$2 DISSECTION OF THE VASCULAR SYSTEM. 



aortic intercostal or from tlie aorta at that level, pass 

 beneath the oesophagus to reach the root of the 

 lungs, and thence penetrate the lungs, following the 

 bronchi. 



3. The Cceliac Axis is a large branch given off from 

 the aorta as it pierces the diaphragm ; it passes for a 

 short distance into the abdominal cavity, and then di- 

 vides into three branches, as follows : 



a. The Hepatic Artery, the most anterior 

 branch, passes beneath the oesophagus at its junction 

 with the stomach, sends one or two large branches to 

 the liver, the true hepatic artery, one branch to the 

 duodenum, and finally is distributed to the pancreas. 



b. The Coronary Artery, the smallest of the 

 three branches, is distributed chiefly along the small 

 curvature of the stomach. 



c. The Splenic Artery, the most posterior divi- 

 sion, splits into two main branches distributed chiefly 

 to the spleen. Each sends branches to the stomach 

 along the great curvature, and some smaller branches 

 are given off to the pancreas also. 



4. The Superior Mesenteric Artery arises from the 

 aorta a short distance posterior to the coeliac axis. It 

 gives off a number of branches which supply the small 

 intestine and the greater portion of the large intes- 

 tine. Follow its course in the mesentery. 



5- Posterior to the last two small arteries are given 

 off, that on the left side being somewhat anterior to 

 the other. Each divides into two branches, one of 

 which passes anteriorly, the phre^iic arteiy, to supply 

 the diaphragm, while the other is distributed to the 

 muscles of the abdominal wall. This latter branch 

 supplies also the adrenal bodies. 



6. The Renal Arteries are two large trunks, one on 



