Functions of Autonomic Nervous System MCQs With Answer
This set of 30 MCQs on the functions of the autonomic nervous system is crafted for B.Pharm students to deepen understanding of ANS physiology and pharmacology. Questions explore sympathetic and parasympathetic functions, autonomic reflexes, neurotransmitters (acetylcholine, norepinephrine), receptor pharmacology (adrenergic α1/α2/β1/β2/β3, cholinergic muscarinic and nicotinic), intracellular signaling, cardiovascular and respiratory control, thermoregulation, and clinically relevant drugs and mechanisms. Emphasis is on mechanisms of action, receptor selectivity, pharmacodynamics, and therapeutic implications to support exam preparation and rational drug use. Answers and explanations help link theory to practice. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which neurotransmitter is primarily released by most sympathetic postganglionic neurons?
- Acetylcholine
- Dopamine
- Norepinephrine
- Serotonin
Correct Answer: Norepinephrine
Q2. Which neurotransmitter acts on muscarinic receptors at target organs in the parasympathetic system?
- Norepinephrine
- Acetylcholine
- Epinephrine
- Glutamate
Correct Answer: Acetylcholine
Q3. What type of receptor mediates fast synaptic transmission at autonomic ganglia and the neuromuscular junction?
- Muscarinic receptor
- Adrenergic α1 receptor
- Nicotinic receptor
- Dopaminergic receptor
Correct Answer: Nicotinic receptor
Q4. Pupil dilation (mydriasis) produced by sympathetic activation is mainly mediated via which receptor?
- β1 receptor
- α2 receptor
- Muscarinic M3 receptor
- α1 receptor
Correct Answer: α1 receptor
Q5. Increased heart rate and contractility during sympathetic stimulation are predominantly due to activation of which receptor?
- β2 receptor
- α1 receptor
- β1 receptor
- Muscarinic M2 receptor
Correct Answer: β1 receptor
Q6. Bronchodilation produced by β-agonists in asthma is mainly mediated by which receptor subtype?
- β1 receptor
- α1 receptor
- β2 receptor
- M3 receptor
Correct Answer: β2 receptor
Q7. Which enzyme rapidly hydrolyzes acetylcholine at cholinergic synapses?
- Monoamine oxidase (MAO)
- Catechol-O-methyltransferase (COMT)
- Acetylcholinesterase (AChE)
- Butyrylcholinesterase
Correct Answer: Acetylcholinesterase (AChE)
Q8. The norepinephrine transporter (NET) is targeted by which class of drugs to increase synaptic NE levels?
- MAO inhibitors
- COMT inhibitors
- NE reuptake inhibitors (e.g., cocaine, SNRIs)
- Acetylcholinesterase inhibitors
Correct Answer: NE reuptake inhibitors (e.g., cocaine, SNRIs)
Q9. Which indirect sympathomimetic causes release of norepinephrine from presynaptic vesicles?
- Phenylephrine
- Amphetamine
- Propranolol
- Atropine
Correct Answer: Amphetamine
Q10. Which muscarinic receptor subtype mediates bronchoconstriction and glandular secretion in airways?
- M1
- M2
- M3
- M4
Correct Answer: M3
Q11. Activation of the carotid baroreceptor reflex by increased blood pressure results primarily in which cardiovascular response?
- Increased sympathetic outflow and tachycardia
- Decreased vagal tone and hypertension
- Increased vagal tone and bradycardia
- Reflex vasoconstriction
Correct Answer: Increased vagal tone and bradycardia
Q12. Which of the following is a non-selective β-adrenergic blocker commonly used in cardiovascular disease?
- Metoprolol
- Propranolol
- Atenolol
- Clonidine
Correct Answer: Propranolol
Q13. Which α1-adrenergic antagonist is used to treat hypertension and urinary obstruction by easing smooth muscle tone?
- Prazosin
- Propranolol
- Phenylephrine
- Isoproterenol
Correct Answer: Prazosin
Q14. Reserpine lowers sympathetic neurotransmission by inhibiting which vesicular transporter?
- NET (norepinephrine transporter)
- VMAT (vesicular monoamine transporter)
- SERT (serotonin transporter)
- DAT (dopamine transporter)
Correct Answer: VMAT (vesicular monoamine transporter)
Q15. Which enzyme is primarily responsible for intraneuronal oxidative deamination of norepinephrine?
