Every future mother is interested in knowing how her baby develops, whom he looks like and what he can do at different terms of pregnancy. Currently, due to the existence of such a method of diagnosis as an ultrasound, a future mother can get to know her baby even before birth. The task of our article is to consider the development of the embryo for weeks and months.
Stages of development of the human embryo
It is worth saying that the intrauterine development of a person can be divided into 2 periods: embryonic and fruit. The embryonic period lasts from the moment of conception to the 8th week of pregnancy, when the embryo acquires human traits and all the organs and systems have been laid down. So, let's consider the basic stages of development of the human embryo. The starting point in the development of the human embryo for weeks is the fertilization of the egg with the sperm.
There are the following periods of embryonic development:
- The zygotic stage is short and lasts until the moment of division;
- stage of the blastocyst. At this stage, active multiplication of cells occurs, which results in the formation of a tube with a cavity inside;
- the stage of gastrulation is characterized by the transformation of an embryo from a single-layer into a two-layer embryo (ectoderm and endoderm);
- the stage of obosablivaniya characterized by the separation of organs and systems with their further development.
At 3 weeks of pregnancy, a protrusion is formed on the side of the back, which turns into a neural tube. The cranial thickening of the neural tube gives development to the brain, and the spinal cord is formed from the rest of the neural tube.
At the 4th week of pregnancy segmentation of the embryo takes place, tissue and organ formation begins.
Development of the embryo at the 5th week is characterized by the appearance of the rudiments of the handles.
In the development of embryo at 6 weeks, note the further formation of the handles and the beginning of the formation of the legs.
Development of the embryo at 7-8 weeks is characterized by the formation of fingers and the acquisition of human appearance.
At the described stages, multiple factors affecting the development of the embryo are noted. It is known that among smokers and women who consume alcohol, the embryo lags behind in development.
Stages of embryo and fetus development
After 8 weeks of pregnancy, the embryo is called a fetus and continues its further development, at this period the fetus has a weight of 3 grams and a length of 2.5 mm. At the 8th week of development, the baby's heart beats and the fetal heartbeat can be seen on ultrasound.
At the 9-10th week of development, the growth and development of the cardiovascular system, liver and bile ducts continues, and the urinary and pulmonary system is actively formed. At this stage of development, there are already genital organs, but they are not yet visible by ultrasound examination because of the small size of the fetus.
By the 16th week of pregnancy, the length of the fetus reaches 10 cm, the placenta and umbilical cord are already formed and the baby now gets everything needed through them. During this period, the fetus actively moves in the uterus, sucks the finger and swallows,
We examined the formation of the embryo for weeks, saw how the development of organs and systems, the development of elementary motor functions.