Estrogen therapy can worsen the following associated conditions except:

Correct Answer: B

Rationale: Estrogen therapy can worsen conditions that are sensitive to hormonal fluctuations. Cholelithiasis (gallstones) is not influenced by estrogen levels, so it is not worsened by estrogen therapy. Migraine, acne vulgaris, and endometriosis are conditions known to be affected by estrogen levels and can potentially worsen with estrogen therapy. Therefore, the correct answer is B. Migraine can worsen due to estrogen's impact on blood vessels, acne vulgaris can worsen due to increased sebum production, and endometriosis can worsen due to estrogen's role in promoting tissue growth.

Correct Answer: A

Rationale: The correct answer is A: Tetracycline. Tetracycline can cause rickets in children by binding to calcium in bones, inhibiting bone growth. This interference with vitamin D action leads to impaired calcium absorption. Digoxin, Phenytoin, and Ciprofloxacin do not interfere with vitamin D metabolism or calcium absorption, ruling them out as potential causes of rickets in children.

Correct Answer: D

Rationale: The correct answer is D because parathormone receptors are expressed on the surface of osteoblasts, osteoclasts, and gut mucosal cells. Parathormone regulates calcium and phosphate levels in the body, influencing bone metabolism and intestinal absorption. Osteoblasts are bone-forming cells, osteoclasts are bone-resorbing cells, and gut mucosal cells are involved in calcium absorption. Therefore, parathormone receptors are present on all three cell types to coordinate calcium homeostasis. Choices A, B, and C are incorrect because parathormone receptors are not exclusive to any one cell type but are present on all three mentioned in the question.

Correct Answer: C

Rationale: The correct answer is C: Intravenous calcium gluconate. Tetany is caused by low levels of calcium in the blood. Calcium gluconate is the appropriate treatment as it quickly and effectively raises blood calcium levels. Diazepam (A) is a muscle relaxant, vitamin D (B) is used for bone health, and calcitonin (D) is used to regulate calcium and phosphate levels in the body, but they are not the primary treatment for tetany.

Correct Answer: A

Rationale: The correct answer is A (1-2 months) because fertility typically returns quickly after stopping the combined estrogen-progestin contraceptive pill. Estrogen and progestin hormones are quickly metabolized and cleared from the body, allowing the menstrual cycle to resume within a month or two. Choice B (4-6 months) is incorrect as fertility usually returns sooner. Choice C (6-12 months) is also incorrect as it is an extended timeframe for fertility to return. Choice D (Uncertain period) is incorrect as there is a general understanding of the timeline for fertility to return after stopping the pill.