Description : Guanethidine inhibits (a) Synthesis of transmitter (b) Metabolism of transmitter (c) Release of transmitter (d) Displacement of transmitter from axonal terminal
Last Answer : Ans: C
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
Last Answer : Ans: D
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 synaptic pre-ganglionic neurons have their cell bodies in the lateral horn of the grey matter of the (a) Thoracic segment only (b) Lumbar segment only (c) Both (a) and (b) (d) None of the above
Description : Which of the following drugs is the drug of choice in anaphylaxis associated with bronchospasm and hypotension ? (a) Cortisone (b) Epinephrine (c) Isoproterenol (d) Norepinephrine (e) Phenylephrine
Last Answer : Ans: B
Description : When pupillary dilation-but not cycloplegia-is desired, a good choice is (a) Homatropine (b) Isoproterenol (c) Phenylephrine (d) Pilocarpine (e) Tropicamide
Description : A 7-years-old boy has a significant bedwetting problem. A long-acting indirect sympathomimetic agent sometimes used by the oral route for this and other indications is (a) Dobutamine (b) Ephedrine (c) Epinephrine (d) Isoproterenol (e) Phenylephrine
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
Last Answer : Ans: A
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
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 : Yohimbine is an antagonist of ______ receptors. (a) a1 (b) a2 (c) both (a) and (b) (d) None of the above
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 : Following is an antagonist of ganglion type nicotinic receptors (a) Tubercurarine (b) a-bungarotoxin (c) Trimethaphan (d) All of the above
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 : 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
Description : Action of norepinephrine and epinephrine are terminated by (a) Reuptake into nerve terminal (b) Dilution by diffusion and uptake at extraneuronal site (c) Metabolic transformation (d) All of the above
Description : GABA(gama amino butyric acid) is (A) Post-synaptic excitatory transmitter (B) Post-synaptic inhibitor transmitter (C) activator of glia-cell function (D) inhibitor of glia-cell function
Last Answer : Answer : B
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 : Typical results of beta-receptor activation include which one of the following? (a) Hypoglycemia (b) Lipolysis (c) Glycogen synthesis (d) Decreased skeletal muscle tremor (e) Decreased rennin secretion
Description : Following enzyme is involved in the synthesis of actylcholine (a) Choline acetyl transferase (b) Acetyl cholinesterase (c) Both (a) and (b) (d) None of the above
Description : The biochemical mechanism of action of digitalis is associated with (a) A decrease in calcium uptake by the sarcoplasmic reticulum (b) An increase in ATP synthesis (c) A modification of the actin molecule (d) An increase in systolic intracellular calcium levels (e) A block of sodium/calcium exchange
Description : Choose the correct statement about ticlopidine: A. It blocks GPIIb/IIIa receptors on platelet membrane B. It prevents ADP mediated platelet adenylylcyclase inhibition C. It inhibits thromboxane A2 synthesis in platelets D. It does not prolong bleeding time
Last Answer : B. It prevents ADP mediated platelet adenylylcyclase inhibition
Description : The following are true: a. heroin causes miosis by increasing the release of acetylcholine. b. botulinum toxin causes mydriasis by inhibiting the release of acetylcholine c. ... mydriasis by stimulating the alpha receptors d. amphetamine causes mydriasis by inhibiting noradrenaline reuptake
Last Answer : phenylephrine causes mydriasis by stimulating the alpha receptors
Description : Dopaminergic D1 and D2 as well as adrenergic α and β1, but not β2 receptors are activated by: A. Dopamine B. Dobutamine C. Methoxamine D. Phenylephrine
Last Answer : A. Dopamine
Description : The following sympathomimetic amine has agonistic action on α1 + α2 + β1 + β3 adrenoceptors, but not on β2 receptors: A. Adrenaline B. Noradrenaline C. Isoprenaline D. Phenylephrine
Last Answer : B. Noradrenaline
Description : Dopaminergic D1 and D2 as well as adrenergic α and β 1, but not β 2 receptors are activated by: A. Dopamine B. Dobutamine C. Methoxamine D. Phenylephrine
Description : The following sympathomimetic amine has agonistic action on α 1 + α 2 + β 1 + β 3 adrenoceptors, but not on β 2 receptors: A. Adrenaline B. Noradrenaline C. Isoprenaline D. Phenylephrine
Description : The synaptic knobs represent the terminal endings of (a) the neuron (b) the dendron (c) the axon (d) the telodendria
Last Answer : Ans:(d)
Description : When the electric impulse travels along the axon and reaches the other end called the synaptic terminal, this impulse triggers the release of – (1) Vesicles (2) Cleft (3) Mitochondria (4) All of the above
Last Answer : (1) Vesicles Explanation: The electrical impulses stimulate the release of vesicles. These store various neurotransmitters that are released at the synapse. Vesicles are essential for propagating nerve impulses between neurons and are constantly recreated by the cell.
Description : The figure shows an axon terminal and synapse. Select the option giving correct identification of labels A-D. A C D B (a) A-Action potential, C-Neurotransmitter (b) B-Neurotransmitter, D- Receptor capsules (c) C-Receptor, D-Synaptic vesicles (d) A-Axon terminal, B- Serotonin complex
Last Answer : c) C-Receptor, D-Synaptic vesicles
Description : A diagram showing axon terminal and synapse is given. Identify correctly at least two of A - D. (a) A - Neurotransmitter, B - Synaptic cleft (b) C - Neurotransmitter, D - Ca++ (c) A - Receptor, C - Synaptic vesicles (d) B - Synaptic connection, D - K+
Last Answer : (c) A - Receptor, C - Synaptic vesicles
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 : 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 : 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