Embryonic development

Embryonic development begins from the moment of conception and continues until the appearance of a person 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. The embryo in obstetrical practice is called the embryo, which develops in the body for about two months, then the embryo is called the fetus.

Embryonic Development: from Fertilization to Birth

The muscular membrane of the epithelium contracts, forcing the egg to move along the fallopian tube towards the sperm, the male reproductive cells. As a result, fertilization occurs. Only one sperm can penetrate into the egg cell, after which a protective shell appears around it, preventing the ingress of other spermatozoa. Embryonic development begins with the moment of fusion of two nuclei, forming a certain set of chromosomes. After this, the earliest stages of the development of the embryo begin, which consist in crushing the cells into many small ones.

The baby eats yolk stocks that are in the egg. After a while, the embryo enters the uterus and an attachment or implantation takes place. Already on the 7th day the baby gradually penetrates into the uterus. After this, the embryo begins to produce chorionic gonadotropin, a hormone that signals to 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, which develops at normal rates, becomes twice as large. 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. With the help of ultrasound examination, the hands, feet, ears and eyes of the child are visible.

In just 30 days the size of the baby has increased by 10 thousand times, and continues to develop intensively. Five days after this, the fingers on the arms and legs are already distinguishable, the eyes darken, as the baby's body produces a special pigment.

At 6 weeks, the brain begins to monitor the heart and the movement of the muscles of the embryo. The liver produces blood cells. Another week later the child's eyelids appear, which protect the eyes from dryness and light. During this period 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 perturbations.

8 weeks is an important milestone in the development of the baby. 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 sucking a finger and vigorously coaching 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 hair, cilia. The kid is already smiling, hiccups, and my mother feels it distinctly. From 24 weeks until the 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.