In the process of intercourse, the male gives millions of sperm, moving from the vagina to the uterus and then to the egg canal, and reaches only a few thousand cavities. The female produces one egg per month in the middle of the menstrual cycle, and the egg usually lives about 24 hours and if not fertilized, it dies.
If sperm coincide with the egg in the first trimester of the egg, they accumulate around the egg and begin to penetrate the layer of cells surrounding the egg. This is aided by the head of the sperm and the enzyme that is excreted from the head of the sperm.
The semen nucleus contains 23 chromosomes in the egg nucleus (23 chromosomes) in a process called fertilization, producing a fertilized egg containing 46 chromosomes half of it From the father, and half from the mother.
The period between fertilization and childbirth is called gestation, and it takes about nine months for the female to have a full embryo. This period can be divided into four basic stages:
The first stage:
From the fertilization stage until the end of the sixth week, the fertilized egg begins with a series of equal divisions within the egg channel. When the cells reach 16 cells called the tweet, they travel to the uterus into a hollow spherical mass consisting of hundreds of cells called the plastic capsule. The uterus is attached to the wall and is cultured inside it on days 6-9 of fertilization. The placenta, which is a tissue of fetal cells and endometrium, is then connected to the fetus by umbilical cord.
The head begins to form first, and then the peripheral buds are formed. The eyes are clearly visible while the facial features are not clear. It is amazing that the cardiac folds begin to pulse. In this period, the embryo surrounds a small amount of fluid called Protect the fetus from shocks and maintain its temperature stability.
The second phase:
And extends from the end of the sixth week to the twelfth week.
This phase is characterized by the appearance of features of the face and body of the fetus clearly, and the fingers are separate from each other, and the sex at the end of this stage, and grow muscles and nerves clearly.
third level:
From the end of the twelfth week to the twenty-second week, the fetus continues to grow at this stage and the bones begin to grow. The mother feels the movement of the fetus and completes the formation of the body’s internal organs. The embryo at this stage covers a thin waxy white layer that helps protect it inside the womb and usually disappears before birth.
Stage IV (fetal completed):
From the end of the 22nd week until the birth, the growth of all organs is completed at this stage, the fetus’s eyes are open, the nails appear clearly, the fetal position is gradually reversed and the head is downward towards the cervix normally in a position suitable for preparation for delivery.