322 SPECIAL ANATOMY. 



571. B. Aorta descendens abdominalis, the abdominal aorta. 



Situation : almost in the middle, yet rather to the left, before the 

 first to the fourth abdominal [lumbar] vertebra ; surrounded in the 

 hiatus aorticus, close to duetus thoracicus and Ven. azygos by the 

 crura of the diaphragm ; in the cavity of the abdomen on the left 

 side of Ven. cava inferior, covered by gangl. ccdiacum, the corpus 

 pancreatis, and pars horizontal, infer, duodeni, the left em ul gent 

 vein, root of mesenterium, and lumbar portion of peritoneum (to 

 the left below). 



572. Anterior azygos branches (these are the arteries for the 

 organs of digestion). 



1. Coeliaca, the coeliac axis, half to one inch long, four lines diam. Origin : 

 at a right angle from the anterior wall of the Aorta, while still in hiatus aorti- 

 cus, close under artt. pkrenicce inferr. Position : behind the curvatura minor 

 of the stomach, on the right side of the Cardia, between the layers of the 

 small omentum, upon the superior border of the Pancreas, under the left 

 lateral part of the lobul. Spigelii, closely surrounded with plexus cceliacus. 

 Branches pass off from a single point (tripus Halleri), to Stomach, Liver, and 

 Spleen (all lying above mesocolon transvers.') 



1. Coronaria ventriculi sinistra, the smallest of the branches of the coeliaca. 

 Course : to the left and above to the right side of the cardia, then again 

 curves to the right, passes in the semicircle on the small curvature (be- 

 tween the layers of the small omentum), and anastomoses with art . cor. 

 vent, dextr. hepaticce. Branches : artt. cesophagece inferr. to the inferior 

 portion of the oesophagus; artt. cardiacce surround the cardia, and supply 

 \\iefundusventric.; artt. gast rices arise along the small curvature, and 

 supply the anterior and posterior walls of the stomach ; very frequently 

 a ram. hepaticus (to the left lobe of the liver). 



2. Hepatica. Course : transversely to the right, above the pancreas, to the 

 right before the trunk of the ven. portce, gives off art. pancreat icce. mediae, 

 and divides (one to two lines from origin) into a superior and inferior 

 branch. 



a. Ram. hepaticus, the superior branch, passes obliquely forwards to 

 the Porta, where it divides into art. hepat. dext. and sinistra. Posi- 

 tion : before foram. Winslowi in the lig. hepatico-duoden., below 

 the ven. portce, to the left side of duct, choledochus. 



1. Pylorica s. coronaria dextra, a small branch passes along the 

 small curvature to the left, supplies the anterior and posterior 

 surfaces of the stomach, and unites with coron. ventric. sinistra. 



2. Hepatica sinistra passes through the left portion of the Porta to 

 the left lobe of the liver, lobul. quad, and Spigelii. Branches 

 pass transversely. 



3. Hepatica dextra, thicker, passes, divided into several branches, 



