CH. XIX.] 



COURSE OF THE CIRCULATION 



215 



by the pulmonary artery, which divides into two, one for each lung, 

 then through the pulmonary capillaries, and through the pulmonary 

 veins (two from each lung) to the left auricle. From here it passes 

 into the left ventricle, which brings us back to where we started from. 

 The complete circulation is thus made up of two circuits, the one, 

 a shorter circuit from the right side of the heart to the lungs and 

 back again to the left side of the heart ; the other and longer circuit, 

 from the left side of the heart to all parts of the body and back 

 again to the right side. The circulations through the lungs and 

 through the system generally are respectively named the Pulmonary 



Pulmonary capillaries. 



Pulmonary artery. 



Superior cava or vein 

 from head and neck. 



Right auricle. 

 Inferior vena cava- 



Right ventricle. 



Portal circulation. 



Second renal circu 

 lation. 



Pulmonary veins. 

 Aorta. 



Arteries to head and 

 neck. 



Left auricle. 



Left ventricle. 



Gastric and intestinal 

 vessels. 



First renal circulation. 



...Systemic capillarit 



FIG. 105. Diagram of the circulation. 



and Systemic or lesser and greater circulations. It will be noticed 

 also in the same figure that a portion of the stream of blood having 

 been diverted once into the capillaries of the intestinal canal, and 

 some other abdominal organs, and gathered up again into a single 

 stream, is a second time divided in its passage through the liver, 

 before it finally reaches the heart and completes a revolution. This 

 subordinate stream through the liver is called the Portal circulation. 

 A somewhat similar accessory circulation is that through the kidneys, 

 called the Renal circulation. The difference of colours in fig. 195 

 indicates roughly the difference between arterial and venous blood, 



