Description : Which of the following best describes the mechanism of action of scopolamine ? (a) Irreversible antagonist at nicotinic receptors (b) Irreversible antagonist at muscarinic receptors (c) ... receptors (d) Reversible antagonist at muscarinic receptors (e) Reversible antagonist at nicotinic receptors
Last Answer : Ans: D
Description : Yohimbine is an antagonist of ______ receptors. (a) a1 (b) a2 (c) both (a) and (b) (d) None of the above
Last Answer : Ans: B
Description : Phenylephrine (a) Mimics the transmitter at post-synaptic receptors (b) Displaces transmitter from axonal terminal (c) Inhibits synthesis of transmitter (d) None of the above
Last Answer : Ans: A
Description : Dobutamine differs from dopamine in that (a) It does not activate peripheral dopaminergic receptors (b) It does not activate adrenergic ß receptors (c) It causes pronounced tachycardia (d) It has good blood-brain barrier penetrability
Description : a2–adrenergic receptors are associated with following except (a) Increase in phospholipase C activity (b) Increase in potassium channel conductance (c) Decrease in calcium channel conductance (d) Increase in adenylyl cyclase activity
Description : a1 – receptors are coupled with _______ G protein. (a) Gs (b) Gi (c) Gq (d) Go
Last Answer : Ans: C
Description : 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
Description : Muscarinic cholinergic receptors (a) Are located only on parasympathetically innervated effector cells (b) Mediate responses by opening an instrinsic Na+ ion channel (c) Are present on vascular endothelium which has no cholinergic nerve supply (d) Predominate in the autonomic ganglia
Description : Characteristics of Vitamin D and its metabolites include which one of the following? (a) Act to decrease serum levels of calcium (b) Activation of their Vitamin D receptors increases cellular CAMP ... Vitamin D increase renal excretion of calcium (e) Vitamin D deficiency results in Pager's disease
Description : Oxytremorine is a selective agonist of muscarinic _______ receptors (a) M1 (b) M2 (c) M3 (d) M4
Description : Which of the following is a vasodilator drug used for hypertension that lacks a direct effect on autonomic receptors but may provoke anginal attacks? (a) Amyl nitrite (b) Hydralazine (c) Isosorbide mononitrate (d) Nifedipine (e) Nimodipine
Description : Denervation super-sensitivity includes (a) Proliferation of receptors (b) Loss of mechanism for transmitter removal (c) Increased post-junctional responsiveness (d) All of the above
Description : Norepinephrine binds mainly to (A) α-Adrenergic receptors (B) β-Adrenergic receptrors (C) Muscarinic receptors (D) Nicotinic receptors
Last Answer : Answer : A
Description : The following are true about acetylcholine: a. it has a strong affinity for nicotinic receptors b. is derived from acetyl CoA and choline c. is synthesized by a reaction involving choline acetyltransferase d. all above
Last Answer : all above
Description : The following are true about acetylcholine receptors: a. receptors at all autonomic ganglia are nicotinic b. receptors at the skeletal neuromuscular junction are muscarinic c. ... atropine d. acetylcholine receptors in the neuromuscular junction can be selectively blocked by tubocurarine
Last Answer : acetylcholine receptors in the neuromuscular junction can be selectively blocked by tubocurarine
Description : Anthelmintic action of piperazine is due to: A. Interference with ATP generation in the worm B. Blockade of glucose uptake by the worm C. Hyperpolarization of nematode muscle by GABA agonistic action D. Depolarization of nematode muscle by activating nicotinic receptors
Last Answer : C. Hyperpolarization of nematode muscle by GABA agonistic action
Description : Select the drug which reduces cholesterol synthesis in liver, increases expression of LDL receptors on hepatocytes and has been found to reduce mortality due to coronary artery disease: A. Simvastatin B. Nicotinic acid C. Gemfibrozil D. Colestipol (
Last Answer : A. Simvastatin
Description : Neuromuscular blocking drugs do not produce central actions because: A. They do not cross the blood-brain barrier B. Nicotinic receptors are not present in the brain C. They are sequestrated in the periphery by tight binding to the skeletal muscles D. They do not ionise at the brain pH
Last Answer : A. They do not cross the blood-brain barrier
Description : 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
Last Answer : C. It has additional direct agonistic action on nicotinic receptors at the muscle end plate
Description : Propranolol does not block the following action of adrenaline (a) Bronchodilation (b) Lipolysis (c) Muscle tremor (d) Mydriasis
Description : Propanolol can be used to allay anxiety associated with (a) Chronic neurotic disorer (b) Schizopherenia (c) Short-term stressful situation (d) Endogenous depression
Description : The ß-adrenergic blocker which possesses both ß1 selectivity as well as intrinsic sympathomimetic activity is (a) Alprenolol (b) Atenolol (c) Acebutolol (d) Metoprolol
Description : Which of the following is true of sildenafil (a) It enhances sexul enjoyment in normal men (b) It delays ejaculation (c) It is indicated only for treatment of erectile dysfunction in men (d) It blocks cavernosal a2 adrenoceptors
