THE HEART AND CIRCULATION. 109 



artery sends branches to the chest and shoulder and is 

 more frequently injured than any other artery except 

 the popliteal. Aneurism may occur in it and is very 

 likely to occur in the thoracic aorta. 



From the thoracic aorta branches go to various of the 

 chest contents, while the abdominal aorta supplies the 

 abdominal viscera. Among the branches of the abdomi- 

 nal aorta are: the celiac axis, which has a gastric, an 

 hepatic, and a splenic branch; the superior and inferior 

 mesenteric to the intestines; the renal; the suprarenal; 

 the spermatic or ovarian; the inferior phrenic; and the 

 lumbar. 



The common iliacs divide at the upper edge of the sa- 

 crum into the external and internal iliacs, of which the 

 latter with its branches supplies the walls and viscera of 

 the pelvis and the inner part of the thigh. The external 

 iliac and its branches go to the thigh, leg, and foot. 



Veins. Of the veins few need be mentioned by name. 

 The deep veins have the same names as the arteries they 

 accompany, though there are two innominate veins where 

 there is only one innominate artery, the subclavian and 

 internal jugular veins on either side joining to form an in- 

 nominate vein and the two innominates in turn forming 

 the superior vena cava. Of the superficial veins the 

 external and internal jugular correspond to the common 

 carotid arteries and return the blood from the head and 

 face. The external jugular vein is important because it 

 is the largest superficial vein in the neck and is often cut 

 in suicide. The median vein is found at the bend of the 

 elbow and is used in letting blood and in giving salt 

 solution, while the basilic is on the inner side and the 

 median cephalic on the outer side of the upper arm. 

 Varicosity often occurs in the internal or long saphenous 

 . and the external or short saphenous in the leg. The in- 

 ferior vena cava is formed by the juncture of the two 

 common iliac veins. 



Portal Circulation. The portal system of veins includes 

 four large trunks which collect the blood from the viscera 