- Anhydrase
- Monoamine oxidase (MAO)
- Catechol-O-methyltransferase (COMT)
- Acetylcholinesterase
Correct Answer: Monoamine oxidase (MAO)
Q16. Presynaptic α2-adrenergic receptors reduce norepinephrine release by coupling to which G-protein pathway?
- Gs (stimulatory, ↑cAMP)
- Gq (↑IP3/DAG)
- Gi (inhibitory, ↓cAMP)
- G12/13
Correct Answer: Gi (inhibitory, ↓cAMP)
Q17. Relaxation of the urinary bladder detrusor muscle during urine storage is mainly mediated by which receptor?
- Muscarinic M3
- α1-adrenergic
- β3-adrenergic
- β1-adrenergic
Correct Answer: β3-adrenergic
Q18. Pilocarpine lowers intraocular pressure in glaucoma primarily by which mechanism?
- Decreasing aqueous humor production
- Increasing trabecular outflow via ciliary muscle contraction
- Blocking β receptors in the ciliary body
- Inhibiting carbonic anhydrase
Correct Answer: Increasing trabecular outflow via ciliary muscle contraction
Q19. Which adrenergic receptor subtype predominately stimulates hepatic glycogenolysis?
- α1 receptor
- β2 receptor
- β1 receptor
- Muscarinic M2 receptor
Correct Answer: β2 receptor
Q20. Thermoregulatory (eccrine) sweat glands receive sympathetic innervation that uses which neurotransmitter at the effector?
- Norepinephrine on α receptors
- Acetylcholine on muscarinic receptors
- Epinephrine on β receptors
- ATP on purinergic receptors
Correct Answer: Acetylcholine on muscarinic receptors
Q21. The primary reflex that maintains blood pressure on standing is called:
- Chemoreceptor reflex
- Cough reflex
- Baroreceptor reflex
- Vestibulo-ocular reflex
Correct Answer: Baroreceptor reflex
Q22. Activation of α1-adrenergic receptors typically signals via which second-messenger pathway?
- Gs → ↑cAMP
- Gi → ↓cAMP
- Gq → ↑IP3/DAG → ↑Ca2+
- Tyrosine kinase phosphorylation
Correct Answer: Gq → ↑IP3/DAG → ↑Ca2+
Q23. β-adrenergic receptor activation commonly couples to which G-protein causing increased cAMP?
- Gi
- Gq
- Gs
- G12/13
Correct Answer: Gs
Q24. Administration of atropine produces which primary cardiac effect by blocking muscarinic receptors?
- Bradycardia
- Tachycardia
- Increased AV node conduction block
- Decreased myocardial contractility
Correct Answer: Tachycardia
Q25. Neostigmine improves skeletal muscle strength in myasthenia gravis by which mechanism?
- Blocking nicotinic receptors
- Inhibiting acetylcholinesterase at the NMJ
- Preventing ACh release from nerve terminals
- Activating adrenergic receptors
Correct Answer: Inhibiting acetylcholinesterase at the NMJ
Q26. Which α2-adrenergic antagonist increases sympathetic outflow and can cause anxiety due to enhanced NE release?
- Clonidine
- Yohimbine
- Prazosin
- Propranolol
Correct Answer: Yohimbine
Q27. Which nicotinic receptor subtype is found on autonomic ganglia and the adrenal medulla?
- Nicotinic muscular (Nm)
- Nicotinic neuronal (Nn)
- Muscarinic M2
- α1-adrenergic
Correct Answer: Nicotinic neuronal (Nn)
Q28. The adrenal medulla predominantly releases which hormone into the circulation in response to sympathetic stimulation?
- Norepinephrine only
- Acetylcholine
- Epinephrine
- Dopamine
Correct Answer: Epinephrine
Q29. Which drug is a selective α1-agonist used as a nasal decongestant and to raise blood pressure in hypotension?
- Isoproterenol
- Phenylephrine
- Clonidine
- Dobutamine
Correct Answer: Phenylephrine
Q30. Which muscarinic agonist is commonly used to treat postoperative urinary retention by stimulating bladder contraction?
- Bethanechol
- Atropine
- Neostigmine
- Scopolamine
Correct Answer: Bethanechol
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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