Which hormone is necessary for the growth of endometrial glands, which are important for the sustenance of a growing embryo until its implantation?

Correct Answer: C

Rationale: The correct answer is C: Progesterone. Progesterone is necessary for the growth of endometrial glands as it prepares the endometrium for implantation of the embryo. LH is responsible for ovulation, not endometrial gland growth. Testosterone is a male sex hormone and not directly involved in endometrial gland growth. Inhibin regulates FSH secretion, not endometrial gland growth.

Correct Answer: D

Rationale: The spongy tissue of the penis fills with blood during an erection to cause the penis to become rigid. This process is essential for maintaining an erection during sexual activity. Spermatogenesis refers to the production of sperm, not the filling of spongy tissue. Circumcision does not involve the filling of spongy tissue with blood. Ejaculation is the release of semen and does not involve the filling of spongy tissue. Therefore, the correct answer is D as it accurately describes the physiological process of penile erection.

Correct Answer: D

Rationale: The correct answer is D: chorionic villi. Parturition occurs when the fetus releases cortisol, which stimulates the production of prostaglandins leading to uterine contractions. Chorionic villi are the fetal tissue that produces cortisol, making it the key factor triggering labor. A: Amnion is the innermost membrane around the fetus, not directly involved in labor initiation. B: Placenta plays a role in nutrient exchange but not in triggering labor. C: 180 days is a set time frame and does not relate to the process of parturition.

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: B

Rationale: The correct answer is B because it is incorrect to say that a male erection is triggered by motor inputs to the higher brain regions. Erections are primarily controlled by the autonomic nervous system, specifically the parasympathetic division. Parasympathetic activity leads to vasodilation of penile blood vessels, resulting in increased blood flow and erection. Choices A, C, and D are incorrect because during an erection, there is indeed an increase in parasympathetic activity, a decrease in sympathetic activity, and dilation of arterioles in the penis.