Human Reproduction and Reproductive Health
What the exam tests
Human reproduction and reproductive health cover gametogenesis, the menstrual cycle, fertilization, pregnancy, contraception, sexually transmitted diseases, and assisted reproductive technologies. Questions often ask for the sequence of hormonal events or the correct site of a process.
Core rules
- Spermatogenesis produces four sperm from one primary spermatocyte; oogenesis produces one ovum and polar bodies. FSH and LH control gonadal function; testosterone supports spermatogenesis; estrogen and progesterone regulate the menstrual cycle.
- The menstrual cycle has follicular, ovulatory, and luteal phases. Ovulation is triggered by an LH surge. The corpus luteum secretes progesterone, which maintains the endometrium.
- Fertilization normally occurs in the ampulla of the fallopian tube. The zygote undergoes cleavage, forms a blastocyst, and implants in the endometrium. The placenta secretes hCG, progesterone, and estrogen.
- Contraception includes barrier methods, hormonal pills, IUDs, and surgical methods. ART includes IVF, ZIFT, GIFT, and ICSI.
Worked example
In a 28-day cycle, ovulation occurs around day 14. Sperm survive about 3–5 days in the female tract, and the oocyte is viable for about 24 hours. The fertile window is therefore approximately days 9–15, not just day 14. Reasoning: timing depends on gamete survival, so intercourse before ovulation can still lead to fertilization.
Traps
Do not place fertilization in the uterus; it occurs in the fallopian tube. Progesterone dominates the luteal phase; estrogen peaks just before ovulation. hCG maintains the corpus luteum early in pregnancy. In IVF, fertilization occurs in a laboratory dish, not in the fallopian tube.