Six common sense about the uterus that few women know

When men and women enjoy the pleasure of orgasm, do they notice the physiological reactions of women? In addition to the reactions visible to the naked eye, what reactions are there inside women's bodies, what reactions are there inside women's uteruses, and what secrets are hidden in women's uteruses?

1. Menstruation comes from the endometrium

The outer layer of the uterine wall is the endometrium, where menstruation occurs. After the menstrual period ends, under the action of estrogen secreted by the ovaries, endometrial cells begin to grow. From the 5th to the 9th day, a thin layer of endometrium covers the entire surface of the uterus, and then gradually thickens, and the number of uterine glands gradually increases.

On the 15th day, the ovary has ovulated and the endometrium continues to thicken under the stimulation of progesterone, reaching a thickness of 5 to 6 mm. On the 25th day, if the sperm is not fertilized, the levels of estrogen and progesterone will drop, the glands will shrink, and the endometrium will gradually become thinner. Eventually the endometrium loses its support and peels off, resulting in menstruation. In the womb, this drama happens once a month.

2. Why is the cervix an accident-prone area?

The cervix is ​​the connecting passage between the uterus and the vagina, and is also an area where accidents often occur. Female vagina is connected with the outside world and has more chances of being infected by bacteria in life, such as various microorganisms brought by vagina, invasion of bacteria after cervical damage due to miscarriage, or bacteria infected by unhealthy lifestyles.

However, these pathogens only reach the cervix and rarely invade the uterus. Because the cervical mucosa secretes mucus, a mucus plug is formed in the cervical canal, isolating the uterus from bacteria. Research has found that bacteria can be detected in the lower 1/3 of the cervical mucus plug, but there are no bacteria in the upper 2/3. In this way, the cervical opening becomes an important gateway to resist external bacteria, which means it will be stimulated by more pathogens.

3. The uterus provides energy to the fetus during pregnancy

During a woman's lifetime, the ovaries release about 400 to 500 ovulations, and ovulation usually occurs between the 13th and 16th days of the menstrual cycle, or around the 14th day before menstruation. If you have sex at this time, the chances of conception are relatively high. On the 15th day, the sperm and the egg meet and are fertilized in the fallopian tube. Soon the endometrium is notified and the original plan is stopped immediately. It continues to thicken at the existing 5mm thickness to be suitable for the implantation of the fertilized egg. It takes 3 to 4 days for the fertilized egg to pass through the fallopian tube and reach the uterus, choose a suitable implantation site and gradually approach it. Implantation is completed in 11 to 12 days, and the embryo and the mother become one.

4. How to find your ovulation day?

After a woman ovulates, a hormone called progesterone is produced in her body, which increases her body temperature to promote the implantation of the fertilized egg, so we can use changes in body temperature to find the ovulation day. The body temperature before ovulation remains at around 36.5℃, with a fluctuation range of 0.2℃. This is the low temperature period, also called the follicular period. On the morning of the day when the low temperature period ends, the body temperature will be 0.3~0.4℃ lower than the previous day. This day is the ovulation day. After ovulation, the body temperature quickly rises to about 0.3 to 0.5℃ and enters the high temperature period, also known as the luteal phase.

This high temperature will last for about 14 days. If you are not pregnant, the secretion of progesterone decreases, the endometrium sheds and becomes menstrual blood, the body temperature drops and the low temperature period begins again. This is the law of body temperature fluctuations. Basal body temperature is usually measured before getting up in the morning. It is recommended to use a special basal thermometer, which has a more precise scale and clear markings for different stages of body temperature. By correctly measuring your basal body temperature for a few months, you can accurately estimate your ovulation day.

5. Why does ectopic pregnancy occur?

After the semen is discharged, the adjacent end of the fallopian tube umbrella picks up the semen like picking up eggs, and then runs inside the fallopian tube toward the uterus with the help of the peristalsis of the tube wall and the activity of the cilia of the endometrium. If at this moment, the sperm also reaches the fallopian tube, fertilization can be completed, and the fertilized egg can implant, nurture and grow in the uterus. If inflammation or tumors (such as uterine fibroids) occur in the reproductive organs, affecting the peristalsis of the fallopian tubes, resulting in obstruction of the movement of the fertilized egg and implantation in the fallopian tube, an ectopic pregnancy will occur. 90% of ectopic pregnancies occur in the fallopian tubes.

6. Why is the fetus vulnerable to harm in early pregnancy?

The fetus depends on the placenta to survive in the mother's body. One side of the placenta is covered with villi, which contain countless tiny arteries and veins, tightly connected to the inner surface of the uterine wall. The small blood vessels converge into the main trunk and on the other side concentrate into the veins and arteries of the umbilical cord, connecting to the fetus. It replaces the functions of the fetus's lungs, liver, kidneys and gastrointestinal tract, bringing oxygen and nutrients from the mother and taking away carbon dioxide and metabolic waste.

In the placenta, maternal blood and fetal blood are separated by epithelial cells, which is the "placental barrier". It gives the placenta a defensive function and prevents pathogens such as bacteria from passing through the epithelial cells.

However, viruses and drugs can pass through, so this defense function is very limited. Especially in the early and middle stages of pregnancy, the placental barrier is weak and harmful substances will invade the placenta and cause abnormal fetal development. Therefore, there are four things to avoid in early pregnancy: avoid drug abuse, avoid contact with harmful substances, avoid infection, and avoid smoking and drinking, so as to prevent certain harmful substances from passing through the placental barrier and affecting fetal development.