The Menstrual and The Menstrual and Ovarian CyclesOvarian Cycles

Vocabulary- The Vocabulary- The HormonesHormones

Secreted by Pituitary: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

Vocabulary- The Vocabulary- The HormonesHormones

Secreted by Ovaries:Secreted by Ovaries:

–Estrogen

Causes uterine lining to thicken

–Progesterone:

Works with estrogen to finish uterine lining thickening

Vocabulary- The CyclesVocabulary- 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

The Ovarian Cycle: YouTube video clip

Vocabulary- The CyclesVocabulary- 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

The Menstrual Cycle: The The Menstrual Cycle: The Video ClipVideo Clip

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

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 Phase

Days 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