To understand how a fetus grows and develops, we must first understand the process of fertilization. After the egg cell is discharged from the ovary, the fimbriae of the fallopian tube capture it into the fallopian tube. If sperm cells (sperm) enter the body at this time, they can pass through the cervix and uterus and enter the fallopian tube. They meet the egg in the ampulla of the fallopian tube and combine to form a new cell, which is called a fertilized egg or pregnant egg. This process is called fertilization.
The fertilized egg gradually moves toward the uterine cavity by the peristalsis of the fallopian tube muscles and the ciliary swing of the fallopian tube mucosal epithelium, and reaches the uterine cavity about 4 to 5 days after fertilization. At this time, the fertilized egg undergoes multiple divisions and changes to become a blastocyst. After another 3 to 4 days, the blastocyst combines with the endometrium and is buried in the endometrium, which is called implantation. Continuing development, the fetus and placenta are formed. The whole process takes 5 to 6 weeks. On the 20th to 30th day of the embryo, many disconnected gaps appear in the embryo, and then synthesize into a horseshoe-shaped cavity, that is, the body cavity. The mesoderm that forms the heart becomes the heart tube at the end of the third week and is connected to extraembryonic blood vessels. From the 9th week of pregnancy to full-term pregnancy, the fetus begins to take on a human shape and develops into various tissues and organs that can adapt to life after leaving the mother\’s body. During this process, the placenta continues to secrete hormones to maintain pregnancy, and a series of changes occur in the mother\’s body to allow the fetus to grow.
This article is provided by Baidu Reading and is excerpted from \”The Clear \”Conception\” Plan\” Author: Sun Jianqiu and Xie Yingbiao