Page 41 - Human anatomy COMPLETELY DONE1

If the egg is fertilized, that is, pregnancy occurs, progesterone will ensure the course of
pregnancy. If fertilization of the egg has not occurred, then approximately on the 14th
day after ovulation, the yellow body stops secreting the hormone. Under the changed
conditions, the uterine mucosa, which has grown under the action of progesterone, is
rejected. At the same time, rather large blood vessels burst, menstruation begins, which
lasts 3-5 days. After that, the uterine mucosa begins to recover.
Thus, the menstrual cycle includes the maturation of the follicle, ovulation,
formation and reverse development of the corpus luteum.

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