Description : Prazosin is an effective antihypertensive while nonselective a adrenergic blockers are not because (a) It is the only orally active a blocker (b) It improves plasma lipid profile (c) It does not concurrently enhance noradrenaline release (d) It improves urine flow in males with prostatic hypertrophy
Description : The drug which produces vasoconstriction despite being an a adrenergic blocker is (a) Phenoxybenzamine (b) Ergotamine (c) Dihydroergotoxine (d) Tolazoline
Description : Guanethidine inhibits (a) Synthesis of transmitter (b) Metabolism of transmitter (c) Release of transmitter (d) Displacement of transmitter from axonal terminal
Description : Vasoconstrictors should not be used in (a) Neurogenic shock (b) Haemorrhagic shock (c) Secondary shock (d) Hypotension due to spinal anaesthesia
Description : While undergoing a surgical procedure a patient develops hypotension. Which of the following drugs can be injected intramuscularly to raise his BP (a) Noradrenaline (b) Isoprenaline (c) Mephentermine (d) Isoxsuprine
Description : Continuous exposure of ctecholaminesensitive cells and tissues to adrenergic agonists causes a progressive diminition in their capacity to respond, this phenomenon is called as (a) Refractoriness (b) Desensitization (c) Tachyphylaxis (d) All of the above
Description : Ephedrine is similar to adrenaline in the following feature (a) Potency (b) Inability to penetrate blood-brain barrier (c) Duration of action (d) Producing both a and ß adrenergic effects
Description : Noradrenaline is administered by (a) Subcutaneous injection (b) Intramuscular injection (c) Slow intravenous infusion (d) All of the above routes
Description : Adrenaline raises blood glucose level by the following actions except (a) Inducing hepatic glycogenolysis (b) Inhibiting insulin secretion from pancreatic ß cells (c) Augmenting glucagons secretion from pancreatic a cells (d) Inhibiting peripheral glucose utilization
Description : Low doses of adrenaline dilate the following vascular bed (a) Cutaneous (b) Mucosal (c) Renal (d) Skeletal muscle
Description : A sympathomimetic amine that acts almost exclusively by releasing noradrenaline from the nerve endings is (a) Ephedrine (b) Dopamine (c) Isoprenaline (d) Tyramine
Description : Choose the correct statement from the following about a1 – adrenergic receptor agonists (a) Norepinephrine > isoproterenol > epinephrine (b) Norepinephrine < epinephrine > isoproterenol (c) Epinephrine = norepinephrine >> isoproterenol (d) Epinephrine > isoproterenol > norepinephrine
Description : Tyramine induces release of noradrenaline from adrenergic nerve endings (a) By depolarizing the axonal membrane (b) By mobilizing Ca2+ (c) By a nonexocytotic process (d) Only in the presence of MAO inhibitors
Description : The most efficacious inhibitor of catecholamine synthesis in the body is (a) a - methyl – p - tyrosine (b) a - methyldopa (c) a - methyl - norepinephrine (d) Pyrogallol
Description : Select the correct statement from the following about a1 – adrenergic receptor agonists (a) Isoproterenol > epinephrine = norepinephrine (b) Epinephrine > isoproterenol > norepinephrine (c) Isoproterenol = epinephrine = norepinephrine (d) Epinephrine = norepinephrine > isoproterenol
Description : Atropine is contraindicated in (a) Cyclic AMP (b) Inositol trisphosphate (c) Diacyl glycerols (d) G protein
Description : The most effective antidote for belladonna poisoning is (a) Neostigmine (b) Physostigmine (c) Pilocarpine (d) Methacholine
Description : The most suitable mydratic for a patient of corneal ulcer is (a) Atropine sulfate (b) Homatropine (c) Cyclopentolate (d) Tropicamide
Description : Which of the following mydriatics has the fastest and briefest action ? (a) Atropine (b) Homatropine (c) Tropicamide (d) Cyclopentolate
Description : Glycopyrrolate is the preferred antimuscannic drug for use before and during surgery because (a) It is potent and fast acting (b) It has no central action (c) It has antisecretory and vagolytic actions (d) All of the above
Description : 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
Description : Hyoscine differs from atropine in that it (a) Exerts depressant effects on the CNS at relatively low doses (b) Exerts more potent effects on the heart than on the eye (c) Is longer acting (d) Has weaker antimotion sickness activity
Description : Atropine does not exert relaxant/ antispasmodic effect on the following muscle (a) Intestinal (b) Ureteric (c) Bronchial (d) Layngeal
Description : Which of the following organs is innervated only by parasympathetic nerves ? (a) Iris muscles (b) Ciliary muscle (c) Sweat glands (d) Splenic capsule
Description : Drugs that block the a receptor on effector cells at adrenergic nerve endings (a) Antagonize the effects of isoproterenol on the heart rate (b) Antagonize some of the effects of epinephrine on ... the effects of epinephrine on adenylyl cyclase (d) Cause mydriasis (e) Decreases blood glucose levels
Description : A patient is admitted to the emergency room with orthostatic hypotension and evidence of marked GI bleeding. Which of the following most accurately describes the probable autonomic response to this ... constricted pupils, increased bowel sounds (e) Rapid heart rate, constricted pupils, warm skin