Quinidine is a drug used for arrhythmias. One of its properties is strong postsynaptic alpha-adrenergic receptor blocking activity. What side effect would you expect as a result of this property?

Correct Answer: C

Rationale: The correct answer is C: Reduced blood pressure, hypotension. Quinidine's strong postsynaptic alpha-adrenergic receptor blocking activity would result in decreased activation of these receptors, leading to vasodilation and reduced blood pressure, which can cause hypotension. Choice A is incorrect because lacrimal and mucus secretions are not directly affected by alpha-adrenergic receptor blocking. Choice B is incorrect as dilated pupils are more associated with alpha-1 adrenergic receptor blockade. Choice D is incorrect as skeletal muscle tremors are not a typical side effect of alpha-adrenergic receptor blocking.

Correct Answer: C

Rationale: When aqueous silver nitrate is added to a mixture, a yellow precipitate forms if there are chloride ions present. This is due to the formation of silver chloride, which is insoluble in water. The reaction is AgNO3 + Cl- → AgCl↓ + NO3-. Therefore, choice C is correct. Choice A (white precipitate) is incorrect because silver chloride is yellow, not white. Choice B (white solution) is incorrect as a precipitate forms, not a solution. Choice D (yellow solution) is incorrect because the product is a solid precipitate, not a solution.

Correct Answer: C

Rationale: The correct answer is C: kidneys. The kidneys are not considered a major endocrine organ, but they do produce hormones such as erythropoietin and renin as part of their major function of regulating fluid balance and blood pressure. The pancreas (A) is a major endocrine organ producing insulin and glucagon. The thymus (B) is involved in immune function and produces hormones like thymosin. The pituitary (D) is often referred to as the master gland and secretes various hormones that regulate other endocrine glands.

Correct Answer: B

Rationale: The correct answer is B: DNA. Hormone response elements are specific DNA sequences where hormone receptors bind to regulate gene expression. This binding initiates the transcription of target genes. Choices A, C, and D are incorrect because hormone response elements are not located on the cell membrane, RNA, or enzymes. The key is understanding that hormone receptors act on DNA to regulate gene expression, making choice B the most appropriate answer.

Correct Answer: B

Rationale: The correct answer is B: Inferior phrenic artery. The superior suprarenal artery arises from the inferior phrenic artery, which supplies blood to the adrenal gland. The inferior phrenic artery originates from the abdominal aorta, near the celiac trunk. It is important to note that the adrenal glands receive blood supply from multiple sources, including the inferior phrenic artery. The other choices (A: Abdominal aorta, C: Renal artery, D: Superior mesenteric artery) do not directly supply blood to the adrenal glands, making them incorrect options.