What type of glands are the glands of Moll?

Correct Answer: B

Rationale: The glands of Moll are a type of apocrine sweat glands located in the eyelids. They secrete a clear fluid that helps lubricate the eyes. The correct answer is B because apocrine glands are associated with hair follicles and produce a thicker secretion compared to eccrine sweat glands. Endocrine glands (A) secrete hormones into the bloodstream, oil glands (C) are associated with hair follicles and produce sebum, and sebaceous glands (D) are also oil-producing glands but are different from the glands of Moll.

Correct Answer: A

Rationale: The correct answer is A: Plasma levels of endogenous hormone are high. When the amount of radioactive hormone bound to the antibody is low in a radioimmunoassay, it indicates that there is a high concentration of non-radioactive, endogenous hormone present in the sample competing for binding sites on the antibody. This competition results in fewer radioactive hormones binding to the antibody. Therefore, the low radioactive hormone binding suggests an abundance of non-radioactive hormone in the sample. Choice B is incorrect because low levels of radioactive hormone binding do not indicate low plasma levels of endogenous hormone. Choice C is incorrect as more antibody wouldn't affect the binding of radioactive hormone if endogenous hormone levels are high. Choice D is incorrect because the amount of radioactive hormone needed is not related to the binding observed in the assay.

Correct Answer: A

Rationale: The correct answer is A because prostaglandin E2 (PGE2) is known to strongly stimulate uterine contractions. This can lead to abortion by triggering premature labor and causing the expulsion of the fetus. Choice B is incorrect as PGE2 does not cause arterial constriction leading to the placenta. Choice C is incorrect because PGE2 does not stimulate the release of oxytocin; rather, oxytocin itself is a hormone that stimulates uterine contractions. Choice D is also incorrect as PGE2 does not increase progesterone secretion from the corpus luteum; in fact, PGE2 can have the opposite effect by inhibiting progesterone synthesis.

Correct Answer: D

Rationale: The correct answer is D: Human chorionic gonadotropin (hCG). During the first 3 weeks of pregnancy, trophoblast cells produce hCG, which is crucial for maintaining the corpus luteum and ensuring the production of progesterone to support the early pregnancy. hCG is also the hormone detected in pregnancy tests. Rationale: A: Estrogen is mainly produced by the ovaries, not trophoblast cells in the early stages of pregnancy. B: Luteinizing hormone is produced by the pituitary gland to trigger ovulation, not by trophoblast cells. C: Oxytocin is produced by the hypothalamus and released by the pituitary gland during labor and breastfeeding, not by trophoblast cells in the early stages of pregnancy.

Correct Answer: A

Rationale: The correct answer is A: Below-normal arterial PO2. In a 12-month-old infant with patent ductus arteriosus, there would likely be a left-to-right shunt causing increased blood flow to the lungs, leading to decreased systemic blood flow. This can result in decreased systemic oxygenation and below-normal arterial PO2 levels. Choices B, C, and D are incorrect because patent ductus arteriosus does not directly affect arterial PCO2, arterial blood pressure, or pulmonary arterial pressure in a way that would lead to those specific outcomes at this age.