Pharmacokinetics, Pharmacodynamics, Pharmacology of Autonomic nervous system drugs, Autocoids

71.    Noradrenaline is the neurotransmitter at:

a.    sympathetic preganglionic fibers.

b.    parasympathetic postganglionic fibers.

c.    parasympathetic fibers.

d.    sympathetic postganglionic fibers to the heart.

72.    Which of the following compounds is / are related to the structure of catecholamines?

a.     dopamine.

b.     tyramine.

c.     ephedrine.

d.     isoprenaline.

73.    Which of the following statements concerning infusion of catecholamines is / are true?

a.     noradrenaline increases pulse rate.

b.     isoprenaline increases pulse rate.

c.     isoprenaline increases peripheral resistance.

d.     noradrenaline increases blood pressure. 

74.   The following refer to sympathomimetic drugs:

a.     all sympathomimetic drugs produce their effects by acting on an adrenoceptor.

b.     non-catecholamines do not cross the blood-brain barrier.

c.     ephedrine is orally active.

d.     the effect of amphetamine is prolonged in patients with alkalinized urine.

75.    Which statement(s) is / are true concerning adrenoceptor antagonists?

a.      phenytoin produces a non-competitive blockade.

b.      propranolol has more intrinsic activity than proctalol.

c.      metoprolol is a relatively selective beta-antagonist.

d.      labetalol is an antagonist of alpha and beta adrenoceptors.

76.    Neuromuscular blockade is antagonized by:

a.      neostigmine.

b.      halothane.

c.      ampicillin.

d.      streptomycin.

77.    In the isolated rabbit small intestine preparation,

a.      phentolamine stimulates beta-adrenergic receptors to produce contraction.

b.      inhibition of contraction by isoprenaline are antagonized by propranolol.

c.      phentolamine increases spontaneous contraction.

d.      propranolol has significant action on spontaneous contraction.

78.    Plasma T1/2 of a drug:

a.      is the same as biological T1/2.

b.      is the time required for concentration of drug in plasma to be reduced by 1/2.

c.      is usually lengthened if biologically active metabolites are formed.

d.      determine steady state clearance. 

79.    Acetylcholine is the neurotransmitter at:

a.      sympathetic preganglionic nerve fibers.

b.      sympathetic postganglionic fibres to the heart.

c.      parasympathetic preganglionic fibres.

d.      parasympathetic postganglionic fibres.

80.    D-tubocurarine:

a.      is a quarternary ammonium compound.

b.      causes depolarizing type of neuromuscular blockade.

c.      has a shorter duration of action than succinylcholine.

d.      causes hypotension by blocking autonomic ganglia and stimulating histamine release from tissues.

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