibition of norepinephrine release is mediated mainly by which receptor subtype?
- Alpha1 adrenoceptor
- Alpha2 adrenoceptor
- Beta1 adrenoceptor
- Muscarinic M3 receptor
Correct Answer: Alpha2 adrenoceptor
Q20. Extraneuronal metabolism of circulating catecholamines is chiefly carried out by which enzyme?
- Monoamine oxidase (MAO)
- Catechol-O-methyltransferase (COMT)
- Acetylcholinesterase
- DOPA decarboxylase
Correct Answer: Catechol-O-methyltransferase (COMT)
Q21. Succinylcholine is classified pharmacologically as a:
- Nondepolarizing neuromuscular blocker
- Depolarizing neuromuscular blocker
- Muscarinic agonist
- Acetylcholinesterase inhibitor
Correct Answer: Depolarizing neuromuscular blocker
Q22. Which cholinesterase inhibitor is widely used to treat symptoms of Alzheimer’s disease?
- Neostigmine
- Donepezil
- Edrophonium
- Malathion
Correct Answer: Donepezil
Q23. Parasympathetic stimulation of the eye and airways causes which of the following effects?
- Mydriasis, bronchodilation, decreased salivation
- Miosis, bronchoconstriction, increased glandular secretion
- Mydriasis, bronchoconstriction, decreased heart rate
- Miosis, bronchodilation, increased heart rate
Correct Answer: Miosis, bronchoconstriction, increased glandular secretion
Q24. Which β2-selective agonist is commonly used as a short-acting bronchodilator in asthma?
- Salbutamol (albuterol)
- Propranolol
- Prazosin
- Phenylephrine
Correct Answer: Salbutamol (albuterol)
Q25. Which co-transmitter released from sympathetic nerves contributes to prolonged vasoconstriction?
- Substance P
- Neuropeptide Y (NPY)
- Histamine
- Glutamate
Correct Answer: Neuropeptide Y (NPY)
Q26. Relaxation of the urinary bladder detrusor during storage is primarily mediated by which receptor subtype?
- Muscarinic M3
- Alpha1 adrenoceptor
- Beta3 adrenoceptor
- Beta1 adrenoceptor
Correct Answer: Beta3 adrenoceptor
Q27. The cell bodies of sympathetic preganglionic neurons are located in which region of the spinal cord?
- Dorsal horn at C3–C5
- Lateral horn at T1–L2
- Lateral horn at C1–C4
Correct Answer: Lateral horn at T1–L2
Q28. Which drug depletes catecholamines by inhibiting VMAT and is associated with depression as an adverse effect?
- Reserpine
- Amphetamine
- Clonidine
- Phenylephrine
Correct Answer: Reserpine
Q29. Which muscarinic receptor subtype primarily mediates smooth muscle contraction in the gastrointestinal tract?
- Muscarinic M1
- Muscarinic M3
- Muscarinic M4
- Muscarinic M5
Correct Answer: Muscarinic M3
Q30. A known adverse effect of nonselective beta-blockers in patients with asthma is:
- Reflex tachycardia
- Bronchoconstriction and worsening bronchospasm
- Excessive saliva production
- Mydriasis
Correct Answer: Bronchoconstriction and worsening bronchospasm
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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