The female ovary produces eggs every month and the uterus also prepares itself to receive the fertilized egg .
These preparations include:
- The uterus lining becomes thick and spongy.
- It becomes enriched with blood and tissue in order to nourish the embryo.
- However, if the egg is not fertilized, the lining is not needed anymore.
- The unfertilized egg too lives for just one day.
- After that, this lining slowly breaks and comes out of the vagina in the form of blood and mucus.
- It is a cyclic process which occurs every month and lasts for 2-8 days . This whole process is known as menstruation .
- The menstrual cycle begins once a girl hits puberty at the age of about 10-12 years.
- Menstruation stops temporarily when a girl gets pregnant.