Chap. XII] 



SUMMARY 



231 



(Edema 



Foetal 

 Circulation 



Accumulation of lymph in tissues. 



1. Obstruction to flow of lymph from 

 tissue. 



May be caused 

 by 



Changes in 

 Vascular System < 

 at Birth 



1. 



2. 



2. Excessive transudation. 



Direct communication between right and left auricle 

 by means of foramen ovale. 



Direct communication between imibilical vein and 

 inferior vena cava. Ductus venosus. 



Direct communication between pulmonary artery 

 and aorta. Ductus arteriosus. 



Oxygen and nutritive substances obtained from 

 placenta. 



Umbilical vein and ductus venosus become obliter- 

 ated. 



2. Respiration stimulates pulmonary circulation ; this 



raises the blood pressure in left auricle, and 

 closes foramen ovale. 



3. Ductus arteriosus becomes a fibrous cord. 



4. Hypogastric arteries become obliterated. 



1. 



