Lecture Notes: Menstrual Cycle & Fertility (Vocabulary Flashcards)

Vocabulary-style flashcards covering key terms and concepts from the menstrual cycle and fertility-related notes.

Episodic uterine bleeding in response to cyclic hormonal changes; includes menses and ongoing endometrial remodeling; average length ~28 days.

Menstrual Cycle

Phase of the cycle when the endometrium is shed; lasts about 4–6 days (range 2–7); blood loss ~30–80 mL; iron loss ~11 mg.

Menses

Onset of the first menstrual bleed; marks puberty and activation of the HPO axis; typically around 12.4 years (range 9–17).

Menarche

Hormonal system coordinating the menstrual cycle via GnRH, FSH, LH, estrogen, and progesterone.

HPO axis (Hypothalamus–Pituitary–Ovary axis)

Hormone from the hypothalamus that stimulates the pituitary to release FSH and LH; pulsatile release drives the cycle.

Gonadotropin-Releasing Hormone (GnRH)

Gonadotropin that promotes growth and maturation of ovarian follicles; active early in the cycle.

FSH (Follicle-Stimulating Hormone)

Gonadotropin that triggers ovulation and promotes formation of the corpus luteum; peaks mid‑cycle.

LH (Luteinizing Hormone)

Mature ovarian follicle containing the oocyte; visible on the ovary and ovulates the oocyte at ovulation.

Graafian Follicle

Release of the ovum from the ovary, triggered by an LH surge; typically about 14 days before the next period (cycle-length dependent).

Ovulation

Ruptured follicle remnant after ovulation; secretes progesterone (and some estrogen) to support potential early pregnancy.

Corpus Luteum

Fibrous scar replacing the corpus luteum if pregnancy does not occur.

Corpus Albicans

Uterine lining that thickens and then sheds; modified by estrogen and progesterone across proliferative, secretory, ischemic, and menstrual phases.

Endometrium

Estrogen-driven growth and thickening of the endometrium after menses; typically days 5–14.

Proliferative Phase

Post‑ovulation phase; progesterone causes endometrial glands to become corkscrew and glycogen/mucin to accumulate.

Secretory Phase

Late luteal phase around day 24–25 when hormones fall and the endometrium degenerates if fertilization has not occurred.

Ischemic Phase

Discharge during menses; includes blood, mucin, endometrial tissue, and unfertilized ovum; first day marks new cycle; total blood loss 30–80 mL.

Menstrual Flow

Slight pre‑ovulatory drop, then about a 1°F rise after ovulation due to progesterone; remains elevated until ~day 24.

Basal Body Temperature (BBT) Shift

Mid‑cycle ovulation pain/cramps; mild to moderate lower abdominal discomfort around ovulation.

Mittelschmerz

Cycle‑dependent mucus changes driven by ovarian hormones that regulate sperm passage; becomes fertile around ovulation.

Cervical Mucus

Thin, clear, watery mucus at ovulation that supports sperm survival and passage.

Fertile Mucus

Cervical mucus test where drying mucus forms fern-like patterns; positive indicates high estrogen and imminent ovulation; negative indicates progesterone dominance.

Fern Test (Arborization Test)

Test of mucus elasticity; positive indicates peak estrogen and high fertility; negative indicates progesterone dominance or low estrogen.

Spinnbarkeit Test

Male gamete produced by the testes; fertilizes the egg.

Sperm

Female gamete produced by the ovaries; fertilizable by sperm.

Ovum (Egg)

Union of sperm and egg to form a zygote (early pregnancy begins if the embryo implants).

Fertilization

Period around ovulation when conception is most likely; identified by fertile mucus and ovulation timing.

Fertility Window