What we can observe with everything this process is that the cardiovascular system if form close to the end of the third week from the esplnico mesoderm of the cardiognica area. Cardiac pipes pairs if form and if they establish to compose an only cardiac pipe. The primitive myocardium does not delay to involve this pipe the heart initiates its beatings in 21 to 22 day. In the end of the third week already it has a functional cardiovascular system, when growing the cardiac pipe if fold for the right and soon acquires a external aspect of an adult heart. The critical Period of development of the heart if points out between 20 day to 50 after the fertilizao. Due to complexity of the division of the heart the anomalies are relatively common and in particular the anomalies of the ventricular septos. Some congenital malformations result of the abnormal transformation of the aortic arcs for the arterial standard of the adult. As the pulmes they are not functional agencies during the prenatal life and the fetal cardiovascular system is structurally projected of form that the blood oxigenado in the placenta of them deviates a good part.
The modifications that establish the circulatrio standard after-Christmas to the birth are not abrupt, but if they extend for first infancy. The occurrence of the normal changes in the circulatrio system in the occasion of the birth does not result of the clear oval forame and/or in one ducto arterial patent. Functionally active the circulatrio system and its structures According to JUNQUEIRA, in its book basic histologia, the vascular system also encloses the sanguineous system and lymphatic vascular system that can be understood in the following functional structures: the heart, agency that whose function is to pump the blood for the sanguine vases, ace arteries that understand of a series of eferentes vases that if become minors the measure whom if they ramify, and whose function is to take the blood with nutrients and oxygen for the fabrics, hair vases that constitute a complex net of fine tbulos that if anastosomam profusamente and through whose walls promote the interchange between the adjacent blood and fabrics, the veins that result in the convergence of the vases capillaries in a system of ample canals the measure that it approaches to the heart.