In the countries of the East, girls are forced to wear a burqa from the moment of their first menstruation. In Europe, such a need does not arise, but the appearance of monthly discharge in any case changes the girl physiologically. What is menstruation and why does it occur?
To answer this question completely, you must first talk about the structure of such an organ as the uterus. From within it is covered with a unique cover - the endometrium. Its peculiarity is that it is destroyed and restored almost completely every month, if pregnancy does not occur. Once a month, pieces of the endometrium go out with the blood. Therefore, there are characteristic clots in the discharge, it is not only one blood. Menstruation - this is the process of exit of the endometrium with blood from the vagina.
The process of destruction and restoration of the endometrium is under the control of female sex hormones. Only the endometrium is subject to cyclical fluctuations in hormones, which makes it also unlike other tissues.
What is menstruation from the point of view of a physiologist? Start over. After all, in order to be able to tear off the endometrium, it is necessary that it is formed. Endometrial cells grow and divide under the influence of estrogen. Such processes occur in the first half of the cycle, approximately in the first two weeks. If menstruation is not the first, then the rapid growth of the endometrium begins immediately after the previous menstruation. Under the influence of estrogen, the endometrium thickens, and also blood vessels grow through it. This is the preparation of the body for a possible pregnancy.
However, such rapid growth does not last long, in the second phase of the cycle begins the synthesis of the second hormone - progesterone. It has an inhibitory effect on the growth of the endometrium, which ceases to intensively develop. Instead, endometrial secretion of a particular medium is enhanced. This creates the conditions for a fertilized egg to easily penetrate the uterus. It is for this that the endometrium grows - so that the medium is suitable for implantation of an egg cell.
So how does menstruation happen? If pregnancy does not begin in this cycle, the level of estrogen and progesterone drops sharply at the end of it. But even one decrease in estrogen levels is enough to start menstruation. The day before the onset of menstruation, the arteries supplying the endometrium contract. The endometrial surface whitens and suffers greatly from a lack of blood. The next day, the arteries expand very sharply, and the blood breaks through the surface of the endometrium. The ends of the arteries die off after a while, but the small veins continue to bleed slowly. That is why a lot of blood is present in the menstrual flow.
What is menstruation from the point of view of a histologist - a tissue specialist? This is the death of the surface layer of the endometrium, which ends with its rejection. All that remains is a deeper, basal layer, on the basis of which the new endometrium will be “reborn”. This new endometrium will again form a special internal blood supply system, subject to female hormones. And again, the hormone level at the end of the cycle will drop, unless the egg is fertilized.
From this point of view, it is interesting why, when using oral contraceptives while skipping the exact time of taking the pills, red discharge begins, which can go into a full menstruation. The fact is that a decrease in the level of hormones in the blood instantly triggers a reduction in the arteries of the endometrium, and then their expansion.
In general, many doctors do not recommend oral contraceptives because the subtle mechanisms of regulation of hormone synthesis are disrupted, as a result of which unpleasant side effects begin. So this is not an easy way to prevent pregnancy. In addition, often conception still occurs, only a fertilized egg is not able to gain a foothold in the uterus, and therefore the pregnancy is terminated. In fact, this is an abortion, for which you will have to bear moral responsibility before your conscience in the first place. The body will not forgive this either.
What is menstruation? A regularly occurring process of endometrial rejection as a result of an unforeseen pregnancy.