Both males and females develop one pair of mesonephric ducts and one pair of paramesonephric ducts in the early embryonic stage. These two pairs of ducts develop into male and female reproductive ducts respectively, which are called primordial reproductive ducts. However, these two pairs of ducts are not permanent. When the gonads differentiate, these two pairs of ducts begin to evolve differently.
In males, the paramesonephric ducts degenerate, while the mesonephric ducts continue to develop into male reproductive organs;
In females, the mesonephric ducts and mesonephric tubules degenerate into remains, and The accessory mesonephric ducts continue to develop into the female internal reproductive organs.
The head of the female paramesonephric duct evolves into the fallopian tube; the middle section goes inward and downward, merges with the opposite side at the midline to form a tube, and evolves into the bottom and body of the uterus; its tail section evolves into into the cervix and upper vagina. The fusion of the paramesonephric ducts is incomplete in the early stage, and there is a septum between them, forming a bicornuate uterus; during development, this septum gradually disappears, and the uterine cavity becomes one, forming a single uterus. The above evolution is completed approximately before the embryo is 12 weeks old. At the end of the 12th week of the fetus, the uterine wall thickens, and the uterine body and uterine whiskers can be distinguished at this time; at the 16th week of the fetus, the myometrium and connective tissue begin to form; at the end of the 24th week, the epithelial layer of the uterine cavity has primitive gland buds; At term, the glands in the endometrium are relatively complete.
But the development of the uterus is perfect during the fertilization period.
This article is excerpted from \”The Clear \”Conception\” Plan\” provided by Baidu Reading Author: Sun Jianqiu and Xie Yingbiao