What is the primary purpose of the hormone oxytocin during labor?

Correct Answer: A

Rationale: Step 1: Oxytocin is known as the "love hormone" and plays a crucial role in uterine contractions. Step 2: During labor, oxytocin is released to stimulate rhythmic contractions of the uterus. Step 3: These contractions help to push the baby through the birth canal. Step 4: Therefore, the primary purpose of oxytocin during labor is to stimulate uterine contractions for the progression of labor. Summary: Choice A is correct because oxytocin's main function during labor is to stimulate uterine contractions. Choices B, C, and D are incorrect as oxytocin does not inhibit contractions, increase progesterone production, or directly prepare the cervix for dilation during labor.

Correct Answer: C

Rationale: The correct answer is C because the fallopian tubes transport the ovum from the ovary to the uterus for fertilization. This is their primary function in the reproductive system. Choice A is incorrect because the ovaries produce eggs, not the fallopian tubes. Choice B is incorrect as the fallopian tubes do not transport sperm but rather the egg. Choice D is also incorrect because estrogen is produced by the ovaries and other tissues, not by the fallopian tubes. In summary, the fallopian tubes serve as a pathway for the ovum to travel from the ovary to the uterus for potential fertilization.

Correct Answer: C

Rationale: Estrogen's primary function is to stimulate the development of female secondary sexual characteristics such as breast development and widening of the hips. This is crucial for the maturation of the female reproductive system. Estrogen does not directly regulate ovulation (choice A), support pregnancy (choice B), or control the menstrual cycle (choice D). Ovulation is mainly regulated by luteinizing hormone and follicle-stimulating hormone, pregnancy is supported by progesterone, and the menstrual cycle is under the control of various hormones including estrogen and progesterone.

Correct Answer: B

Rationale: The main function of the testes in males is to produce sperm. Sperm production, known as spermatogenesis, occurs within the seminiferous tubules of the testes. Testosterone is primarily secreted by the Leydig cells in the testes, not the main function. Storing sperm is not a primary function, as sperm is continuously produced and released. Transporting sperm is mainly done by the vas deferens, not the testes themselves. Therefore, the correct answer is B, as it directly relates to the primary function of the testes in males.

Correct Answer: B

Rationale: The correct answer is B: FSH. The pituitary gland produces follicle-stimulating hormone (FSH), which plays a key role in reproductive functions. FSH stimulates the growth and maturation of ovarian follicles in females and sperm production in males. A: Progesterone is produced by the ovaries and placenta in females. C: Estrogen is produced by the ovaries and adrenal glands in females. D: Testosterone is produced by the testes in males and in smaller amounts by the ovaries and adrenal glands in females.