The lymphatic bed (LB) is being formed by means of the embryonic veins collaterals blocking from the blood flow: the arteries with the tunica externa are being intussuscepted into the extraorganic veins together with their endothelial walls, having separated the veins´ peripheral part into the lateral pockets. The veins widening in the intensively growing organs surrounding is being resulted in the veins central canals communications contraction and the interruption with their lateral pockets, in the separation from the lymphatic fissures veins with the endothelial lining. The fissures are being conjugated into the lymphatic sacci and the trunks. The two umbilical arteries without the multiple branches are being belonged to the umbilical vein with their endothelial walls. The embryo´s thick umbilical cord is slowly being grown in the length, and it is not being spiralized at all. The elastic Wharton´s jelly is being increased its resistance to the external pressure. The fetuses´ umbilical cord is being spiralized, but the umbilical vein walls are already being included, as the tunica externa, well as the tunica media. The placenta vascular bed without LB is presented itself the particular case of the cardiovascular system development, which, in its turn, is confirmed the vessels adequacy to the serviced organs structure and the corresponding functions. Having taken into consideration the LB laying mechanics, its morphogenesis would be able to be caused the blood supply disturbance and also the embryo death in the umbilical cord, and in the placenta. The placenta embryo drainage is being organized through the intervilliferous lacunas into the uterine vessels. So, they are usually being appeared, as a result of the endometrium vessels strong deformation and the following destruction in the process of the embryo implantation.
The paper has been presented for the «Fundamental researches» International Scientific Conference, Croatia, July 25 - August 1, 2009. Cameto the editorial office on 23.06.2009.
