Formation of the primitive heart Source: p contractions of the primitive heart start between the twentieth and twentieth first day. Contact information is here: MacroGenics. These movements occur for peristlticas waves that if they initiate in the venoso seio and they force the blood through the tubular heart, this blood if form in the wall of the vitelino bag during the third week of intrauterine life, passes for the venoso seio of the heart through vitelinas veins and crion for the umbilicais veins. The blood of the primitive heart is distributed for the brachial arcs come of the aortic arcs. Later that they liberate the oxygen and nutrients for fabrics and agencies in development of the embryo and it receives the dioxide from carbon and its products of excreo the blood returns mainly to the heart for the cardinal veins. The blood that passes to primitive placenta (crion) liberates its products of excreo for the maternal blood and from it receives the oxygen and nutrients, this well oxigenado blood returns to the heart for the umbilicais veins.
The primitive heart only possesss a forecourt and one ventricle. The division to atrioventricular starts for return of the completed half of the fourth week being to the end of the fifth week, these processes had occurred of simultaneous form suggested then events as the division of the canal primitive ventricular forecourt, primitive ventricle that if divides in right and left ventricle in the end of the fourth week if it communicates with the right ventricle and aorta with the left ventricle. Division of the arterioso bulb and arterioso trunk In the fourth week, if form tumefaes in the wall of the arterioso bulb call of Christians bulbares that they are involved for mesnquimais cells. The arterioso bulb is incorporated gradually for the walls of the ventricles, and in the adult right ventricle it is represented by the arterioso cone that if he originates from the pulmonary trunk.