CffiLIAC AXIS. HEPATIC ARTERV. 333 



The PHRENIC ARTERIES are given off from the anterior part of the 

 aorta as soon as that trunk has passed through the aortic opening. 

 Passing obliquely outwards upon the under surface of the diaphragm, 

 each artery divides into two branches, an internal branch which runs 

 forwards and inosculates with its fellow of the opposite side in front 

 of the oesophageal opening ; and an external branch which proceeds 

 outwards towards the great circumference of the muscle, and sends 

 branches to the supra-renal capsules. The phrenic arteries inosculate 

 with branches of the internal mammary, inferior intercostal, epigastric, 

 oesophageal, gastric, hepatic, and supra-renal arteries. They are not 

 unfrequently derived from the cceliac axis, or from one of its divisions, 

 and sometimes they give off the supra-renal arteries. 



The CCELIAC AXIS (zoiXia, ventriculus) is the first single trunk given 

 off from the abdominal aorta. It arises opposite the upper border of 

 the first lumbar vertebra, is about half an inch in length, and divides 

 into three large branches, gastric, hepatic, and splenic. 



Relations. The trunk of the cceliac axis has in relation with it, in 

 front the lesser omentum ; on the right side the right semilunar ganglion 

 and lobus Spigelii of the liver ; on the left side the left semilunar gan- 

 glion and cardiac portion of the stomach ; and belou\ the upper border 

 of the pancreas and lesser curve of the stomach. It is completely 

 surrounded by the solar plexus. 



The GASTRIC ARTERY (coronaria ventriculi), the smallest of the 

 three branches of the cceliac axis, ascends between the two layers of 

 the lesser omentum to the cardiac orifice of the stomach, then runs 

 along the lesser curvature to the pylorus, and inosculates with the 

 pyloric branch of the hepatic. It is distributed to the lower extremity 

 of the oesophagus and lesser curve of the stomach, and anastomoses 

 with the oesophageal arteries and vasa brevia of the splenic artery. 



The HEPATIC ARTERV curves forwards, and ascends along the 

 right border of the lesser omentum to the liver, where it di slides into 

 two branches (right and left), which enter the transverse fissure, and 

 are distributed along the portal canals to the right and left lobes.* It 

 is in relation in the right border of the lesser omentum, with the 

 ductus communis choledochus and portal vein, and is surrounded by 

 the hepatic plexus of nerves and numerous lymphatics. There are 

 sometimes two hepatic arteries, in which case one is derived from the 

 superior mesenteric artery. 



The Brandies of the hepatic artery are, the 



Pyloric, 



Gastro-duodenalis, \ gastro-epiploica dextra, 

 I Jrancreatico-Quoaenalis. 

 Cystic. 



* For the mode of distribution of the hepatic artery within the liver, see the 

 " Minute Anatomy " of that organ in the Chapter on the Viscera. 



