The Menstrual and The Menstrual and Ovarian CyclesOvarian Cycles

The Truth behind PMS!!The Truth behind PMS!!

What is going on all at What is going on all at once?once?

The Beginning and the End: The Beginning and the End: MenstruationMenstruation

Occurs if egg is not fertilizedDays 1- 5 Corpus luteum (yellow body) breaks down– This causes drop

in estrogen and progesterone

Uterine lining shedsFSH increases during

Phase 2: Follicular PhasePhase 2: Follicular PhaseDays 5 –13Low estrogen = FSH to be releasedThis stimulates growth of follicle– Egg begins to

matureFollicle matures causing estrogen levels up– Uterine lining

begins to thicken again

Phase 3: OvulationPhase 3: Ovulation

Days 13-15Sudden rush of FSHMajor SPIKE of LH– This causes

follicle to break and release egg into fallopian tube

FERTILIZATION MOST LIKELY TO OCCUR AT END OF OVULATION!

Phase 4: Luteal PhasePhase 4: Luteal Phase

Days 15-28LH and FSH levels crashCorpus luteum forms from broken follicleCorpus luteum secretes estrogen and progesterone– This thickens uterine

lining to prepare for egg