What hormone(s) stimulates the growth of the endometrium during the proliferative phase of the uterine (menstrual) cycle?

Correct Answer: A

Rationale: Estrogens stimulate growth of the endometrium during the proliferative phase by promoting cell proliferation and thickening of the endometrial lining. Estrogens also increase blood flow to the endometrium. Progesterone, on the other hand, prepares the endometrium for implantation and supports pregnancy, but does not directly stimulate growth during the proliferative phase. Insulin and testosterone do not have direct roles in stimulating endometrial growth during this phase.

Correct Answer: B

Rationale: The correct answer is B: bulbo-urethral glands. These glands secrete a milky-colored fluid called pre-ejaculate or Cowper's fluid, which lubricates the urethra and neutralizes any acidic urine residue to protect sperm. The other choices are incorrect because the epididymis (A) stores and matures sperm, the prostate (D) secretes a milky fluid that nourishes and protects sperm, and option C is incomplete.

Correct Answer: D

Rationale: The correct answer is D: ectoderm. The primary germ layer that gives rise to structures like the lacrimal glands is the ectoderm, which is one of the three primary germ layers during embryonic development. The ectoderm gives rise to tissues such as the epidermis of the skin, nervous system, and various glands including lacrimal glands. Choice A, areolar glands to the mucosae and associated glands, is incorrect as they are derived from the mesoderm. Choice C, sweat glands, is also incorrect as they are derived from the ectoderm but are not the primary germ layer responsible for lacrimal glands. Choice B, lacrimal glands is the _______, is incorrect as it does not provide a complete statement and is not a primary germ layer.

Correct Answer: A

Rationale: The correct answer is A: acrosome, flagellum, nucleus. The acrosome contains enzymes for penetrating the egg. The flagellum is the tail for movement. The nucleus contains genetic material. Choice B is incorrect because a codpiece is a protective garment and not a component of sperm. Choice C is incorrect because seminal vesicles and mitochondria are not components of sperm. Choice D is incorrect because efferent ductules are part of the male reproductive system, not a component of sperm.

Correct Answer: A

Rationale: Inhibin is secreted by Sertoli cells to inhibit follicle stimulating hormone (FSH) from the anterior pituitary. This is the correct answer because inhibin acts as a negative feedback mechanism to regulate FSH levels in the body. Sertoli cells are specifically involved in spermatogenesis and play a crucial role in regulating FSH secretion through inhibin. Choices B, C, and D are incorrect because inhibin does not inhibit testosterone secretion or act on Leydig cells. It specifically targets FSH secretion to regulate the process of spermatogenesis.