2. The egg cell released by ovulation on weekends was taken into the tube. The egg cell is directed towards the uterus by the hairs inside the tube in order to meet the sperm. On the other hand, millions of sperm cells in the seminal fluid released into the vaginal environment have started to race for the long marathon consisting of the vagina, cervix, uterine cavity and tubes. The egg cell attracts the sperm cells carrying the positive charge towards itself with the negative charge it is assumed to carry. Of the millions of sperm cells, those that are abnormally shaped, immobile and inadequate lose the race. The sperm's journey from the vagina to the egg is completed in approximately 10 hours, and only around 400 of them will have the chance to encounter the egg. Sperms that do not initially have the ability to fertilize gain the ability to fertilize during this journey. Sperm that encounter the egg cell make an effort to pass through the thick outer shell of the egg. The egg cell selects only one of the sperm. It takes 20 minutes for this lucky sperm to enter the egg. After the sperm cell enters the egg cell, the egg cell changes from negatively charged to positively charged and pushes the positively charged sperm cells away. After the sperm enters the egg cell, the sperm nucleus and the egg nucleus combine and fuse the split genetic material they carry. And a single-celled creature, which we call zygote, with 46 chromosomes (23 chromosomes come from the egg and 23 chromosomes come from the sperm) was formed. Pregnancy has now occurred.
Fertilization is the union of the egg and sperm and the fusion of chromosomes. It occurs at the widest part of the tubes near the tip. Fertilization is completed within 24 hours after ovulation.
The purpose of fertilization is; It is to complete the number of 46 chromosomes, half of which come from the egg and half from the sperm, to determine the gender and to stimulate the division of the first cell formed.
Sperm cells contain both X and Y, while egg cells contain only X chromosomes. If the sperm cell entering the egg cell carries an X chromosome, your baby will be a girl; if it carries a Y chromosome, it will be a boy (boy: 46, It replicates and makes a copy. Then the first division occurs and a two-cell embryo is formed. After the zygote reaches the two-cell stage, it divides repeatedly. The appearance of the cells, whose volume gradually decreases after each division, resembles a "berry" after 4 divisions. This embryo structure, called morula, is formed 3 days after fertilization.
As the cells multiply exponentially (2, 4, 8, 16 cells), the embryo moves towards the uterus with the cilia and contraction movements in the tubes. During this progression, the outer shell of the fertilized egg protects the embryo and prevents it from settling in the tubes before reaching the uterus. If this journey towards the uterus does not end in time, the embryo may settle in the tube and the type of pregnancy we call ectopic pregnancy may occur.
4 days after fertilization, the embryo reaches the uterus at the morula stage. When the embryo reaches the uterus, the secretions of the uterine glands pass through the outer shell and seep into this ball of cells. The cells gather to one side, forming a fluid-filled ring-shaped appearance (blastocyst). The cells collected on one side will differentiate into the baby, the cells collected in the ring on the outside will differentiate into the baby's partner (placenta) and membranes, and the fluid around the baby will form the baby's first fluid. After the embryo reaches the uterus, it circulates freely in the intrauterine fluid for 2 days. Then it attaches to the lining of the uterus (6 days after fertilization).
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