Which of the following is true regarding the cervix during pregnancy?

Correct Answer: B

Rationale: The correct answer is B: It forms a mucous plug to protect the uterus. During pregnancy, the cervix produces a thick mucus plug that seals the opening of the uterus, providing a barrier against infections and protecting the developing fetus. This plug helps prevent bacteria from entering the uterus and causing harm. Choice A is incorrect because the cervix actually closes during pregnancy to protect the developing fetus from infections. Choice C is incorrect because while the cervix may respond to hormonal changes during pregnancy, it does not secrete estrogen to prepare the uterus. Choice D is incorrect because the production of progesterone during pregnancy primarily occurs in the ovaries and the placenta, not the cervix.

Correct Answer: A

Rationale: Estrogen is the correct answer as it plays a crucial role in regulating the menstrual cycle. It promotes the growth of the uterine lining and stimulates ovulation. Progesterone works in conjunction with estrogen but is primarily involved in preparing the uterus for potential pregnancy. FSH and LH are both involved in the regulation of the menstrual cycle, but they primarily stimulate the development of follicles and ovulation, respectively. Estrogen, however, is the hormone that has a direct and central role in orchestrating the entire menstrual cycle by controlling various processes like follicle development, ovulation, and the thickening of the uterine lining.

Correct Answer: C

Rationale: The pituitary gland in the male reproductive system secretes follicle-stimulating hormone (FSH) and luteinizing hormone (LH) to regulate sperm production. FSH stimulates sperm production in the testes, while LH stimulates the production of testosterone by the Leydig cells. This hormonal regulation is essential for maintaining proper sperm production and male reproductive function. Choices A and D are incorrect because the pituitary gland does not secrete estrogen or testosterone directly. Choice B is incorrect because sperm production is not directly produced by the pituitary gland but is regulated by the hormones it secretes.

Correct Answer: B

Rationale: The correct answer is B: Estrogen. Estrogen is primarily responsible for regulating the menstrual cycle in females by stimulating the growth of the uterine lining. It also plays a key role in ovulation. FSH stimulates the growth of ovarian follicles, LH triggers ovulation, and Progesterone helps maintain the uterine lining after ovulation. However, Estrogen is the main hormone that drives the menstrual cycle's key phases.

Correct Answer: A

Rationale: Estrogen is the correct answer as it stimulates the growth of the uterine lining during the menstrual cycle. Estrogen is produced by the ovaries and peaks around ovulation, promoting the thickening of the endometrium to prepare for potential implantation. Progesterone, on the other hand, helps maintain the uterine lining after it has been thickened by estrogen. FSH and LH are involved in follicle development and ovulation, respectively, but they do not directly stimulate uterine lining growth.