| Term | Definition |
| Zygote formation | Occurs when nuclei of ovum and sperm unite (2n) - diploid after fertilization |
| Ovarian cycle | Events in the ovaries that occure during and after maturation of an oocyte |
| Menstrual cycle | Series of changes in the endomentrium of the uterus to prepare it to recieve the fertilized ovum |
| Reproductive cycle | Normally 28 days, divided int four phases |
| Menstrual phase | Days 1-5; caused by a dramatic drop in levels of estrogen and progesterone; primary follicles develop into secondary follicles; menstrual flow - 50-150mL (blood, mucus, and epithelial cells shed) |
| Preovulatory/proliferative phase | Days 6-13; one secondary follicle becomes dominant and secretes estrogen - helps repair endometrium - develops into graafian follicle; endomentrium gets repairs, grows thicker |
| Ovulatory phase | Day 14; caused by the release of FSH and LH; graafian follicle ruptures and releasesd secondary oocyte into fallopian tube; endometrium gets thicker |
| Postovulatory phase | Days 15-28; graafiun follicle collapes and becomes corpus luteum; E & P secreted by the corpus luteum cause continued growth of the endometrium |
| Corpus luteum | Formed during the postovulatory phase; secretes progesterone and estrogen which continue to thicken the endometrium and prepare it for fertilization; lasts 2 weeks if no fertilization occurs - turns into corpus albicans, which no longer secretes E & P |
| Human chorionic gonadotropin | Hormone secreted by the chorion (embryonic membrane) during fertilization; stimulates activity of the corpus luteum to continue producing estrogen and progesterone; is dectected in home pregnancy tests |