THE VISCERAL BRANCHES. 799 



{bb) Gastric branches which pass downward over both surfaces of the stomach, anasto- 

 mosing with the short gastric branches from the splenic artery and with the gastric branches 

 which pass upward from the gastro-epiploic arch which passes along the greater curvature of 

 the stomach. Some of the branches which arise from the more proximal portion of the artery 

 and ramify over the cardiac portion of the stomach are frequently described as the cardiac 

 branches. 



(cc) A small hepatic branch passes upward betvyeen the two layers of the lesser omentum 

 towards the left end of the transverse fissure of the liver, where it anastomoses with the left 

 branch of the hepatic artery. 



Variations. — The gastric arten,r occasionally arises directly from the abdominal aorta, in 

 which case it may give rise to one or both of the inferior plirenic arteries. Its hepatic branch is 

 not infrequently enlarged, and then constitutes the main stem of the left branch of the hepatic 

 artery, which thus seems to arise from the gastric 



(d) The Hepatic Artery. — In the first portion of its course the hepatic artery 

 (a. hepatica) (Figs. 720, 721) passes from left to right and shghtly forward, over the 

 right crus of the diaphragm, lying beneath the posterior wall of the lesser sac of perito- 

 neum. Where this passes over into the posterior layer of the lesser (gastro-hepatic) 

 omentum towards the right, the artery bends upward and ascends, in the free edge of 

 the lesser omentum, tovi'ards the transverse fissure of the liver, where it divides into 

 two terminal branches. 



Relations. — In the first portion of its course the hepatic artery rests below 

 upon the upper border of the head of the pancreas and is in contact above with the 

 lower surface of the Spigelian lobe of the liver, upon which it frequently makes a 

 distinct impression. It lies at first upon a plane posterior to the portal vein, but 

 later it crosses the left surface of the vein and comes to lie in front of it. In its 

 course upward in the free edge of the lesser omentum the artery lies anteriorly to the 

 portal vein and upon the left side of the common bile-duct. 



Branches. — As the hepatic artery passes between the two layers of the lesser omentum it 

 gives origin to two branches, the pyloric and the gastro-duodenal. f 



{aa) The pyloric branch (a gastrica dextra) is the smaller of the two. It descends to the 

 pyloric end of the stomach and then, bending to the left, runs along the lesser curvature of the 

 stomach, between the two layers of the lesser omentum, and terminates by anastomosing with 

 the gastric artery. It gives branches to either side of the pyloric extremity of the stomach and, 

 like the gastric artery, is frequently represented by two parallel vessels. 



{bb) The gastro-duodenal (a. gastroduodenalis), the larger branch, descends behind the 

 first portion of the duodenum and terminates at its lower border by dividing into two branches, 

 the superior pancreatico-duodenal and the right gastro-epiploic 



[aaa) The superior paticreatico-duodenal branch (a pancreaticoduodenalis superior) descends 

 to the head of the pancreas, upon the surface of which it anastomoses with branches of the 

 inferior pancreatico-duodenal branch of the superior mesenteric artery. It sends branches into 

 the substance of the gland and to the walls of the duodenum. 



{bbb) The right gastro-epiploic artery (a. gastroepiploica dextra) passes to the left along the 

 greater curvature of the stomach, between the folds of the greater omentum, and inosculates 

 with the left gastro-epiploic branch of the splenic artery. It sends branches upward upon both 

 surfaces of the stomach, which anastomose with branches from the gastric artery and from the 

 pyloric branch of the hepatic, and other branches pass downward into the greater omentum 

 (epiploon). 



{cc) The terminal branches are two in number and pass the one to the right and the other 

 to the left lobe of the liver The right branch ( ramus dexter) passes towards the right extremity 

 of the transverse fissure of the liver, its course lying either in front of the hepatic and cystic 

 ducts or between these two structures. At the extremity of the fissure it divides into a number 

 of branches which enter the substance of the right lobe of the liver. As it passes across the 

 hepatic duct it gives off a cystic branch ( a cystica ) which runs downward and forward along 

 the cystic duct to the gall-bladder, whose walls it supplies, also giving some small branches to 

 the liver. The left branch (ramus sinister) is directed towards the left end of the transverse 

 fissure, and. after giving off one or two branches which enter the substance of the Spigelian 

 lobe, terminates by dividing into a number of branches which enter the left lobe of the liver. 



Variations.— Variations of the hepatic artery are exceedingly frequent. The artery itself 

 may arise directly from the aorta instead of from the coeliac axis, or. by the enlargement of its 

 anastomoses and the diminution of the normal main stem, it may appear to be a branch of the 



