326 



THE HUMAN BODY 



The Heart as seen from its Exterior. When the heart is viewed 

 from the side turned towards the sternum (Fig. 102) the two 

 auricles, Aid and As, are seen to be separated by a deep groove 

 from the ventricles, Vd and Vs. A more shallow furrow runs 

 between the ventricles and indicates the position of the internal 



vd 



FIG. 102. 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 subclavian 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 Asi, 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. 



longitudinal septum. On the dorsal aspect of the heart (Fig. 103) 

 similar furrows may be noted, and on one or other of the two fig- 

 ures the great vessels opening into the cavities of the heart may be 

 seen. The pulmonary artery, P, arises from the right ventricle, 

 and very soon divides into the right and left pulmonary arteries, 

 Pd and Ps, which break up into smaller branches and enter the 



