202 THE HUMAN BODY. 



(#A) with its convexity towards the head. From the heart 

 end of this arch arise the coronary arteries, which carry 

 blood into the walls of the heart. From the convexity of 

 the arch spring the three large trunks : the innominate 

 artery ; the left common carotid artery (cs) \ and the left 

 subclavian artery (ssi). The innominate soon divides into 

 the right subclavian (sd), and the right common carotid (cd) 

 Each common carotid runs up the neck on its own side, 

 and divides into branches for the neck, face, scalp, and brain. 

 Each subclavian continues across the arm-pit as the axil- 

 lary artery (AX), and then runs down to near the elbow as 

 the brachial artery (B). Just above the elbow it divides 

 into the radial and ulnar arteries (R, u,) which supply the 

 fore-arm, and end in small brandies for the hand 



Beyond its arch the aorta runs back close to the spinal 

 column as the thoracic aorta (A/), which gives off branches 

 to the walls of th chest and some organs in that cavity. 

 The vessel then passes through the diaphragm, and con- 

 tinues as the abdominal aorta (Aab) to the lower part of the 

 abdomen. The main branches of the abdominal aorta are: 

 (1) the cceliac axis, which divides into branches for the 

 stomach, liver, and spleen; (2) the -upper and lower mcsen- 

 teric arteries, which supply the intestines with blood; (3) 

 the renal arteries (K), which carry blood to the kidneys. 



What is meant by the aortic arch? Wh;it are its first branches? 

 What branches are given off from the upper side of the aortic 

 arch? Into what vessels does the innominate artery divide? To 

 what parts do the common carotid arteries carry blood? In what 

 does the subclavian artery terminate? What vessels supply the 

 fore-arm with blood? How do they end? 



What is the thoracic aorta? 



The abdominal aorta? Name the chief branches of the abdom- 

 inal aorta. What organs are supplied by the co3liac axis? The 

 mesenteric arteries? 'The renal arteries? 



