ATI RN
Drug and Dosage for ET Tube Cardiovascular Pharmacological Agents Questions
Question 1 of 5
The excessive stimulation of muscarinic receptors by pilocarpine and choline esters is blocked competitively by:
Correct Answer: B
Rationale: Rationale: 1. Atropine is a muscarinic receptor antagonist. 2. It competes with pilocarpine and choline esters for the muscarinic receptors. 3. By binding to the receptors, atropine blocks the excessive stimulation. Summary: - A: Edrophonium is an acetylcholinesterase inhibitor, not a muscarinic receptor antagonist. - C: Pralidoxime is used to treat organophosphate poisoning, not muscarinic receptor overstimulation. - D: Echothiophate is a long-acting acetylcholinesterase inhibitor, not a muscarinic receptor antagonist.
Question 2 of 5
Characteristics of methoxamine include all of the following EXCEPT:
Correct Answer: B
Rationale: The correct answer is B because methoxamine is a direct-acting alpha1-receptor agonist that increases blood pressure by causing vasoconstriction and increasing total peripheral resistance. It does not increase heart rate, contractility, or cardiac output; instead, it can cause reflex bradycardia due to its hypertensive effect. Therefore, the statement that it increases heart rate, contractility, and cardiac output is incorrect. The other choices (A, C, and D) are all characteristics of methoxamine, making them incorrect options for this question.
Question 3 of 5
Beta-receptor antagonists have all of the following cardiovascular effects EXCEPT:
Correct Answer: B
Rationale: The correct answer is B. Beta-receptor antagonists, also known as beta-blockers, do not cause a fall in peripheral resistance as an acute effect. Here's why: A, negative inotropic and chronotropic effects, occur because beta-blockers decrease heart rate and contractility. C, vasoconstriction, is not a direct effect of beta-blockers; they actually cause vasodilation. D, reduction of renin release, is correct as beta-blockers inhibit renin-angiotensin system activity. Therefore, B is the exception among the listed cardiovascular effects of beta-receptor antagonists.
Question 4 of 5
Which stage of sleep is responsible for the incidence of dreams?
Correct Answer: A
Rationale: The correct answer is A: REM sleep. During REM (rapid eye movement) sleep, brain activity is high and resembles waking patterns. This stage is associated with vivid dreams. Slow wave sleep (choice B) is deep, restorative sleep with minimal dreaming. Stage 2 NREM sleep (choice C) is a lighter sleep stage with occasional light dreaming. Option D is incorrect because only REM sleep is widely recognized as the stage most responsible for dreaming due to increased brain activity and vivid dreams.
Question 5 of 5
Which of the following antiseizure drugs acts directly on the GABA receptor-chloride channel complex?
Correct Answer: B
Rationale: Step-by-step rationale: 1. Diazepam is a benzodiazepine that enhances GABAergic transmission by binding to GABA-A receptors. 2. GABA-A receptors are chloride channels that open in response to GABA binding. 3. By binding to GABA-A receptors, diazepam increases chloride influx, leading to neuronal hyperpolarization and inhibition of seizure activity. Summary: A. Vigabatrin inhibits GABA transaminase, increasing GABA levels indirectly. C. Gabapentin modulates calcium channels and has no direct effect on GABA receptors. D. Valproate increases GABA levels but does not directly bind to GABA receptors.