ATI RN
Endocrine System Test Questions Questions
Question 1 of 5
The action of acetylcholine is very short due to:
Correct Answer: D
Rationale: The correct answer is D: Hydrolysis by cholinesterase enzyme. Acetylcholine is broken down by cholinesterase enzyme into choline and acetate, leading to the termination of its action. Rapid hepatic metabolism (A) is not the primary mechanism for acetylcholine breakdown. Reuptake by nerve endings (B) refers to reuptake of neurotransmitters, not breakdown. Binding to plasma proteins (C) does not affect the duration of acetylcholine action.
Question 2 of 5
A child visiting his grandfather at his farm returns home having fever, skin flush, dry mouth, constipation, dilated pupils, and increased heart rate. Which of the following could be the offending agent:
Correct Answer: A
Rationale: The correct answer is A: Eating seeds containing atropine. Atropine is a plant alkaloid commonly found in certain seeds that can cause symptoms such as fever, skin flush, dry mouth, constipation, dilated pupils, and increased heart rate when ingested. Atropine is known to have anticholinergic effects, which align with the symptoms presented by the child. Malathion (B) is an insecticide that typically causes different symptoms like nausea, vomiting, and diarrhea. Echothiophate drops (C) are cholinesterase inhibitors used in the treatment of glaucoma, which would not produce the described symptoms. Physostigmine (D) is a cholinesterase inhibitor that would not cause symptoms of anticholinergic toxicity seen in the child.
Question 3 of 5
Anti-cholinesterase drugs include the following drugs EXCEPT:
Correct Answer: B
Rationale: The correct answer is B: Carbachol. Anti-cholinesterase drugs inhibit the enzyme acetylcholinesterase, increasing levels of acetylcholine. Carbachol is a direct cholinergic agonist, not an anti-cholinesterase drug. Physostigmine, Metrifonate, and Neostigmine are all anti-cholinesterase drugs that work by inhibiting acetylcholinesterase. Physostigmine is used for glaucoma and atropine overdose, Metrifonate for parasitic infections, and Neostigmine for myasthenia gravis.
Question 4 of 5
Which of the following is an alpha-blocker used in the treatment of hypertension:
Correct Answer: B
Rationale: Step 1: Understand the question is about an alpha-blocker for hypertension. Step 2: Identify Prazosin as an alpha-blocker used for hypertension by blocking alpha-1 receptors. Step 3: Explain how Prazosin works to dilate blood vessels and lower blood pressure. Step 4: Summarize why other choices are incorrect: - A: Tyramine is not an alpha-blocker, it is found in certain foods. - C: Ergometrine is an ergot alkaloid used for uterine contractions, not hypertension. - D: Ergotamine is also an ergot alkaloid used for migraines, not hypertension.
Question 5 of 5
Nitroglycerin is a vasodilator used in the treatment of angina. A common side effect of its vasodilator activity is a reflex increase in heart rate, which is sometimes dangerous. Which drug could inhibit this reflex cardiac stimulation?
Correct Answer: D
Rationale: The correct answer is D: Propranolol. Propranolol is a beta-blocker that blocks the beta-adrenergic receptors in the heart, preventing the reflex increase in heart rate caused by nitroglycerin. This action helps to counteract the potentially dangerous side effect of increased heart rate. A: Atropine is not the correct answer because it is an anticholinergic drug that increases heart rate, which would exacerbate the reflex cardiac stimulation caused by nitroglycerin. B: Cocaine is a stimulant drug that can further increase heart rate and is not used to inhibit reflex cardiac stimulation. C: Phentolamine is an alpha-blocker that primarily acts on alpha-adrenergic receptors and is not the preferred drug for inhibiting the reflex increase in heart rate caused by nitroglycerin.