176 



ANATOMY OF TILE ABDOMEN, ETC 



vessels, and so outward over the large intestine of th< 

 opposite side, to the parietes of the abdomen and the 

 umbilicus. 



DUCTS, VESSELS, AND NERVES OF THE ABDOMINAL CAVITY. 



By raising the edge of the liver and drawing the intestines down- 

 ward, the biliary ducts, situated in the lesser omentum and lying 

 between the two peritoneal layers forming the pillar of the foramen 

 of Wiuslow, may be examined. 



From the duodenum a duct of variable size can be traced 

 backward toward the liver ; this is the ductus choledochus 

 communis ; it divides as it approaches the liver into two 

 branches, one of which comes from the neck of the gall- 

 bladder, and is called the cystic duct, the other, coming from 

 the transverse fissure of the liver, the hepatic duct; they 

 are accompanied by the hepatic artery and portal vein. 



The veins of the portal system may be found by pushing aside the 

 viscera and searching for them in the regions to which they belong ; 

 it is impossible to dissect them without making special preparation 

 for so doing. 



The PORTAL VEIN or SYSTEM is composed of those ves- 

 sels which return the blood from the chylopoietic viscera ; 

 they are the 



Inferior Mesenteric, 

 Superior Mesenteric, 



Splenic, 

 Gastric. 



The inferior mesenteric vein returns the blood from the rectum, 

 sigmoid flexure and ascending colon, terminating in the splenic vein. 



The superior mesenteric vein returns the blood distributed by the 

 superior mesenteric artery; it ascends in company with that vessel, 

 and behind the pancreas unites with the splenic vein. 



The splenic vein commences in the spleen by several branches, 

 which, uniting, form a large trunk which passes behind the pancreas, 

 receiving the gastric veins from the stomach and duodenum. The 

 union of this with the superior and inferior mesenteric veins forms 

 the portal vein. 



The portal vein lies in the lesser omentum, between the biliary ducts 

 and hepatic artery; it ascends to the transverse fissure of the liver, 

 where it divides into two branches, one for the right and the other for 

 the left lobe. 



The arteries of the various abdominal viscera all come from the 

 abdominal aorta ; the nerves from the pneumogastric and from the 

 sympathetic ganglia. Their dissection is one of considerable diffi- 

 culty, owing to the mobility of the viscera and the constant necessity 

 of changing their position, so as successfully to expose the different 

 trunks The aorta should first be found at the point where it per- 



