146 



HANDBOOK OF ANATOMY 



The Internal Mammary artery passes down on the pleura sup- 

 plying the adjacent parts the diaphragm and the upper part 

 of the anterior abdominal wall. 



Thfe Superior Intercostal artery passes backwards over the 

 pleura to the neck of the first rib. There it divides into two 

 branches for the supply of the upper two intercostal spaces. 



The Branches of the Thoracic Aorta are divided into two 

 groups visceral and parietal. The visceral branches supply the 

 bronchi, oesophagus, and pericardium, and several small branches 

 to structures in the vicinity. The parietal supply the inter- 

 costal muscles and the upper surface of the diaphragm. 



The Intercostal arteries, of which there are nine pairs, supply 

 the nine lower intercostal spaces. Each artery passes back- 

 wards behind the pleura and runs in the groove at the lower 

 border of each rib. The Subcostal pair of arteries are in series 

 with this, and run in the groove on the twelfth rib. 



The Branches of the Abdominal Aorta are in two groups 

 visceral and parietal. The visceral branches supply the abdom- 

 inal organs, the parietal branches supply the abdominal walls. 



The order in which the branches arise from the abdominal 

 aorta is as follows : 



1. Inferior phrenic. 



2. Cceliac axis. 



3. Middle suprarenal. 



4. Superior mesenteric. 



5. Eenal. 



6. Spermatic or ovarian. 



7. Inferior mesenteric. 



8. Middle sacral. 



9. Common iliac. 



