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Menstrual Cycle

 Menstruation is the cyclic event of the release of the ovum from the ovary and
its removal from the body when fertilization does not happen. In humans, the
cycle repeats every 28 days.
Ovulation is when a mature egg is released from one of the ovaries.
What happens when the Egg is not fertilized?

 If ovulation takes place and a sperm cell doesn’t successfully fertilize the egg,
the egg will simply move down the fallopian tube, through the uterus, and
comes out through the vagina in the form of blood and mucous.

 During menstruation, the blood-rich endometrium of the uterus also breaks
down while the ovum is being removed from the body.

 Role of female sex hormones
 Estrogen, produced by the ovaries and later by the placenta, helps the uterus
to grow, maintains uterus lining ,steps up blood circulation and activates and
regulates the production of other key hormones.

 During ovulation, another hormone called progesterone is released from the
ovary. This hormone stimulates the uterus to maintain its thickening, as well
as glandular activity in uterus and vagina.

The complete development of foetus, from the initial stage of conception till
the birth of the young one, is called gestation. Gestation is completed in
about 280 days or 40 weeks from the first day of the last menstruation.
Parturition is the act of expelling the full-term young one from the mother’s
uterus at the end of gestation.

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