Females' ovaries secrete estrogen, testosterone, and progesterone. Estrogen has many functions, including development of female secondary sex characteristics. Such charactersistics include, but are not limited to: development of breast tissue, redistribution of body fat to the hips, thighs, buttocks, and breasts, and initiation of menses. In females, testosterone functions primarily to increase sexual arousal. Progesterone, luteinizing hormone, and follicle-stimulating hormone play roles in the menstrual cycle. The corpus luteum is formed from the follicle and remains in the ovary after the egg has been released. It secretes progesterone for about two weeks, then deteriorates in the absence of a pregnancy.

The male gonads, the testes, are responsible development and maturation of sperm and secretion of testosterone. Ovaries and fallopian tubes can be ruled out because they are found only in females, and thus do not contribute to the development of sperm. The prostate gland does not produce sperm, rather it secretes fluid that nourishes and protects sperm. The bulbourethral gland aids in the process of ejaculation.

The anterior pituitary gland produces both FSH and LH, two hormones that play key roles in the menstrual cycle. The hypothalamus produces several tropic hormones and is responsible for maintaining homeostatis of the body via the endocrine system. The thyroid gland determines metabolic rate. The prostate gland does not produce any hormones. The uterus does not produce these two hormones; however, since LH and FSH regulate the menstrual cycle, events in the uterus are indirectly influenced by FSH and LH. 

At the midpoint of the 28-day menstrual cycle, ovulation occurs. This involves the realease of one mature egg from the follicle in one ovary. Fertilization refers to the fusion of the nuclei of a sperm and an egg, resulting in a zygote. Menstruation occurs at the beginning of the menstrual cycle, around days 2-7. Gestation refers to the period marked by pregnancy. During the time of ovulation, progesterone levels are gradually rising, preparing the uterus for reception of the implanted zygote.

Testosterone is synthesized by Leydig cells. Sertoli cells aid in spermatogenesis. The seminal vesicles secrete semen, which comprises most of the seminal fluid. The scrotum is the skin pouch which contains the testes. The spermatic cord contains the vas deferens, nerves, blood vessels, and lymphatic vessels. Note that Leydig cells are sometimes called interstitial cells.

The menstrual phase is divided into two halves—the first 14 days are involved in follicular maturation, and is thus known as the follicular phase, while the last 14 days involve the degneration of the corpus luteum, and is thus known as the luteal phase. Ovulation occurs around day 14, but there is no ovulatory phase. Menstruation normally occurs during the first 2-7 days of the cycle, during the follicular phase.

The corpus luteum is what remains of the folliclle after ovulation. If the egg is fertilized, the corpus luteum will be maintained due to the HCG from the embryo. HCG mimics the action of LH, maintaining the corpus luteum, which keeps producing progesterone, which is necessary for maintenance of the endometrium of the uterus. LH and FSH are important in the menstrual cycle and estradiol an important hormone involved in female reproductive health and function. Most pregnancy tests detect HCG in the urine.

Sperm are produced in the testes. They then travel into the epididymis where they mature and are stored. During the time of ejaculation, the sperm are expelled into the right and left vasa deferentia which join and form the urethra, through which they leave the body.

The urinary bladder is not a part of the female reproductive tract. Rather, it collects urine created by the kidneys. The ovary produces the female gametes. The fallopian tubes transport the eggs from the ovary to the uterus each month. The uterus provides a location and the necessary nutrients to the fertilized egg that develops into the fetus. The vagina receives the penis during sexual intercourse and expels menstrual flow from the uterus.

Oxytocin is the hormone responsible for stimulating uterine contractions during pregnancy. All other answer choices occur via stimulation by estrogen.