THE POSTERIOR AORTA. 613 



The superior esophageal arter//, much more voluminous than the inferior, 

 inosculates with a branch of the gastric artery. In its course it gives descending 

 branches to the oesophagus, and ascending ones to the mediastinum. 



The inferior oesophageal artery also anastomoses with a branch of the gastric ; 

 most frequently with that noticed above. Ifc likewises furnishes ascending and 

 descending divisions ; the latter, however, going to the mediastinum, and the 

 former to the oesophagus. 



Innominate Ramuscules. — The innominate ramuscules of the broncho- 

 oesophageal trunk do not all proceed directly from it, there being always a 

 certain number which emerge from the bronchial or oesophageal arteries. They 

 are more particularly distributed to the trachea, to that portion of the oesophagus 

 which is in contact with the posterior extremity of that tube, to the bronchial 

 glands, the mediastinum, and the pulmonary pleura. Those destined for the 

 latter form on the surface of the lung — along with the divisions of the pleural 

 branch furnished by the gastric artery — a beautiful plexus. 



2. CcELiAC Artery (or Axis) (Fig. 365, 2). 

 This artery arises at a right angle from the inferior face of the aorta, 

 immediately on the entrance of that vessel into the abdominal cavity. After 

 a course from half to three-fourths of an inch at most, in the middle of the solar 

 plexus, and beneath the superior face of the pancreas, this trunk separates into 

 three branches — a middle, the gastric artery ,- a right, the hepatic artery ; and a 

 left, the splenic artery. 



1. Gastric Artery (the coronaria ventriculi of Man) (Fig. 365, 3). — This 

 artery descends on the large tuberosity of the stomach, extends to near the 

 insertion of the oesophagus, and then divides into two branches — the anterior 

 and posterior gastric. The first passes behind and to the right of the oesophagus, 

 and crossing the small curvature of the stomach, gains the anterior face of that 

 viscus, where it separates into flexuous and divergent branches that run beneath 

 the serous membrane, and are carried more particularly towards the left cul-de-sac 

 and around the cardia. The second vessel is distributed in the same manner to 

 the posterior wall of the organ, but chiefly to the right sac. 



Independently of these two arteries, the gastric trunk gives off a third and 

 constant branch, which often comes from one of its two branches, and sometimes 

 also from the coeliac axis itself, or from the splenic. This branch accompanies 

 the oesophagus, along with the right pneumogastric, crosses the opening of the 

 right pillar of the diaphragm to enter the pectoral cavity, and then divides into 

 two branches, each of which anastomoses with one of the oesophageal arteries, 

 and is then thrown over the posterior extremity of a pulmonary lobe, which it 

 covers with a magnificent subpleural reticular arborization. This gastro-pulmo- 

 nary artery often anastomoses with the superior oesophageal branch only, and 

 goes exclusively to the right lung ; for the left lung and the inferior oesophageal 

 artery, in this case there is a special branch that emanates from the anterior 

 gastric. It is not rare to meet with varieties of another kind, but of which 

 it is not necessary to speak ; inasmuch as in these pleural ramifications we find 

 a disposition common to the whole arterial system — distribution almost invari- 

 able, origin very inconstant. 



2. Splenic Artery (Fig. 365, 7). — The largest of the three branches of 

 the coeliac axis, this artery is directed downwards and to the left, lying beside 

 its satellite vein and the superior face of the left extremity of the pancreas. It 



