Which hormone initiates the changes in puberty?

Correct Answer: D

Rationale: The correct answer is D: GnRH. Gonadotropin-releasing hormone (GnRH) is released from the hypothalamus, stimulating the pituitary gland to produce FSH and LH, which then trigger the changes of puberty. FSH and LH are not the initial hormones that start puberty, but rather the result of GnRH stimulation. Testosterone and ICSH are also involved in puberty but are not the primary hormone that initiates the process.

Correct Answer: A

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: The correct answer is B: endometrium. After fertilization, the blastocyst travels through the uterine tubes and implants into the endometrium for further development. The endometrium is the inner lining of the uterus where implantation occurs to establish pregnancy. The uterine tubes (choice A) are the site of fertilization, but not implantation. The cervix (choice C) is the lower part of the uterus that connects to the vagina and does not play a role in implantation. The ovary (choice D) is where the egg is released during ovulation and not the site of implantation.

Correct Answer: A

Rationale: The correct answer is A: Mesonephric duct. The Wolffian duct is also known as the mesonephric duct because it develops in the embryo to form the male reproductive system. It gives rise to various structures such as the epididymis, vas deferens, and seminal vesicles. The other choices are incorrect because the ejaculatory duct is formed by the union of the vas deferens and seminal vesicle, the major sublingual duct is associated with saliva production, and the cystic duct is part of the biliary system and not related to the male reproductive system.

Correct Answer: D

Rationale: The correct answer is D: Ejaculatory duct. This structure is formed by the union of the duct from the seminal vesicle and the ampulla of the vas deferens. The ejaculatory duct plays a crucial role in male reproductive anatomy by transporting sperm and seminal fluid to the urethra for ejaculation. The other choices (A: Urethra, B: Spermatic cord, C: Inguinal canal) are incorrect because they do not involve the specific union of the duct from the seminal vesicle and the ampulla of the vas deferens, which is unique to the ejaculatory duct. The urethra is the final pathway for semen release, the spermatic cord contains blood vessels and nerves that supply the testicles, and the inguinal canal is a passage for structures like blood vessels and nerves to pass through the abdominal wall.