1. The Menstrual and Ovarian Cycles

2. Vocabulary- The Hormones
Secreted by Pituitary:
FSH (Follicle Stimulating Hormone)
Stimulates follicle to cause egg to mature
LH (Luteinizing Hormone)
Causes release of mature ovum (ovulation)
Prepares uterus for implantation of fertilized egg

3. Vocabulary- The Hormones
Secreted by Ovaries:
Estrogen
Causes uterine lining to thicken
Progesterone:
Works with estrogen to finish uterine lining thickening

4. Vocabulary- The Cycles
Ovarian Cycle:
Occurs for 28 days in the ovaries
Process during which an ovum matures in a follicle and is released during ovulation
After ovulation, a corpus luteum (yellow body) is left behind

5. The Ovarian Cycle: YouTube video clip

6. Vocabulary- The Cycles
Menstrual (Uterine) Cycle:
Occurs for 28 days
Process during which uterine lining is preparing for fertilized ovum
If fertilization occurs, this cycle stops until after birth
If not fertilized, lining sheds (menstruation!) and cycle begins again

7. The Menstrual Cycle: The Video Clip

8. THESE TWO CYCLES ARE GOING AT THE SAME TIME!!!!!!!!!!!!!!!!!!!
I REPEAT: THESE CYCLES RUN TOGETHER AT THE SAME TIME!

9. What is going on all at once?

10. The Beginning and the End: Menstruation
Occurs if egg is not fertilized
Days 1- 5
Corpus luteum (yellow body) breaks down
This causes drop in estrogen and progesterone
Uterine lining sheds
FSH increases during

11. Phase 2: Follicular Phase
Days 5 –13
Low estrogen = FSH to be released
This stimulates growth of follicle
Egg begins to mature
Follicle matures causing estrogen levels up
Uterine lining begins to thicken again

12. Phase 3: Ovulation Days 13-15 Sudden rush of FSH Major SPIKE of LH
This causes follicle to break and release egg into fallopian tube
FERTILIZATION MOST LIKELY TO OCCUR AT END OF OVULATION!

13. Phase 4: Luteal Phase Days 15-28 LH and FSH levels crash
Corpus luteum forms from broken follicle
Corpus luteum secretes estrogen and progesterone
This thickens uterine lining to prepare for egg