Autonomic Nervous System MCQs


1. The major postjunctional cholinergic receptor is of the muscarinic type at the following site

(a) Postganglionic parasympathetic

(b) Adrenal medulla

(c) Autonomic ganglia

(d) Neuromuscular junction

ANSWER:  [  a  ]


2. The following cotransmitter is most probably involved in mediating nonadrenergic noncholinergic (NANC) relaxation of the gut

(a) Neuropeptide Y

(b) Adenosine

(c) Nitric oxide

(d) Kallidin

ANSWER:  [  c  ]


3. 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

ANSWER:  [  b  ]


4. Which of the following organs is innervated only by parasympathetic nerves

(a) Iris muscles

(b) Ciliary muscle

(c) Sweat glands

(d) Splenic capsule

ANSWER:  [  b  ]


5. Tetrodotoxin blocks nerve impulse/junctional transmission by

(a) Anticholinergic action

(b) Depleting acetylcholine

(c) Blocking Na+ channels

(d) Blocking Ca2+ channels

ANSWER:  [  c  ]


6. The cotransmitter may serve the following function/ functions

(a) Regulate the release of the primary transmitter from the nerve ending

(b) Alter postjunctional action of the primary transmitter

(c) Itself act as an alternative transmitter

(d) All of the above

ANSWER:  [  d  ]


7. Pseudocholinesterase differs from true cholinesterase in

(a) It does not hydrolyse acetylcholine

(b) It hydrolyses acetylcholine at a slower rate

(c) It is more susceptible to inhibition by physostigmine

(d) It is the only form of circulating cholinesterase

ANSWER:  [  b  ]


7. Indicate the location of M2 cholinoreceptor type

(a) Heart

(b) Glands

(c) Smooth muscle

(d) Endothelium

ANSWER: [  a  ]


8. Acetylcholine is not a specific neurotransmitter at

(a) Sympathetic ganglia

(b) Sympathetic postganglionic nerve endings

(c) Parasympathetic ganglia

(d) Parasympathetic postganglionic nerve endings

ANSWER: [  b  ]


9. Parasympathomimetic drugs cause

(a) Bronchodilation

(b) Mydriasis

(c) Bradycardia

(d) Constipation

ANSWER: [  c  ]


10. Isofluorophate increases all of the following effects except

(a) Lacrimation

(b) Bronchodilation

(c) Muscle twitching

(d) Salivation

ANSWER: [  b  ]


11. The cholinergic receptor found in adrenal medulla is

(a) Muscarinic

(b) Muscarinic & Nicotinic

(c) Nicotinic

(d) Alpha

ANSWER: [  c  ]


12. M3 receptor subtype is located

(a) In the myocardium

(b) In sympathetic postganglionic neurons

(c) On effector cell membranes of glandular and smooth muscle cells

(d) On the motor end plates

ANSWER: [  c  ]


13. The site of action of d-tubocurarine is

(a) Spinal internuncial neurone

(b) Motor nerve ending

(c) Muscle end-plate

(d) Sodium channels in the muscle fibre

ANSWER: [  c  ]