Where does menstrual bleeding occur?

We all know that women have menstruation, which happens to almost every woman. However, for some women who have just entered their menstrual period, they may not know some knowledge about women's physiology. Menstrual bleeding will make them feel scared and think they have a disease. In fact, this is a normal physiological development process of the uterus. So where does women bleed during menstruation?

After puberty, the reproductive organs mature and menstruation occurs. Menstruation is both cyclical and regular, like the waxing and waning of the moon, and like the ebb and flow of the tide. The normal physiological changes of the female-specific gonads - the ovaries - govern the cyclical changes of menstruation. So where does the menstruation we are talking about come from?

1Stage 1: Follicular development

At the beginning of each menstrual cycle, due to the stimulation of follicle-stimulating hormone and luteinizing hormone secreted by the hypothalamus-pituitary gland, the follicles in the ovaries grow rapidly, and one follicle matures. The mature follicle ruptures under the action of some enzymes and hormones and discharges the egg cell, which is the "ovulation" process of the ovaries.

At the same time, during the maturation of the follicles, more estrogen is produced, which can gradually thicken the endometrium and increase the number of glands, forming the proliferative endometrium. Estrogen reaches its peak 1 to 2 days before ovulation, inhibiting the hypothalamus and pituitary gland, reducing the secretion of follicle-stimulating hormone, while suddenly increasing the secretion of luteinizing hormone, causing ovulation.

3Stage 3: Conception or Not Conception

After the egg is released, the follicle turns into a corpus luteum, which secretes estrogen and progesterone. At this time, the endometrium thickens further, the blood vessels become richer, the glands grow larger, and have secretory functions, forming the secretory endometrium, which is fully prepared for the implantation of the fertilized egg.

If there is no sperm cell to meet with the mature egg cell waiting in the ampulla of the fallopian tube and conception fails, the corpus luteum will atrophy 10 days after ovulation, estrogen and progesterone will suddenly drop, the endometrium will lack the support of estrogen, the thickened endometrial blood vessels will become necrotic and fall off, followed by vaginal bleeding and menstruation.

5Stage 5: End of menstruation

The start of each menstrual period marks the end of the previous cycle. During a woman's reproductive period, menstruation repeats itself month after month.