I 



THE SPLENIC ARTERY 595 



a little beyond the pyloric. It descends behind the superior portion of the 

 duodenum to the lower border of the pylorus, where it divides into the right 

 gastro-epiploic and the superior pancreatico-duodenal. It varies from 1.2 to 

 2.5 cm. (^ to 1 in.) in length. 



(a) The right gastro-epiploic artery [a. gastroepiploica dextra] passes from right to left 

 along the greater curvature of the stomach between the layers of the great omentum, and 

 anastomoses with the left gastro-epiploic branch of the splenic. From this anastomotic arch 

 are given off:— (i) Ascending or gastric branches, which supply the anterior and posterior 

 surfaces of the stomach, and anastomose with the descending gastric branches of the arteries 

 along the lesser curvature, (ii) Epiploic [rami epiploici] or omental branches — long slender 

 vessels which descend between the two anterior layers of the great omentum, and then, looping 

 upward, anastomose with similar slender branches given off from the middle and left colic, 

 and passing down in like manner between the two posterior layers of the great omentum. 



(6) The superior pancreatico-duodenal [a. pancreaticoduodenalis superior] — the smaller 

 division of the gastro-duodenal — arises from that vessel as it passes behind the first portion of 

 the duodenum, and courses downward behind the peritoneum, in the anterior groove between 

 the second portion of the duodenum and the pancreas, to anastomose with the inferior pan- 

 creatico-duodenal, a branch of the superior mesenteric. Both the inferior and superior pan- 

 creatico-duodenal give off duodenal [rami duodenales] and pancreatic branches [rami pancreatici] 

 to supply these organs. 



(3) The hepatic artery proper [a. hepatica propria] is the continuation of the 

 hepatic after the gastro-duodenal has arisen. It ascends between the layers of 

 the lesser omentum, preserving the relations of the main artery to the portal vein 

 and common bile (and hepatic) duct, and divides, near the porta hepatis, into 

 right and left branches. 



(a) The right branch [r. dexter], given off at the porta (portal fissure) of the liver, runs to the 

 right either behind the hepatic and cystic ducts, or between these strucures. At the right end 

 of the porta it divides into or more branches, which again subdivided as they enter the fiver sub- 

 stance for the supply of the right lobe. As it crosses the cystic duct ifc gives off the cystic artery. 



The cystic artery [a. cystica] courses forward and downward through the angle formed 

 by the union of the hepatic and cystic ducts, and just before it reaches the gall-bladder divides 

 into a superficial and deep branch. The former breaks up into a number of small vessels, which 

 ramify over the free surface of the gall-bladder beneath the peritoneal covering, and furnish 

 branches to the muscular and mucous coats. The deep branch ramifies between the gall- 

 bladder and the fiver-substance, supplying each, and anastomosing with the superficial branch. 



(6) The left branch [r. sinister], the smaller division of the hepatic artery, runs medialward 

 toward the left end of the porta hepatis, and, after giving off a distinct branch to the caudate 

 (SpigeUan) lobe, enters the left lobe of the fiver. 



3. The Splenic Artery 



The splenic artery [a. lienalis] — the largest branch of the coeliac artery — 

 arises from the left side of the termination of that vessel below the left gastric, 

 and passes along the upper border of the pancreas in a tortuous manner to the 

 spleen. It at first lies behind the ascending layer of the transverse meso-colon, 

 but on nearing the spleen enters the lieno-renal ligament, and there breaks up 

 into numerous branches, which enter the hilus and supply the organ. In this 

 course it crosses in front of the left medial crus of the diaphragm and the upper 

 end of the left kidney and is placed above the splenic vein. 



The branches of the splenic artery are: — (1) The pancreatic; (2) the left 

 gastro-epiploic; (3) the vasa brevia; and (4) the terminal. 



(1) The pancreatic branches (rami pancreatici) come off from the splenic at varying intervals 

 as that vessel courses along the upper margin of the pancreas. They enter and supply the 

 organ. One larger branch usually arises from the splenic about the junction of its middle 

 with its left third. Entering the pancreas obfiquely, it runs from left to right, commonly above, 

 and a fittle behind, the pancreatic duct, which it suppfies together with the substance of the 

 organ. 



(2) The left gastro-epiploic [a. gastroepiploica sinistra] arises from the splenic near the 

 greater curvature and below the fundus of the stomach, and, passing between the anterior 

 layers of the great omentum, descends along the greater curvature of the stomach from left 

 to right, and anastomoses with the right gastro-epiploic. Like that vessel, it gives off ascend- 

 ing or gastric branches to the anterior and posterior surfaces of the stomach respectively, and 

 long slender descending epiploic or omental branches to the great omentum which anastomose 

 with like branches from the right and left colic arteries. 



(3) The vasa brevia [aa. gastricse breves] come off from the splenic just before it divides into 

 its terminal branches, oftentimes from some of these terminal branches themselves. Passing 

 from between the folds of the lieno-renal ligament into those of the gastro-fienal, they thus 

 reach the fundus of the stomach, where, ramifying over both its anterior and posterior surfaces, 

 they anastomose with the left gastric and left gastro-epiploic arteries. 



