With the fifth fourteenth week of pregnancy the child, now called embryo, rapidly. Nazhinaet formed primitive nervous system with the brain and spinal cord. Developed yolk Vorsin also circulatory system, a bag chorionic heart starts beating a 25-day after conception. Although the embryo is no more than half a pea, is already head, begin to form eyes, ears and mouth. There are kidneys, liver, digestive tract and primitive umbilical cord. At the 26 th day there are the beginnings hands, two days later - the rudiments of legs.

Five weeks. Although the child's sex is determined at the time of conception, the differences in anatomy of male and female do not manifest until about the seventh week fetus. Between the rudiments of the legs has a gap with a piece of tissue, called genital tubercle. Inside the belly of the embryo there is a pair of embryonic gonads.During the seventh week of Y-chromosome (boys) stimulates these sex glands to the beginning of production of androgens - male sex hormones, which lead edge of the gap to grow together, forming the scrotum, and from the genital tubercle formed penis. Before birth the testicles pushed from the abdomen in the scrotum. In girls, the sex glands begin to produce female hormones, and gap becomes the external genitalia and the genital tubercle develops clitoris. Embryonic gonads turn into ovaries.

By the eighth week the fetus formation of the embryo is complete: there are eyes nose, ears and mouth with the lips, tongue, and the rudiments of teeth, hands with fingers knees, ankles, feet and toes. The new body is functioning: brains sends impulses that coordinate the functions of other organs, the heart knocking, stomach identifies gastric juice, the liver produces red blood cells, the hands move. The embryo grows by approximately one millimeter a day, every day, developing different parts of the body. Between 46 m and 48-th day the first real bone cells replace the cartilage in the skeleton. Appearance first bone cells in the hands of embryologists call the end of the period embryonic development. Since then, the growing child is called fruit.