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The Menstrual Cycle. A repeating series of changes in the lining of the uterus or ENDOMETRIUM in preparation of uterus receiving a fertilized egg is called the MENSTRUAL CYCLE. Menstrual Cycle.
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A repeating series of changes in the lining of the uterus or ENDOMETRIUM in preparation of uterus receiving a fertilized egg is called the MENSTRUAL CYCLE • Menstrual Cycle • the menstrual cycle begins at puberty & lasts 30-40 years until MENOPAUSE when hormones change & egg production stops • this cycle repeats “APPROXIMATELY” every 28 days
3 Phases of the Menstrual Cycle 1. Menses 2. Proliferative stage 3. Secretory Phase Menses Secretory Phase Proliferative Phase
MENSES • begins with the shedding of the lining of the uterus • tissue, cells, blood, etc., are passed from uterus to outside of body • this phase lasts an “AVERAGE” of 5 days
PROLIFERATIVE PHASE • as MENSES ends the uterus is repaired and prepared for receiving another egg • ovulation occurs around day 14 and the egg begins its journey to the uterus
the hormones FSH & LH play a large role in when and how this happens
SECRETORY PHASE • lasts from day 15 to 28 (APPROXIMATELY) • phase is named for the CORPUS LUTEUM which produces ESTROGEN & PROGESTERONE
if the egg is not fertilized (NO PREGNANCY) the hypothalamus signals to stop producing FSH & LH • as hormone levels drop the lining of the uterus begins to shed & the cycle starts again