292 



THE HUMAN BODY 



the upper and lower vence cavce, or "hollow" veins; so called by the 

 older anatomists because they are frequently found empty after 

 death. Into the back of the right auricle opens also another vein, 

 Vc, called the coronary vein or sinus, which brings back blood 

 that has circulated in the walls of the heart itself. Springing from 



ABi 



ori 



Vd 



FIQ. 103. The heart and the great blood-vessel attached to it, seen from the 

 side towards the sternum. The left cavities and the vessels connected with them 

 are colored red; the right black. Atd, right auricle; Adx and As, the right and 

 left auricular appendages; Vd, right ventricle; Vs, left ventricle; Aa, aorta; Ab, in- 

 nominate artery ; Cs, left common carotid artery ; Ssi, left subclavin artery ; P, main 

 trunk of the pulmonary artery, and Pd and Ps, its branches to the right and left 

 lungs; cs, superior vena cava; Ade and A si, the right and left innominate veins; 

 pd and ps, the right and left pulmonary veins ; crd and crs, the right and left coro- 

 nary arteries. 



the left ventricle, and appearing from beneath the pulmonary 

 artery when the heart is looked at from the ventral side, is a great 

 artery, the aorta, Aa. It forms an arch over the base of the heart 

 and then runs down behind it at the back of the chest. From the 

 convexity of the arch of the aorta several great branches are 

 given off, Ssi, Cs, Ab; but before that, close to the heart, the aorta 



