What is the role of oxytocin in childbirth?

Correct Answer: B

Rationale: The correct answer is B: Stimulate uterine contractions. Oxytocin is a hormone that plays a key role in initiating and maintaining labor by stimulating uterine contractions. It acts on the smooth muscles of the uterus to promote the rhythmic contractions necessary for childbirth. Oxytocin also helps with the ejection of milk during breastfeeding but its primary role in childbirth is to stimulate uterine contractions. Incorrect choices: A: Inhibit uterine contractions - This is incorrect as oxytocin actually stimulates, not inhibits, uterine contractions. C: Increase milk production - While oxytocin does play a role in milk ejection during breastfeeding, its primary role in childbirth is to stimulate uterine contractions. D: Prepare the cervix for dilation - While oxytocin may contribute to cervical dilation during labor, its primary role is in stimulating uterine contractions.

Correct Answer: B

Rationale: Progesterone's role in the female reproductive system is to prepare the uterus for implantation by thickening the uterine lining. This is essential for successful implantation of a fertilized egg. Progesterone does not stimulate ovulation (which is mainly regulated by luteinizing hormone), prevent pregnancy (contraceptives containing progesterone are used for this purpose), or promote the development of secondary sexual characteristics (which is primarily the role of estrogen).

Correct Answer: B

Rationale: The acrosome in sperm contains enzymes that help the sperm penetrate the outer layer of the egg during fertilization. This process is crucial for successful fertilization. The other choices are incorrect because: A) Energy for sperm comes from mitochondria, not the acrosome. C) Sperm are stored in the epididymis, not the acrosome. D) Genetic material is stored in the nucleus of the sperm cell, not the acrosome. Therefore, the correct answer is B as the acrosome's function is directly related to the penetration of the egg during fertilization.

Correct Answer: A

Rationale: The correct answer is A: Increased cervical mucus. During ovulation, the body produces more cervical mucus that becomes clear, stretchy, and slippery to facilitate sperm movement. This helps in the fertilization process. Lower body temperature and decreased estrogen levels are not typically signs of ovulation. Thickening of the uterine lining occurs during the menstrual cycle in preparation for a potential pregnancy, not specifically during ovulation.

Correct Answer: A

Rationale: The correct answer is A: Seminal vesicles. Seminal vesicles are responsible for producing seminal fluid, which makes up the majority of semen. They secrete a fluid rich in fructose and other nutrients to provide energy for sperm. The other choices are incorrect because the prostate gland produces a milky fluid that aids in sperm motility but is not the primary producer of seminal fluid. The epididymis stores and transports sperm, and the testes produce sperm cells through spermatogenesis, but neither of these structures is responsible for producing seminal fluid.