The nurse is teaching assistive personnel (AP) about hormones that are produced by the adrenal glands. Which hormone has the primary responsibility of maintaining fluid volume and electrolyte composition?

Correct Answer: C

Rationale: The correct answer is C: Aldosterone. Aldosterone is a hormone produced by the adrenal glands that plays a crucial role in maintaining fluid volume and electrolyte composition by regulating sodium and potassium levels in the body. It promotes sodium reabsorption and potassium excretion in the kidneys, helping to maintain blood pressure and electrolyte balance. Therefore, aldosterone has the primary responsibility for maintaining fluid volume and electrolyte composition. A: Sodium - While sodium is an important electrolyte involved in fluid balance, it is not a hormone produced by the adrenal glands. B: Magnesium - Magnesium is also an important electrolyte, but it is not primarily responsible for maintaining fluid volume and electrolyte composition in the body. D: Renin - Renin is an enzyme produced by the kidneys that plays a role in regulating blood pressure and fluid balance, but it is not a hormone produced by the adrenal glands and does not have the primary responsibility for maintaining fluid volume and electrolyte composition.

Correct Answer: B

Rationale: The correct answer is B: Norepinephrine. When an antagonist at ganglionic nicotinic receptors is administered, it blocks the inhibitory effect on sympathetic tone. Since norepinephrine is a sympathetic neurotransmitter that increases blood pressure and heart rate, it is likely that Drug X is norepinephrine. Propranolol (A) is a beta-blocker that decreases heart rate, Isoproterenol (C) is a beta-agonist that increases heart rate, and Terbutaline (D) is a beta-agonist that also increases heart rate. These choices do not align with the observed effects of Drug X when the ganglionic nicotinic receptor antagonist is administered.

Correct Answer: B

Rationale: The correct answer is B. Pirenzepine is NOT preferred over propantheline in the treatment of intestinal colic because pirenzepine is a selective M1 receptor antagonist used for peptic ulcer disease, while propantheline is an anticholinergic used for GI spasms. Choice A is incorrect because atropine is preferred over hyoscine in thyrotoxic patients due to its faster onset. Choice C is incorrect because ipratropium is not necessarily better than atropine in bronchial asthma as they have different mechanisms of action. Choice D is incorrect because atropine is actually preferred over tropicamide for fundus examination due to its longer duration of action.

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.

Correct Answer: D

Rationale: Hyoscine, also known as scopolamine, is an anticholinergic drug that acts by blocking muscarinic receptors. It produces sedation by crossing the blood-brain barrier and affecting the central nervous system. Its antiemetic action is due to its ability to inhibit the vomiting center in the brain. Stimulation of the respiratory center is not a typical action of hyoscine. Lastly, hyoscine decreases salivary secretion due to its anticholinergic effects. Therefore, the correct answer is D (Increase of salivary secretion) as it is inconsistent with the pharmacological actions of hyoscine.