The first menstruation (menstruation) appears in girls around 12 -14. age. It is proof of the girl's sexual maturity and ovum production of egg cells.
Menstruation is a process in which an unfertilised egg cell is excreted with the expanded endometrium. From now on, gradually and also more and more regularly, the ovaries will produce approximately every 28 days, usually one ready to fertilize the cell. Such a cycle will be repeated until the age of menopause, that is until about 45.-50. age. The woman's reproductive period lasts for about thirty years. In the ovaries of the female newborn there are about 500,000 vesicles containing immature eggs. After the woman reaches puberty, more of them mature. The others gradually age, which may cause fetal damage in older mothers.
Ovarian egg formation is directed hormonally. Under the influence of the pituitary gland hormone (the superior endocrine gland, directing the work of all the others) in one, less often both ovaries, the maturation of one of the follicles begins. Its center is gradually filled with a liquid containing vesicular hormone - estradiol. At the same time, the egg cell matures inside. Estradiol causes the endometrium to loosen and regenerate after the previous menstrual period.
The process of maturation of the follicle with the egg takes about 14 days. A fully mature vesicle bursts, releasing an egg cell that is captured by the tube of the fallopian tube, while in the fallopian tube it is waiting for fertilization. The moment of the vesicle rupture and exhalation is called ovulation or ovulation. It can be sensed by a woman as not very severe pain in the abdomen or sacral region.
After the release of the egg cell, the follicle is transformed into the corpus luteum, which produces another female hormone, called progesterone. It prepares the endometrium to receive a fertilized egg, causing its strong blood supply. The prepared uterus will be able to nourish the developing embryo. In the event that within a dozen or so hours after ovulation fertilization does not occur, the corpus luteum gradually disappears. Thus, the level of progesterone in the blood is also reduced, which in turn causes the reduction of blood supply to the endometrium. After approximately 12-14 days from ovulation, it is removed along with the uninvolved egg. Exfoliation of the endometrium (menstruation) usually lasts 5-7 days.
If, however, the egg is fertilized, the corpus luteum does not disappear, but it transforms into so-called pregnancy body, still producing progesterone. It helps to maintain the developing pregnancy and during the course of it stops the maturation of subsequent eggs. For this reason, progesterone is often called a gestational hormone.
During the menstrual cycle, the woman's levels of female hormones change, which causes fluctuations in moods as well as changes in the appearance of the skin and hair. The least favorable period is the time just before menstruation, when the level of progesterone is the lowest. Hormonal changes also affect fluctuations in body temperature, which is used in one of the natural methods of determining fertility periods. However, it should be remembered that this method may be unreliable, especially in young girls.
The slogans were prepared on the basis of: Zbigniew Lew-Starowicz. Love and sex. Encyclopedic dictionary. Wroclaw 1999
