THE VASCULAR SYSTEM. 



margins of the translucent membranous valves to the 

 columnar carnese or muscular projections on the walls of 

 the ventricles. The walls of the auricles are thin in com- 

 parison with the walls of the left ventricle, which are twice 

 as thick as the walls of the right ventricle (Fig. 70). 



The auricles are very small when not injected, and may 



rs 



fie 



FIG. 70. VENTRAL ASPECT OF THE 

 HEART WITH ITS CAUDAL THIRD 

 CUT OFF TRANSVERSELY. 



a, Adipose tissue; be, innominate 

 artery; la, left auricle; }v, left 

 ventricle ; Ic, left carotid artery ; 

 o, ductus arteriosus ; pv, pul- 

 monary vein ; ba, pulmonary 

 artery; pc, superior vena cava; 

 psc, inferior vena cava; ra, 

 right auricle; re, right carotid 

 artery; rs, right subclavian 

 artery ; rv, right ventricle ; sb, 

 left subclavian artery; tr, tra- 

 chea. 



FIG. 71. DORSAL ASPECT OF THE 

 HEART OF THE CAT. 



ao, Aorta; ap, apex; as, azygos 

 vein; be, innominate artery; 

 ca, coronary artery ; cv, coro- 

 nary vein; /_, -left auricle; Ic, 

 left carotid artery ; Isb, left sub- 

 clavian artery; p, inferior vena 

 cava; pc, superior vena caya; 

 pa, pulmonary artery dividing 

 into its right and left branches ; 

 ra, right auricle; re, right ca- 

 rotid ; rs, right subclavian ; v, 

 pulmonary veins. 



by the beginner be cut away with the pericardium and sur- 

 rounding adipose tissue. The right auricle receives three 

 veins, the superior vena cava, inferior vena cava and coro- 

 nary veins, all of which enter its dorsal aspect. The portion 



