The miracle of the emergence of a new life occurs in secret, hidden from prying eyes. 9 months, the baby develops in an organ called the uterus. It is adapted to protect, nourish, and at the end of pregnancy - to expel a child ready for independent life. The structure of the female uterus is ideal for all functions performed. It will be discussed further.
So, the uterus is a hollow organ, which means that there is space inside it. It is also a muscular organ, which allows it to adapt to the size of the baby, as well as participate in the birth process and shrink after childbirth so that the bleeding threatening the life of a young mother ceases.
The shape of the uterus resembles a slightly flattened inverted pear. Its upper part, connected with the tubes, is called, oddly enough, the bottom of the uterus. But the lower part, closer to the external opening, bears the name of the body of the uterus.
Inside, between the front and rear walls, there is a thin gap, the uterine cavity, in the upper corners of the gaps of the fallopian tubes begin . Below, the cavity turns into a channel of the cervix, the narrowest part of this organ. This channel opens into the vagina.
The structure of the woman’s uterus is very unusual. You can start with the fact that the mucous membrane here is different from everyone else in the human body. It is called the "endometrium." In a woman who is not pregnant, the endometrium is destroyed and rejected every 28 days into the uterine cavity. On average, this process (menstruation) lasts four days. Four days, the inner surface of the uterine cavity is an open bleeding wound. That is why doctors do not recommend having sexual relations during menstruation, although time is attractive for some men, and the risk of becoming pregnant in the first days of menstruation is zero. However, remember - an infection in an open wound these days is extremely likely. It is not for nothing that world religions prohibit sex in the days of “monthly purification”, this is a world experience, take care of yourself.
Blood from this exposed wound surface pours out along with the endometrium. Poets from medicine say that the uterus “cries” because pregnancy did not occur. After menstruation, the mucosa is restored. Both egg yield (ovulation) and menstruation depend on special cycles of hormone secretion by the body.
The structure of the woman’s uterus is very complex. The thickness of the uterine wall is about 1.2 cm. It consists of three layers - a thin external serous membrane, muscle layer and endometrium. There is no serous membrane on the lower surface in front. The muscle layer contains three bundles, two external bundles of muscles go obliquely and longitudinally, but in the middle - circularly. The largest vessels pass precisely in the middle muscle layer, therefore this layer was given the name of the vascular.
The endometrium has two layers: the functional, which is rejected and the basal, which after menstruation completely revives the destroyed functional. Basal remains during menstruation and almost does not change during the cycle.
The structure of the uterus during pregnancy has bright features. Smooth muscle cells of the muscle layer increase 10 times in length and 2-3 times in width. Cells divide, not just lengthen. This process is stimulated by estrogen.
The structure of the uterus of a woman, more precisely, the inner surface covering the uterus, depends on the phase of the cycle and the presence or absence of pregnancy. There are 3 states of the endometrium of a non-pregnant woman. Menstrual phase (first 4 days), reparative phase (lasts until the second day after ovulation), progestational phase (under the influence of progesterone, from ovulation to new menstruation). If fertilization occurs, a new organ is formed - the placenta.
Thus, the structure of the uterus of a woman changes in accordance with cyclic hormonal processes. And in pregnant women, changes are fundamental and affect even the muscle layer.