As the first house of the fetus, the uterus pays for the growth of the fetus. You got it?

Sperm-egg combination is where sperm and eggs meet. Just like lovers 1 tryst, they usually don't stay at home, but may be outside the hotel restaurant. But if they are ready to get married, they will go home, and the fertilized sperm and egg will become a combination of sperm and egg after fusion. From two to four, and from four to eight, the combination of sperm and eggs is slowly accompanied by the shaking of microvilli of bilateral fallopian tubes and intestinal peristalsis of bilateral fallopian tubes. When you roll into the uterus, you will find a place where the embryo will be implanted, and now it will become his home, so the uterus is sperm and the uterus is the first residence of human beings. When the baby builds a house in the womb, that is, the embryo grows and develops in it, moves in it, eats in it, drinks in it, pulls in it and laughs in it. These are some thematic activities of the fetus in the womb.

What has the uterus experienced during the whole active service?

1, the endometrium gradually thickens on the day of ovulation: the endometrium is divided into dermis and functional layer, and the functional layer is affected by the estrogen production of uterus and ovary on the day of ovulation. The endometrium will thicken when it is in the same room on the day of ovulation, preparing for the implantation of embryos combined with sperm and eggs. However, if on the day of ovulation, a lucky sperm and egg will merge into a thick endometrium after sperm and egg combine, which will become the home where sperm and egg combine, and the embryo will implant, take root and grow in the endometrium, which will provide him with nutrition.

2, the uterus from small to large: as the baby continues to expand, the uterus will continue to expand. What everyone sees is that the stomach is getting bigger outside, not as big as the baby. Because it is still in the amniotic fluid and embryo of pregnant women, some people will see a lot of abdomen, but the baby is not big, but the uterus will definitely be pushed up. For a pregnant uterus, the uterine body expands to a volume of about 7×4×2 cm. In the third trimester, the uterus is 35×25×22 cm, and the fist size becomes like a melon weighing 20 kg. The volume of uterus in the third trimester is 5mL, which is 1000 times more than that in the third trimester, reaching 5000mL or even higher. The net weight of uterus should be 70g when not pregnant, and it will increase to 1 100g in the third trimester, which is 20 times stronger. When the uterus expands, the myocardial cells of the uterus are usually hypertrophy, and the somatic cells are filled with actin and myosin, which has elastic contraction performance. The key is to provide material conditions for uterine contraction before and after labor. The thickness of uterine muscle wall is 1 cm in the first trimester, and it becomes thicker to 2.0~2.5cm in the second trimester, and then softens to 1.0~ 1.5cm in the third trimester.

3, irregular contractions into regular contractions: the uterus should start to have some irregular contractions after the second and third trimester of pregnancy 13 weeks, but this contraction may not be very painful, generally chaotic and different. The key is to prepare for prenatal examination. In fact, what Ma Bao felt was bouts of abdominal stiffness.

4, changes in the uterus: in the early pregnancy, the mucosa will hematoma or even hypertrophy and looseness, and the glands in the cervix will increase, which has the effect of maintaining the uterine cavity from external erosion. Before labor, the cervix will be shortened and slightly dilated. Before delivery, it will gradually fade because of the opening of the cervical opening.