200 



THE HUMAN BODY. 



(Fig. 58), which are the two very first branches of the 

 aorta, and the blood from them is collected by the coronary 

 veins and poured by them directly into the right auricle. 



Sp 



Mpl 



Mpm 



PIG. 59. The left ventricle and the commencement of the aorta laid open, Mpm, 

 MpL the papillary muscles. From their -upper ends are seen the chordte tendinese 

 proceeding to the edges of the flaps of the mitral valve. The opening into the 

 auricle lies between these flaps. At the beginning of the aorta are seen its three 

 pouch-like semilunar valves. 



What are the coronary arteries ? The coronary veins ? 



