Which of the following antidiabetic drugs act by blocking ATP sensitive K+ channels?

Correct Answer: D

Rationale: The correct answer is D because both Tolbutamide (A) and Repaglinide (B) act by blocking ATP sensitive K+ channels on pancreatic beta cells, leading to insulin secretion. Tolbutamide is a sulfonylurea, while Repaglinide is a meglitinide. Ciglitazone (C) is a thiazolidinedione that works by increasing insulin sensitivity in peripheral tissues, not by blocking ATP-sensitive K+ channels. Therefore, choices A, B, and C are incorrect as they do not directly block ATP-sensitive K+ channels.

Correct Answer: C

Rationale: The correct answer is C: Chlorpropamide. It is a sulfonylurea drug that can be used to treat Diabetes insipidus by increasing the release of antidiuretic hormone (ADH) from the pituitary gland, thereby reducing excessive urination. Voglibose (A) is an alpha-glucosidase inhibitor used for diabetes mellitus. Metformin (B) is a biguanide used for type 2 diabetes. Pioglitazone (D) is a thiazolidinedione also used for type 2 diabetes but not for Diabetes insipidus.

Correct Answer: A

Rationale: The correct answer is A: seminiferous tubules. Sperm production begins in the seminiferous tubules of the testes through a process called spermatogenesis. This is where immature germ cells called spermatogonia undergo multiple divisions to eventually form mature sperm cells. The other choices, B: epididymis, C: vas deferens, and D: ejaculatory duct, are incorrect as they are not sites of sperm production but rather play roles in sperm maturation, storage, and transportation during ejaculation.

Correct Answer: A

Rationale: The correct answer is A: endometrium. The endometrium is the innermost layer of the uterine wall that thickens in preparation for potential implantation of a fertilized egg. If fertilization does not occur, this layer is shed during menstruation. The myometrium (B) is the middle layer responsible for uterine contractions during labor. Epimetrium (C) is not a recognized term relating to the uterine wall. Choice D is incorrect as the endometrium is indeed the layer that sheds during menstruation.

Correct Answer: B

Rationale: The correct answer is B: cervix. The cervix is the structure between the uterus and the vagina. It functions as a passageway for sperm to travel to the uterus and for menstrual blood to flow out of the uterus. The other choices are incorrect because: A: Uterine tube (fallopian tube) connects the ovary to the uterus, not between the uterus and vagina. C: Vulva refers to the external genitalia, not the internal structure between the uterus and vagina. D: Hymen is a thin membrane at the vaginal opening, not the structure between the uterus and vagina.