Embryonic development begins with the momentconception and continues until the appearance of man to the light. In general, intrauterine development consists of 2 phases: the first two months are embryonic, and the subsequent (3-9) are called fetal. Intrauterine development lasts about 280 days, or 9 months. Embryo in obstetric practice is called the embryo, which develops in the body for about two months, then the embryo is called the fetus.
Embryonic development: from conception to birth
The muscular membrane of the epithelium contracts, forcingmove the egg along the fallopian tube to meet the sperm, male sex cells. As a result, fertilization occurs. Only one spermatozoon can penetrate into the egg cell, after which a protective shell appears around it, which prevents other spermatozoa from entering the interior. Embryonic development begins with the moment of fusion of two nuclei, forming a certain set of chromosomes. After this, the earliest stages of embryo development begin, which consist in crushing the cells into many small ones.
The baby eats yolk stocks that arein the egg. After a while, the embryo enters the uterus and an attachment or implantation takes place. Already on the 7th day the baby is gradually introduced into the uterus. After this, the embryo begins to produce chorionic gonadotropin, a hormone, which is a signal for the mother about the pregnancy that has come (it provides the appearance of two strips on the test).
On the 10-14th day the embryo, whose developmentpasses at a normal pace, becomes more than 2 times. Further embryonic development occurs rapidly rapidly. The nervous system begins to form on the 20th day of pregnancy. Three weeks later, the baby's heart beats. At a period of about 28 days there is a spine, muscles. Using the ultrasound examination, the hands, feet, ears and eyes of the child are visible.
In just 30 days, the size of the baby increased by 10thousands of times, and continues to develop intensively. Five days later, fingers and toes are already visible, eyes darken, as the baby's body produces a special pigment.
At 6 weeks, the brain begins to controlwork of the heart and movement of the muscles of the embryo. The liver produces blood cells. A week later the child's eyelids appear, which protect the eyes from dryness and light. On this term of pregnancy the outer and inner ear of the baby is actively formed, the rudiments of the teeth are born and the jaws begin to form. However, the most important and significant change is that the little man starts moving in the womb. Unfortunately, it is still too small for Mom to feel these movements.
8 недель – важная веха в развитии младенца.At this stage of development, he already resembles a person. Its size is only 2, 5 centimeters, and his heart is already beating confidently, muscles contract, the face acquires certain features, and the body reacts to touch. After 2 weeks the child grows up to 4 centimeters and weighs about two grams. It is this period characterized by the formation of the genital organs of the baby.
At the 12th week he already sucks his finger and vigorouslytrains muscles. The kid begins to turn his head, bend his fingers on the handles, open and close his mouth. At this time the fruit sees and hears, closes the ears with hands in response to sharp sounds and turns away from the bright beam of light. In the period from 16 to 24 weeks there are active changes, which consist in the appearance of the hairline, cilia. The kid is already smiling, hiccups, and my mother feels it distinctly. From 24 weeks to 34th embryonic development is almost complete, the baby is already free to express emotions (joy, anger, discontent). He can see dreams. The photos show a pout or smile. 36-38 weeks are the final stage of the child's development. Now he is completely ready to be born.
