VESSELS, NERVES, AND DUCTS OF THE LIVER. 867 



extremity and anterior surface of the stomach, on which it moves freely. 

 When the stomach is quite empty, the left part of this surface of the liver 

 may overlap the cardiac end of that viscus. To the right of the longitu- 

 dinal fissure the liver rests and moves freely upon the first part of the duo- 

 denum, and upon the hepatic flexure of the colon, at the junction of the 

 ascending and transverse portions of that intestine. Farther "back it is in 

 contact with the fore part of the right kidney and suprarenal capsule. 



Vessels. The two vessels by which the liver is supplied with blood are 

 the hepatic artery and the vena portse. The hepatic artery (p. 408), a 

 branch of the cceliac axis, is intermediate in size between the other two 

 branches of that trunk, being larger than the coronary artery of the 

 stomach, but not so large as the splenic artery. Its size is, therefore, small 

 in comparison with the organ to which it is distributed. It enters the 

 transverse fissure, and there divides into a right and a left branch, for the 

 two principal lobes of the liver. 



By far the greater part of the blood which passes through the liver, and 

 in this respect it differs from all other organs of the body, is conveyed to it 

 by a large vein, the vena portce (p. 479). This vein is formed by the union 

 of nearly all the veins of the chylopoietic viscera, viz., those from the 

 stomach and intestines, the pancreas and spleen, the ornentum and mesen- 

 tery, and also those from the gall-bladder. It enters the porta, or trans- 

 verse .fissure, where, like the hepatic artery, it divides into two principal 

 branches. 



The hepatic artery and portal vein, lying in company with the bile-duct, 

 ascend to the liver between the layers of the gastro-hepatic omentum, above 

 the foramen of Winslow, and thus reach the transverse fissure together. 

 The relative position of the three structures is as follows, The bile-duct ia 

 to the right, the hepatic artery to the left, and the large portal vein is behind 

 the other two. They are accompanied by numerous lymphatic vessels and 

 nerves. The branches of these three vessels accompany one another in their 

 course through the liver nearly to their termination ; and in this course are 

 surrounded for some distance by a common investment (Glisson's capsule), 

 which is prolonged into the interior of the organ. 



The hepatic veins, which convey the blood away from the liver, pursue 

 through its substance an entirely different course from the other vessels, and 

 pass out at its posterior border, where, at the bottom of the fossa already 

 described, they end by two or three principal branches, besides other smaller 

 ones, in the vena cava inferior. 



The lymphatics of the liver, large and numerous, form a deep and a 

 superficial set, already described (p. 493). 



Nerves. The nerves of the liver are derived partly from the coeliac plexus, 

 and partly from the pneumogastric nerves, especially from the left pneumo- 

 gastric. They enter the liver supported by the hepatic artery and its 

 branches ; along with which they may be traced a considerable way in the 

 portal canals, but their ultimate distribution is not known. 



EXCRETORY APPARATUS. The excretory apparatus of the liver consists of 

 the hepatic duct, the cystic duct, the gall-bladder, and the common bile- 

 duct. 



The hepatic duct, formed by the union of a right and left branch, which 

 issue from the bottom of the transverse fissure and unite at a very obtuse 

 angle, descends to the right, within the gastro-hepatic omentum, in front of 

 the vena portae, and having the hepatic artery to its left side. Its diameter 

 is about two lines, and its length nearly two inches. At its lower end it 



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