PY9.1-10 | Reproductive Physiology — Glossary

Sex-determining Region on the Y chromosome; the master switch that triggers testis differentiation from the indifferent gonad at ~7 weeks of embryonic life.

Hormone from Sertoli cells that causes regression of Mullerian ducts in male embryos; in adult females, AMH levels indicate ovarian reserve.

Neuropeptide that activates GnRH neurons in the hypothalamus; the key trigger for puberty onset and a regulator of reproductive function.

Hypothalamic peptide released in pulses that stimulates FSH and LH secretion from the anterior pituitary; pulsatile release is essential for normal function.

Anterior pituitary gonadotropin that stimulates follicle development in females and Sertoli cell function (spermatogenesis support) in males.

Anterior pituitary gonadotropin that triggers ovulation and corpus luteum formation in females, and stimulates Leydig cell testosterone production in males.

The process of sperm cell development in the seminiferous tubules, from spermatogonium through meiosis to mature spermatozoa; takes approximately 74 days.

Somatic cells within seminiferous tubules that support spermatogenesis, form the blood-testis barrier, secrete inhibin and AMH, and respond to FSH.

Interstitial cells of the testis that produce testosterone in response to LH stimulation.

Primary male sex hormone from Leydig cells; responsible for virilisation, secondary sexual characteristics, spermatogenesis, and anabolic effects.

Enzyme that converts testosterone to dihydrotestosterone (DHT), which is 10x more potent and responsible for prostate growth and male-pattern baldness.

Primary female sex hormone produced by granulosa cells; drives endometrial proliferation, secondary sexual characteristics, bone density, and at high levels triggers the LH surge.

Hormone from the corpus luteum and placenta; converts proliferative endometrium to secretory, maintains pregnancy, raises basal body temperature, and relaxes uterine muscle.

Temporary endocrine structure formed from the ruptured Graafian follicle after ovulation; produces progesterone and oestrogen; rescued by hCG if pregnancy occurs.

Sharp peak of LH secretion around Day 13-14 triggered by sustained high oestrogen (positive feedback); causes ovulation approximately 36 hours later.

Release of the secondary oocyte from the Graafian follicle, triggered by the LH surge; typically occurs on Day 14 of a 28-day cycle.

The ~28-day reproductive cycle comprising the ovarian cycle (follicular, ovulation, luteal phases) and uterine cycle (menstrual, proliferative, secretory phases).

Hormone secreted by the trophoblast that rescues the corpus luteum in early pregnancy; the basis of pregnancy tests; doubles every 48 hours normally.

The process by which the blastocyst embeds in the secretory endometrium (Days 6-10 post-fertilisation); the trophoblast invades and establishes the placenta.

Positive feedback loop during labour: cervical distension → oxytocin release → stronger uterine contractions → more distension → more oxytocin.

Anterior pituitary hormone that stimulates milk synthesis; tonically inhibited by dopamine; released in response to suckling.

Suppression of ovulation and menstruation during breastfeeding due to prolactin-mediated inhibition of GnRH pulsatility; provides natural contraception.

Permanent cessation of menstruation due to ovarian follicular depletion; defined as 12 consecutive months without menses; average age 51 years.

Common endocrine disorder characterised by anovulation, hyperandrogenism, and polycystic ovarian morphology; the most common cause of ovulatory infertility.

Assisted reproductive technique involving ovarian stimulation, oocyte retrieval, in vitro fertilisation, and embryo transfer; success rate ~30-40% per cycle.