After a life-and-death competition, the sperm finally combines with the egg to produce a fertilized egg. Nextthe movement of the fertilized egg from the fallopian tube to the uterus depends entirely on the peristalsis of the female fallopian tube and the swing of the cilia!
The fertilized egg moves very slowly. In the first 24 hours, it remains motionless in place. On the second day, it enters the isthmus of the fallopian tube and stays in the isthmus for 2 days, where the cells divide and develop. Into morula.
The morula does not enter the uterus until the 4th day. At this time, the uterus has undergone miraculous changes, which is very different from 4 days ago when a large number of sperm passed through. The lining of the uterus becomes as soft as a carpet, and many little finger-like protrusions grow on it, allowing the fertilized egg that enters the uterus to attach to it. This scene is kind of like something, you know? Just like a rock climber using the protrusions on the rock wall to climb on the rock wall, the difference is that the rock climber is protected by a safety belt, but the fertilized egg has no protection at all, and this dangerous state will last for 2 full days. ! Therefore, many studies have reported that fertilized eggs easily fall from the uterine wall during this period.
On the 6th day after entering the uterus, the trophoblast of the fertilized egg secretes a protease that dissolves the endometrium and dissolves a 1 mm diameter gap in the endometrium. Once the fertilized egg is implanted into this gap , and escaped from an extremely dangerous state.
On the 12th day, this gap is repaired by the endometrium tissue, so the entire fertilization and implantation process is completed, and the fertilized egg returning to the uterus begins a new journey!
This article is provided by Baidu Reading and is excerpted from \”Pregnancy Can Be Simple\” Author: Feifei Mom