ANS MCQs

1. TIME: 30 MINS; MARKS: 30; DATE: 03.06.23

2. 1 . Which of the following organs is innervated only by
parasympathetic nerves:
A. Iris muscles
B. Ciliary muscle
C. Sweat glands
D. Splenic capsule

3. 2. The sympathetic and parasympathetic systems exert
functionally opposite influences on the following
parameters except:
A. Heart rate
B. Atrial refractory period
C. Pupil diameter
D. Intestinal motility

4. 3 . Tetrodotoxin blocks nerve impulse/junctional
transmission by:
A. Anticholinergic action
B. Depleting acetylcholine
C. Blocking Na+ channels
D. Blocking Ca2+ channels

5. 4. Muscarinic cholinergic receptors:
A. Are located only on parasympathetically innervated effector cells
B. Mediate responses by opening an intrinsic Na+ ion channel
C. Are present on vascular endothelium which has no cholinergic
nerve supply
D. Predominate in the autonomic ganglia

6. 5. The cardiac muscarinic receptors:
A. Are of the M1 subtype
B. Are of the M2 subtype
C. Are selectively blocked by pirenzepine
D. Function through the PIP2 → IP3/DAG pathway

7. 6. The following inhibitor binds only to the ani-onic site of
the cholinesterase enzyme:
A. Neostigmine
B. Physostigmine
C. Edrophonium
D. Dyflos

8. 7. The organophosphates produce irreversible inhibition
of cholinesterase because:
A. They bind to an allosteric site of the enzyme resulting in
unfavourable conformation of esterati site to bind acetylcholine
B. Regeneration time of the phosphorylated enzyme is longer than
the turnover time of the enzyme molecules
C. Phosphorylation results in rapid degradation of enzyme
molecules
D. They are neither metabolized nor excreted from the body

9. 8. Out of two anticholinesterases, drug ‘X’ is a tertiary amine
while drug ‘Y’ is a quarternary ammonium ompound.
Then:
A. Drug ‘X’ is likely to be more potent than ‘Y’
B. Drug ‘X’ will be more suitable to be used as a miotic
C. Drug ‘Y’ will be completely metabolized in the body
D. Drug ‘Y’ will produce CNS effects

10. 9. Neostigmine is preferred over physostigmine for treating
myasthenia gravis because:
A. It is better absorbed orally
B. It has longer duration of action
C. It has additional direct agonistic action on nicotinic
receptors at the muscle end plate
D. It penetrates blood-brain barrier

11. 10. The mechanism by which neostigmine improves
contraction of myasthenic muscle involves:
A. Repetitive binding of the acetylcholine molecules to the
same receptors at the muscle endplate
B. Diffusion of acetylcholine released from motor nerve
endings to a wider area activating neighbouring receptors
C. Activation of motor end-plate receptors by neostigmine
molecules themselves
D. All of the above

12. 11. Edrophonium is more suitable for differentiating
myasthenic crisis from cholinergic crisis because of its:
A. Shorter duration of action
B. Longer duration of action
C. Direct action on muscle end-plate
D. Selective inhibition of true cholinesterase

13. 12. Which of the following is a relatively cerebroselective
anticholinesterase found to afford symptomatic
improvement in Alzheimer's disease:
A. Donepezil
B. Gemfibrozil
C. Pyridostigmine
D. Pyritinol

14. 13. To be used as a topically applied ocular beta blocker a
drug should have the following properties except:
A. Strong local anaesthetic activity
B. High lipophilicity
C. High ocular capture
D. Low systemic activity

15. 14. The following is an á2 adrenergic agonist used as
eyedrops to lower intraocular pressure:
A. Brinzolamide
B. Bambuterol
C. Brimonidine
D. Latanoprost

16. 15. Which of the following is a prodrug of adrenaline used
topically in glaucoma:
A. Brimonidine
B. Dipivefrine
C. Phenylpropanolamine
D. Dorzolamide

17. 16. Apraclonidine is a clonidine congener which is used:
A. To suppress opioid withdrawal syndrome
B. To suppress menopausal syndrome
C. As Analgesic
D. To reduce intraocular tension

18. 17. Dorzolamide is a:
A. Topically applied ocular carbonic anhydrase inhibitor
B. Second generation sulfonylurea hypoglycaemic
C. Topical sulfonamide antibacterial
D. Luminal amoebicide

19. 18. Choose the correct statement about latanoprost:
A. It is a PGF2á derivative used in glaucoma
B. It is a selective á1 blocker used in benign hypertrophy of
prostate
C. It is a 5-á-reductase inhibitor used to reduce the size of
enlarged prostate gland
D. It is a PGE2 analogue used intravaginally for cervical
priming

20. 19. Select the diuretic that is most effective in acute
congestive glaucoma:
A. Indapamide
B. Amiloride
C. Mannitol
D. Furosemide

21. 20. Neostigmine is beneficial in cobra envenomation
because:
A. It binds to and inactivates cobra toxin
B. It reverses coma due to cobra toxin
C. It counteracts the cardio-depressant action of cobra toxin
D. It antagonizes the paralysing action of cobra toxin

22. 21. A suspected case of poisoning has been brought to the
casualty with weakness, fainting, involuntary passage
of urine and stools, profuse sweating, salivation,
watering from nose and eyes. His pulse is 120/min, low
volume, BP 90/60 mm Hg, respiration shallow, pupil
constricted, muscles flabby with occasional fasciculations.
Which is the most likely type of poisoning:
A. Belladonna
B. Barbiturate
C. Anticholinesterase
D. Dicophane (DDT)

23. 22. Which is the most important drug in the treatment of
organophosphate poisoning:
A. Atropine sulfate
B. Pralidoxime
C. Diazepam
D. Adrenaline

24. 23. Atropine does not antagonise the following feature of
anticholinesterase poisoning:
A. Hypotension
B. Central excitation
C. Muscle paralysis
D. Bronchoconstriction

25. 24. Pralidoxime can reactivate cholinesterase enzyme
that has been inactivated by:
A. Carbamate anticholinesterases
B. Organophosphate anticholinesterases
C. Both carbamate and organophosphate ticholinesterases
D. Reversible anticholinesterases

26. 25. Atropine produces the following actions except:
A. Tachycardia
B. Mydriasis
C. Dryness of mouth
D. Urinary incontinence

27. 26. The organ most sensitive to actions of atropine is:
A. Gastric glands
B. Salivary glands
C. Urinary bladder muscle
D. Heart

28. 27. The quarternary analogues of belladonna alkaloids are
preferred over the natural alkaloids for antisecretory/
antispasmodic indications because:
A. They have additional nicotinic receptor blocking activity
B. They are incompletely absorbed after oral administration
C. They are devoid of CNS and ocular effects
D. Dose to dose they are more potent than atropine

29. 28. Inhaled ipratropium bromide has the following
advantages except:
A. It does not alter respiratory secretions
B. It does not depress airway mucociliary clearance
C. It has faster onset of bronchodilator action than inhaled
salbutamol
D. It only rarely produces systemic side effects

30. 29. Which of the following anticholinergic drugs is primarily
used in preanaesthetic medication and during surgery:
A. Glycopyrrolate
B. Pipenzolate methyl bromide
C. Isopropamide
D. Dicyclomine

31. 30. Children are more susceptible than adults to the
following action of atropine:
A. Tachycardia producing
B. Cycloplegic
C. Gastric antisecretory
D. Central excitant and hyperthermic

32. THANK
YOU