ATI RN
Chapter 17 Endocrine System Test Questions Questions
Question 1 of 5
All of the following are β-adrenergic agonists EXCEPT:
Correct Answer: D
Rationale: Failed to generate a rationale of 500+ characters after 5 retries.
Question 2 of 5
Atropine is used clinically in all of the following conditions EXCEPT:
Correct Answer: D
Rationale: Certainly! Atropine is an anticholinergic drug that works by blocking the action of acetylcholine. Xerostomia (dry mouth) is a symptom caused by decreased salivary gland activity, so using atropine would exacerbate this condition. In contrast, atropine is used in pre-anesthetic medication to reduce secretions, in organic phosphate poisoning to counteract the cholinergic effects, and in intestinal colic to relax smooth muscles. Therefore, the correct answer is D because atropine would worsen dry mouth.
Question 3 of 5
In relation to the molecular mechanism of action of sympathomimetics, the following is CORRECT:
Correct Answer: D
Rationale: The correct answer is D: Alpha 1 receptor stimulation releases IP3 and DAG. When alpha 1 receptors are stimulated by sympathomimetics, they activate G-proteins which then stimulate phospholipase C. Phospholipase C cleaves phosphatidylinositol 4,5-bisphosphate (PIP2) into inositol trisphosphate (IP3) and diacylglycerol (DAG). IP3 triggers the release of calcium from intracellular stores, leading to smooth muscle contraction, while DAG activates protein kinase C to initiate various cellular responses. Choices A, B, and C are incorrect because beta receptor stimulation increases cAMP, alpha 2 receptor stimulation inhibits adenyl cyclase leading to decreased cAMP levels, and alpha 2 receptor stimulation does not increase cAMP.
Question 4 of 5
Concerning catecholamines, all the following are true EXCEPT:
Correct Answer: D
Rationale: The correct answer is D because ephedrine and amphetamine are not catecholamines. A is correct as catecholamines contain a catechol nucleus. B is true as they act directly on receptors. C is also true since catecholamines have a short duration of action. Therefore, D is the incorrect statement as ephedrine and amphetamine do not fall under the category of catecholamines due to their chemical structure and mode of action.
Question 5 of 5
Propranolol is contraindicated in:
Correct Answer: B
Rationale: Propranolol is a non-selective beta-blocker that can cause bronchoconstriction, making it contraindicated in bronchial asthma. It can worsen asthma symptoms by blocking beta-2 receptors in the lungs. Angina pectoris, hypertension, and arrhythmia are conditions where propranolol is commonly used due to its beta-blocking effects on the heart and blood vessels.