The male reproductive system arises from

Correct Answer: B

Rationale: The correct answer is B: Mesonephric (Wolffian) ducts. The male reproductive system arises from the mesonephric ducts, which develop into structures like the epididymis, vas deferens, and seminal vesicles. The mesonephric ducts are responsible for transporting sperm from the testes to the urethra. The other choices are incorrect because A (Paramesonephric ducts) develop into the female reproductive system, C (FSH) is a hormone involved in the regulation of reproductive processes but does not directly give rise to the male reproductive system, and D (aldosterone) is a hormone involved in electrolyte balance and has no role in male reproductive system development.

Correct Answer: D

Rationale: The correct answer is D: Human chorionic gonadotropin (hCG). This hormone is released from the placenta during pregnancy and is essential for maintaining the corpus luteum, which in turn produces progesterone to support the pregnancy. hCG is also the hormone detected in pregnancy tests. Choice A (Follicle stimulating hormone) and B (Luteinizing hormone) are involved in the menstrual cycle, not specifically released from the placenta. Choice C (Estrogen) is produced by the ovaries and not directly released from the placenta.

Correct Answer: C

Rationale: The correct answer is C: Eunuch. When a male is castrated before puberty, he becomes a eunuch because castration removes the testes, leading to a lack of testosterone production and loss of male secondary sexual characteristics. This results in a eunuch having a more neutral appearance and lacking the ability to reproduce. A: Choosing "Female" is incorrect because castration does not change the individual's genetic sex. B: Selecting "Cretin" is incorrect as cretinism is a condition caused by severe thyroid hormone deficiency, not related to castration. D: Opting for "Potent" is incorrect as castration leads to the loss of reproductive ability, making the individual infertile.

Correct Answer: C

Rationale: The correct answer is C: Abdominal cavity. During embryonic development, the male gonads (testes) initially form in the abdominal cavity near the kidneys. They then descend through the inguinal canal into the scrotum. The pelvic cavity (choice A) is below the abdominal cavity, the peritoneal cavity (choice B) is a part of the abdominal cavity, and the cul-de-sac (choice D) is a pouch in the pelvic cavity. The key point is understanding the anatomical path of descent of the male gonads from the abdominal cavity to the scrotum.

Correct Answer: B

Rationale: The correct answer is B: Torticollis. Spasm of the sternocleidomastoid muscle in the neck causes the head to tilt to one side and the chin to rotate to the opposite side, leading to a condition known as torticollis. Talipes equinovarus (A) is a foot deformity, cleft lip (C) is a congenital facial anomaly, and kyphosis (D) is an abnormal curvature of the spine. These conditions are not directly related to the spasm of the sternocleidomastoid muscle in the neck.