ATI RN
Endocrine System MCQ Questions Questions
Question 1 of 5
The most appropriate drug for treating myasthenia gravis is:
Correct Answer: A
Rationale: Neostigmine is the correct choice for treating myasthenia gravis as it is an acetylcholinesterase inhibitor that increases acetylcholine levels, improving muscle strength. Pilocarpine is a muscarinic agonist used for glaucoma. Succinylcholine is a depolarizing neuromuscular blocker used for intubation. Tubocurarine is a non-depolarizing neuromuscular blocker.
Question 2 of 5
There are two simple ways to lower blood pressure: (1) reduce the cardiac contractility, and (2) inhibit sympathetic-mediated vasoconstriction. Which one of the following drugs can lower blood pressure by both mechanisms?
Correct Answer: C
Rationale: Rationale: Labetalol is a non-selective beta-blocker that reduces cardiac contractility by blocking beta-1 receptors and inhibits sympathetic-mediated vasoconstriction by blocking alpha-1 receptors. Albuterol (A) is a beta-2 agonist, which increases cardiac contractility. Atropine (B) is a muscarinic antagonist, which increases heart rate and does not affect vasoconstriction. Isoproterenol (D) is a non-selective beta agonist, which increases cardiac contractility and vasodilation. Thus, C (Labetalol) is the only drug that can lower blood pressure by both mechanisms.
Question 3 of 5
Some medications for relief of cold/allergy symptoms contain pseudoephedrine, which acts as a decongestant. If a patient who is taking an MAO inhibitor takes pseudoephedrine, what is the likely outcome?
Correct Answer: B
Rationale: Step 1: MAO inhibitors prevent the breakdown of neurotransmitters like norepinephrine. Step 2: Pseudoephedrine stimulates the release of norepinephrine. Step 3: The combination can lead to excessive norepinephrine, causing hypertension and potential stroke. Therefore, the likely outcome when a patient taking an MAO inhibitor also takes pseudoephedrine is a hypertensive crisis and possible stroke (Choice B). Summary: - Choice A (acute bronchospasm/asthma due to ACh release from the adrenal medulla) is incorrect because pseudoephedrine does not directly cause this response. - Choice C (heart rate and contractile force would drop significantly and quickly) is incorrect as pseudoephedrine tends to increase heart rate and blood pressure. - Choice D (the cold symptoms would quickly get worse - increased secretions) is incorrect as pseudoephedrine is a decongestant and would not worsen cold symptoms
Question 4 of 5
If the male labelled X is later mated to a black female, what ratio of coat colour would be expected in the offspring?
Correct Answer: D
Rationale: The male labeled X must carry both brown and black coat color genes as it is brown. When mated with a black female, the male will pass on either a brown or black gene to the offspring. This results in a 1:1 ratio of brown to black coat color in the offspring. All black (A) and all brown (B) are incorrect as the male carries both genes. The 3:1 ratio (C) is not applicable here as the male can pass on either brown or black gene equally.
Question 5 of 5
Which colour change is observed when water is added to anhydrous cobalt(II) chloride?
Correct Answer: B
Rationale: The correct answer is B: blue to pink. Anhydrous cobalt(II) chloride is blue, and when water is added, it forms a pink hexahydrate complex. This color change occurs because water molecules replace the chloride ions in the crystal lattice, resulting in the formation of the pink complex. Choice A (blue to white) is incorrect because the addition of water does not change the color to white. Choice C (white to blue) is incorrect as anhydrous cobalt(II) chloride is blue to begin with. Choice D (pink to blue) is incorrect as the addition of water causes the color change from blue to pink, not the other way around.