ANS questions Flashcards
A 3-year-old child has swallowed the contents of 2 bottles of a nasal decongestant whose primary ingredient is a potent, selective α-adrenoceptor agonist drug. Which of the following is a sign of α-receptor activation that may occur in this patient?
A. Bronchodilation B. cardiac acceleration [tachycardia] C. pupillary dilation [mydriasis] D. Renin release from kidneys E. vasodilation splanchnic vessels
Answer: C pupillary dilation [mydriasis]
Explanation: smooth muscle ciliary cells in eyes have alpha receptors, all other responses mediated by B adrenoceptors
An anesthetized dog is prepared for recording blood pressure and heart rate in a study of a new blocking drug. Results show that the new drug prevents the tachycardia evoked by isoproterenol? Which of the following standard agents does the new drug most resemble?
A. Atropine B. Hexamethonium C. phentolamine [alpha blocker[ D. physostigmine E. propanolol
Answer: E. propanolol
ioproterenol activates HR via combo of B1 and B2 reflex response. propanolol is a B blocker
Nicotinic receptor sites do not include which one of the following sites?
A. bronchial smooth muscle B. adrenal medulllary cells C. parasympathetic ganglia D. Skeletal muscle end plates E. sympathetic ganglia
A. bronchial smooth muscle
explanation: all of the others are ganglia + the adrenal medulla is a modified form of sympathetic ganglia
Which one of the following can be blocked by atropine?
A. decreased BP caused by hexamothonium B. increased BP caused by nicotine C. increased skeletal muscle strength caused by neostigmine D. tachycardia caused by exercise E. tachycardia caused by infusion ACH
Answer: E. tachycardia caused by infusion acetyl choline
Atropine blocks muscarinic and thus inhibits PNS,
acetylcholine infusion causes vasodilation and thus by reflex response get increased HR
A 30-year-old man has been treated with several autonomic drugs for 4 weeks. He is now admitted to the emergency department showing signs of drug toxicity. Which of the following signs would distinguish between an overdose of a ganglion blocker versus a muscarinic blocker?
A. blurred vision B. dry mouth, constipation C. mydriasis D. postural hypotension E. tachycardia
Answer: D. postural hypotension
both ganglion blockers and muscarinic blocks cause mydriasis, increased HR, blur vision, cause constipation
postural hypotensions ia sign of sympathetic blockade, would not happen in muscarinic blocker
Actions and clinical uses of muscarinic cholinoceptor agonists include which one of the following?
A. bronchodilation [asthma]
B. improved
