The seminal vesicle secretes:

Correct Answer: C

Rationale: Step-by-step rationale: 1. The seminal vesicle secretes a fluid eliminated in the ejaculatory ducts. 2. This fluid provides nutrients and energy for the sperm. 3. It also helps to neutralize the acidic environment of the male urethra. 4. The fluid from the seminal vesicle combines with sperm to form semen for ejaculation. Summary: A: The seminal vesicle does not secrete androgenic hormones. B: Sperm cells are not secreted by the seminal vesicle. D: The seminal vesicle's fluid does not transport sperm cells; it provides support and nourishment for them.

Correct Answer: A

Rationale: Step 1: The cortical area of the ovary is the outer layer where follicles develop. Step 2: Primordial follicles are the earliest stage of follicle development, found in the cortex. Step 3: Mature follicles are developed follicles located deeper in the ovary, not in the cortex. Step 4: Secondary follicles are also more developed than primordial follicles, located deeper. Step 5: Blood vessels are important for supplying nutrients but are not specific to the cortical area. Therefore, the correct answer is A as primordial follicles are located in the cortical area, while other choices are found in different regions of the ovary.

Correct Answer: C

Rationale: The corpus luteum is formed from the ruptured follicle after ovulation. It secretes progesterone, which is crucial for preparing the uterus for implantation and maintaining early pregnancy. Progesterone helps thicken the uterine lining and supports embryo development. Estrogens are mainly produced by the ovaries, not the corpus luteum. Testosterone is primarily produced by the adrenal glands and testes, not the corpus luteum. Therefore, choice C is correct as it accurately describes the main hormone secreted by the corpus luteum.

Correct Answer: B

Rationale: The correct answer is B: the hypothalamus. The hypothalamus secretes gonadotropin-releasing hormone (GnRH) which stimulates the anterior pituitary to release follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which in turn regulate the secretion of ovarian hormones (estrogen and progesterone). The anterior pituitary secretes FSH and LH in response to GnRH from the hypothalamus. Therefore, the hypothalamus plays a crucial role in controlling the secretion of ovarian hormones. Choices A, C, and D are incorrect because the anterior pituitary releases FSH and LH but is not the primary controller, FSH is a hormone released by the anterior pituitary but is not the primary controller, and LH is released by the anterior pituitary but is not the primary controller of ovarian hormone secretion.

Correct Answer: D

Rationale: The correct answer is D because the placenta serves as a barrier between the maternal and fetal bloodstreams, allowing for the exchange of nutrients, oxygen, and waste products. This is crucial for the fetus's growth and development. Choice A is incorrect because the placenta does not physically surround the embryo. Choice B is incorrect as maternal and fetal blood do not mix due to the placental barrier. Choice C is incorrect as the heart of the fetus pumps blood, not the placenta.