Why do women have menstruation? Why do women have menstruation?

Many women are troubled by their menstruation because it causes a lot of inconvenience to women during menstruation. For example, they cannot eat cold or spicy food. At this time, women's bodies are very weak. Some women also have abnormal menstruation, which is very painful. So many women feel that it is unfair. Why do only women have menstruation and not men? So why do women have menstruation?

This starts with the girl's eggs.

All of a girl's follicles are produced during the fetal period. (6 million embryos, 3 million at birth)

As girls grow older, primordial follicles continue to die.

By puberty, only a small number of follicles survive, about 300,000.

Theoretically, only 400 to 500 follicles can mature and complete ovulation in a girl's lifetime.

But what does this have to do with my aunt?

When girls reach adulthood, they have a mysterious ovulation cycle in their bodies, called the menstrual cycle!

Including the follicular phase, ovulation phase, and luteal phase!

①Follicular phase

The follicular phase starts from the first day of a girl's menstruation (that is, the first day of blood discharge).

That is to say, the menstrual period is included in the follicular phase! At this time, there are 15-20 follicles growing in one ovary. But only one follicle will develop best, called the dominant follicle. Don't think that only the war between sperms is cruel, brutal and brutal, the same is true for eggs! For its own growth, the dominant follicle will inhibit other growing follicles in the ovary, which is an extremely bicth method.

②Ovulation period

Once it is released, other follicles stop growing and then die, and the girl's body enters the ovulation period. The egg is captured by the fallopian tube and escorted all the way to the uterine cavity, waiting for the visit of sperm. Sometimes girls will have a little vaginal bleeding during ovulation. This is normal. If there is heavy bleeding for a long time, you should see a doctor.

3. Luteal phase

Note that it is not the cucumber stage...After the egg is released, the empty follicle will evolve into a new tissue called the corpus luteum. The corpus luteum secretes progesterone, the main component of progesterone. Estrogen and progesterone, upon hearing that sperm is coming, continue to gather around and reach a peak in the girl's body.

④ Menstrual period

If the sperm fertilizes the egg, the fertilized egg will go down the fallopian tube into the uterus, and the girl will become pregnant.

If there is not a large wave of sperm rushing towards the egg. Under the command of the pituitary gland, estrogen and progesterone retreat in disappointment when they find that sperm has not come (alas, sperm did not come this time), and the secretion amount decreases.

The small arteries supplying the endometrium will become very unhappy, spasming and contracting like crazy, and then rupturing, causing the endometrium to become ischemic, necrotic, and shed, and this is when your period comes.

(My period is coming, run away... You can't escape~)

At the same time, 15-20 follicles are growing secretly in one of the girl's ovaries...

The fact that girls have their periods is a manifestation of human evolution and wisdom, as it prevents excessive growth of the endometrium and abnormal changes such as cancer. It is also a sign of failure in female conception. But she never gave up after the ovaries and uterus failed, and continued to reliably prepare for the arrival of sperm... I was deeply moved by this spirit, which is very worthy of our learning and admiration!