198 



THE HUMAN BODY. 



capillaries, as may readily be seen by tracing the course of 



the vessels in Fig. 57. 



The Vessels connected with the Different Chambers of 



the Heart. One big ar- 

 tery, called the aorta, 

 springs from the left 

 ventricle ; it runs back 

 to the pelvis after giving 

 off very many branches 

 on its way and then di- 

 vides into an artery for 

 each leg. Its big branches 

 divide into smaller and 

 these into smaller again, 

 until they become too 

 small to be traced by the 

 unaided eye. They spread 

 through the whole body, 

 to muscles, and bones, 

 and skin, and brain, anl 

 stomach, and intestines, 

 GREAT an( j ij ver ^ an( j kidneys ; 



V^eft k nev ^ na ^y enc ^ i n the sys- 



ventricle; 3, root of the pulmonary artery; 4, temiC Capillaries. The 



4 , arch of the aorta; 4 , the descending thoracic 



aorta; 5, part of the right auricle; 6, part of the svstpmiV vpino rrllA^f fko 



left auricle ; 7, 7', innominate veins joining to ^^ V61nS Collect "16 



form the vena cava superior; 8, inferior vena Vl /-/-/! -P^ 4-T, *n 



cava; 9, one of the large hepatic veins ; X, D10O(1 irom the Capllla- 



placed in the right auricnlo- ventricular groove, ., ,.. 



points to the right or posterior coronary artery; ries OI tne Ullierent Or- 



X, X, placed in the anterior interventricular 



groove, indicate the left or anterior coronary 2fanS. and all tnCSC Veins 



artery. 



What artery arises from the left ventricle ? To what point does 

 it run? What does it ive off on its course? How does it end? What 

 becomes of its branches? In what do they end? What vessels col- 

 lect the blood from the systemic capillaries? 



