

advehent veins, is collected again by tl r>oure<1 into 



inferior vtna cava; a part passes directly to the vena cava through tl, 

 vciiosuso At this point the blood acquires some impurity from th 

 brought in by the vena cava itself and the portal vein. . imf 



blood then flows into the right atrium, is directed by the Eur 

 /through the foramen ovale into the left atrium, thence flows into the 



ie and is forced out into the aorta. % ~*A part of the blood flows on through 

 .aorta, a part is carried to the upper extremities and head and neek region 



Sup. vena cava- 

 Lungs 



Right ventricle 



Inf. vena oava 



Liver 



Ductus venr. 



Umbilical. vein - 

 Umbilical artery - 



Ant. part ot 



and 



Ductus arteriosus 



B Pulmonary artery 



|i Left ventricle 



vorta 



artery 



B Portal vein 





FIG. 244. Diagram illustrating the foetal circular 



Modified from I 



the relative imp ulood in different 



'.ading representing the most impure blood 



id arteries. The latter part, then beet- 

 ack to the right atrium by I h Inn and jugula" '^ i 



f cava; from the right atrium the greater portion ii 



and thence Is forced out. into tl. -mlmonary artery. Bui since t, 



ton-functional, this blood passi. 

 m in the aorta. The blood received by the m 

 us is but sligb 



joins the aortic stream di ; tal t< 

 This accounts for the ; 



