70 ARTERIES AND VEINS. 



Farther back a large branch is given off to the small intes- 

 tines. Follow it as it branches through the Mesentery. This 

 is the Anterior Mesenteric Artery. Find the branches of the 

 aorta that lead to the kidneys, the Renal Arteries. Some other 

 branches may be seen j and finally the aorta divides into two 

 large branches, the Common Iliacs supplying the two hind-limbs. 



4. Turn the stomach and intestines to the left, and observe 

 the two veins running forward from the two hind-limbs. These 

 are the two External Iliac Veins. By their union they form the 

 Postcaval Vein (formerly called the Vena Cava Inferior). 



5. Observe the veins from the kidneys, the Renal Veins. 



6. Trace the postcaval vein to the liver. Observe the vein 

 that gathers the blood from the intestine, the Mesenteric Vein. 

 This vein is joined by a vein from the stomach, the Gastric 

 Vein, one from the spleen, the Splenic, and one from the pan- 

 creas, the Pancreatic; together these form the Portal Vein, 

 which empties into the liver. Unlike other veins, the portal 

 vein subdivides, distributing the blood through the liver. The 

 blood thus distributed through the liver is recollected, and by 

 the Hepatic Veins joins the postcaval vein, close to the dia- 

 phragm, and almost wholly concealed by the liver. 



7. The postcaval vein passes by the liver, through the 

 diaphragm, and on to the right auricle. 



8. On removing the skin of the neck, there should be 

 found on each side the large Jugular Vein. Each of these is 

 formed by the union of the Internal and External Jugular 

 veins. 



9. Just before each jugular vein enters the chest cavity it 

 is joined by a vein coming from the corresponding fore-limb, 

 the Right and Left Subclavian Veins. The union on each side 

 forms the Innominate Vein. The two innominate veins unit- 

 ing make the Precaval Vein, which enters the right auricle. 

 In the rabbit there are two precaval veins. 



