Which one of the following hormones is not a placental hormone.

Correct Answer: A

Rationale: The correct answer is A: oxytocin. Oxytocin is not a placental hormone because it is produced by the hypothalamus and stored in the posterior pituitary gland. Placental hormones are specifically produced by the placenta during pregnancy. Relaxin, estrogen, and human chorionic gonadotropin hormone are all placental hormones involved in various functions during pregnancy. Oxytocin, on the other hand, plays a role in uterine contractions during labor and milk ejection during breastfeeding, but it is not produced by the placenta.

Correct Answer: A

Rationale: The correct answer is A: Vagina. The vagina is the muscular passageway from the cervix to the outside of the female's body, serving as the birth canal. It is where sexual intercourse occurs and where menstrual flow exits the body. The uterus (B) is the organ where a fertilized egg implants and develops into a fetus, not the birth canal. Fallopian tubes (C) are where fertilization of an egg typically occurs, not part of the birth canal. Obstetrician (D) is a medical professional specializing in childbirth and pregnancy, not a part of the female reproductive anatomy.

Correct Answer: C

Rationale: The correct answer is C: Implantation. After fertilization, the embryo travels through the fallopian tube and reaches the uterus. During implantation, the embryo attaches itself to the endometrium lining of the uterus for further development. Menopause (A) is the cessation of menstrual cycles, ovulation (B) is the release of an egg from the ovary, and menstruation (D) is the shedding of the uterine lining if fertilization does not occur.

Correct Answer: B

Rationale: The correct answer is B: inside the scrotum. The testicles are located outside the abdominal cavity in a structure called the scrotum. This location is essential for temperature regulation as sperm production requires a slightly lower temperature than the body's core. Choices A, C, and D are incorrect as the testicles are not inside a muscular pouch, at the inguinal canal, or inside the abdominal cavity.

Correct Answer: B

Rationale: The correct answer is B because the seminal vesicle is indeed a pair organ, meaning there are two of them in the male reproductive system. They are located posterior to the urinary bladder and are responsible for producing and secreting a significant portion of the seminal fluid. Choice A is incorrect because the seminal vesicles are located behind the bladder, not above the prostate. Choice C is incorrect as the seminal vesicles are located laterally, not medially from the deferent ducts. Choice D is incorrect because the seminal vesicle is not an endocrine organ; it has an exocrine function in producing seminal fluid.