1. Menstrual Cycle

2. Understand the functions of:
Endometrium
Follicle vs. Corpus Luteum

3. Endometrium Inner lining of uterus Blood vessels
Preparation for implantation of zygote
Eventually forms placenta

4. Follicle vs. corpus luteum
Follicle = pre ovulation (egg present)
Protection/nourishment for egg
Secretes estrogen
Corpus luteum = post ovulation (no egg present)
Temporary endocrine gland
Secretes progesterone

5. Follicle vs. corpus luteum
Primary oocyte  secondary oocyte  ovulated
When does egg complete meiosis II?
Follicle  corpus luteum  degenerates (if no baby)

6. Menstrual Cycle

7. Roles of Specific Hormones
Luteinizing Hormone
Preovulation: __________________
Ovulation/Postovulation: ___________________
Follicle Stimulating Hormone
Postovulation: ___________________
Progesterone and estrogen are released by the _________________________ following ovulation
Estrogen
Leads to a spike in _______________, that causes ________________ at Day 14
Progesterone
Leads to thickening of the ___________________

8. Role of Specific Hormones
Luteinizing Hormone
Preovulation: follicular growth; signals meiosis I to continue occurring
Ovulation/Postovulation: follicle bursting (ovulation)… formation of corpus luteum
Follicle Stimulating Hormone
Preovulation: follicular growth
Postovulation: none (except preventing other follicles from developing)
Progesterone and estrogen are released by the corpus luteum following ovulation
Estrogen
Leads to a spike in LH, that causes _ovulation at Day 14
Progesterone
Leads to thickening of the endometrium

9. Confusing Ideas– Estrogen Levels
At very low levels, estrogen  increases GnRH  increase FSH and LH
Day 1
At low-ish levels, estrogen inhibits FSH and LH
Day 2-13ish
At high levels, estrogen stimulates LH and FSH (LH surge of ovulation)

10. Thought Question
Why is it important that low-ish levels of estrogen inhibit FSH and LH?
HINT: Think about what the roles of FSH and LH are

11. ANSWER
Prevents multiple follicles at multiple stages of development from constantly being produced– otherwise would constantly be concurring ovulating, menstruating, and in follicular and luteal phases with different follicles
Dramatic effect on hormones

12. Confusing Ideas– Estrogen and Progesterone Secretion
Estrogen produced by the follicle
Progesterone produced by corpus luteum

14. Hormone Changes After Pregnancy

15. Pregnancy vs. no pregnancy
If no sperm, leads to menstruation
If sperm, meiosis II completed in oviduct

16. Hormone Changes After Pregnancy
Corpus luteum  progesterone and estrogen
progesterone inhibit LH and FSH
Why is inhibition of FSH important?
Therefore, human chorionic gonadotrophin (HCG) mimics LH
Increased progesterone and estrogen which maintain endometrium

17. Blood and Urine Tests to Detect Pregnancy
Guideline to hCG levels during pregnancy:
hCG levels in weeks from LMP (gestational age)* :
3 weeks LMP: mIU/ml
4 weeks LMP: mIU/ml
5 weeks LMP: ,340 mIU/ml
6 weeks LMP: 1, ,500 mIU/ml
7 - 8 weeks LMP: 7, ,000 mIU/ml
weeks LMP: 25, ,000 mIU/ml
weeks LMP: 13, ,000 mIU/ml
weeks LMP: 4, ,400 mIU/ml
weeks LMP: 3, ,000 mIU/ml
Non-pregnant females: <5.0 mIU/ml

18. What Must Cause Estrogen and Progesterone Levels to Increase, even with decrease in hCG