Your 30 year old female patient is c/o bad-smelling vaginal discharge with mild itching for about 3 weeks. Douching did not help. Denies painful urination or intercourse. She noticed the smell increased after intercourse and during her period last week. There are no lesions on the perineum. No lymphadenopathy. On speculum examination, there is a thin gray-white discharge. The pH of the discharge is over 4.5 and there is a fishy odor when potassium hydroxide (KOH) is applied to the vaginal secretions on the slide. Wet prep shows epithelial cells with stippled border (clue cells). What type of vaginitis best describes the findings?

Correct Answer: C

Rationale: The correct answer is C: Bacterial vaginosis. The key findings in this scenario point towards bacterial vaginosis. The presence of thin gray-white discharge, fishy odor with KOH, pH over 4.5, and clue cells on wet prep are classic for bacterial vaginosis. Trichomonas vaginitis (choice A) typically presents with yellow-green frothy discharge and motile trichomonads on microscopy. Candida vaginitis (choice B) is characterized by thick, white, cottage cheese-like discharge and budding yeast or pseudohyphae on microscopy. Atrophic vaginitis (choice D) usually occurs in menopausal women due to estrogen deficiency and presents with thin, pale vaginal walls and vaginal dryness. In this case, the absence of these findings makes bacterial vaginosis the most likely diagnosis.

Correct Answer: D

Rationale: Step-by-step rationale: 1. After birth, the foramen ovale closes, reducing flow (A) 2. Pressure in the right atrium decreases due to closing of fetal shunts (B) 3. Ductus arteriosus closes, reducing flow (C) 4. Aortic pressure increases as systemic circulation begins (D) Summary: A, B, and C decrease after birth due to closure of fetal shunts, while D increases as systemic circulation takes over, making it the correct choice.

Correct Answer: B

Rationale: The correct answer is B, as RU486 blocks progesterone receptors, preventing progesterone from exerting its effects. Progesterone is crucial for maintaining the uterine lining to support a pregnancy. By blocking progesterone receptors, RU486 causes the uterine lining to break down, leading to the expulsion of the embryo and ultimately causing abortion. Choice A is incorrect because RU486 does not bind to luteinizing hormone receptors or stimulate progesterone secretion. Choice C is incorrect because RU486 does not block the secretion of follicle-stimulating hormone; its mechanism of action is specific to progesterone receptors. Choice D is incorrect because RU486 does not block the effects of oxytocin receptors in the uterine muscle; its primary action is on progesterone receptors.

Correct Answer: A

Rationale: The correct answer is A: An antibody that blocked the effect of human chorionic gonadotropin in the embryo and fetus. Human chorionic gonadotropin (hCG) is crucial for male sexual differentiation. Blocking its effects would lead to the development of female genital organs in pups with XY chromosomes. Estrogen-like compounds (B) and follicle-stimulating hormone (C) are not directly involved in male sexual differentiation. Testosterone (D) is responsible for male sexual development, so giving testosterone would not result in female genital organs in XY pups.

Correct Answer: A

Rationale: Step 1: High levels of gamma radiation cause destruction of germinal epithelium, leading to infertility. Step 2: Normal testosterone levels indicate intact Leydig cells, responsible for testosterone production. Step 3: Normal secretory pattern of gonadotropin-releasing hormone (GnRH) is expected as it regulates pituitary hormone secretion. Step 4: Inhibin is produced by Sertoli cells (part of germinal epithelium) and would be decreased due to destruction. Step 5: Follicle-stimulating hormone (FSH) levels would be elevated, not suppressed, due to lack of inhibin feedback. Step 6: Leydig cells are intact, so Leydig cells are not absent in this scenario.