1190 THE DIGESTIVE SYSTEM. 



The division between the superior surface and the posterior surface is not 

 marked by a border of any prominence, but by an indefinite margin which runs 

 transversely from side to side. 



The superior surface may be further divided into three areas, a superior, an 

 anterior, and a right, following the general direction of these portions of the 

 surface, but they are not clearly marked off from one another by borders. 



Their arrangement is as follows : 



The superior area of the superior surface lies in contact with the roof of the abdomen ; it is 

 convex on each side, and depressed near the median plane. The two convexities, of which the 

 right is the more prominent, fit into the two cupolae of the diaphragm ; whilst the central 

 depression, depressio cardiaca; corresponds to the position of the heart. The superior area (with the 

 exception of a small triangle at its posterior part, between the separating layers of the ligamentum 

 falciform e) is completely covered by peritoneum, and on it the division of the liver into right 

 and left lobes is indicated by the attachment of the ligamentuni falciforme. 



The anterior area of the superior surface is triangular in shape, and after death is usually 

 flattened, owing to the falling in of the anterior abdominal wall. In part it lies in contact with 

 the diaphragm, which separates it from the rib-cartilages on each side, but at the subcostal 

 triangle it comes into direct relation with the anterior wall of the abdomen, for a distance 

 usually of two or three inches below the xiphi-sternal articulation. It has a complete peritoneal 

 covering, and gives attachment, as far down as the umbilical notch at the inferior border, to the 

 ligamentuni falciforme, which connects it to the anterior abdominal wall. 



The anterior passes gradually into the upper and right areas, but it is distinctly separated 

 from the visceral surface by the sharp margo anterior of the organ. The umbilical notch is 

 often continued upwards for some distance on the surface as a slit-like fissure. 



The right area of the superior surface is convex and extensive, and lies in contact with the 

 diaphragm, which separates it from the inner surface of the lower ribs, and also, above, from the 

 inferior margin of the lung and pleura. Though sharply marked off by the inferior margin from 

 the visceral surface, it passes without distinct limits into the other areas of the parietal surface. 

 It is completely covered by peritoneum. 



The superior surface is smooth and shows no fissures, but the line of attachment of the 

 ligamentum falciforme is taken as dividing the liver on this surface into a right and a left lobe. 



Upon the posterior surface and inferior surface there are several clefts or depressions upon 

 the surface of the liver, termed fossae or fissures, which further subdivide the surfaces into lobes. 



These fossae, it should be noted, do not indicate any deep division of the liver into separate 

 parts, but are only indentations upon the surface. 



Porta Hepatis. (1) The gate of the liver (O.T. portal or transverse fissure) is the 

 equivalent in the liver of the hilum of other glands. It is a slit-like depression, 

 where the vessels enter the gland, and whence the ducts emerge. 



It is placed on the inferior surface, runs transversely from right to left, and 

 measures about 2 to 2J inches in length. It is bounded anteriorly and posteriorly 

 by prominent margins, and through it the hepatic artery, vena portse, and hepatic 

 plexus of nerves enter the liver, and the hepatic ducts and many of the lymph 

 vessels leave. To the anterior and posterior margins of the fissure are attached 

 layers of peritoneum which constitute part of the lesser omentum. 



The various structures found in the porta hepatis are arranged in the following 

 way. The vena portse lies posteriorly, and divides, in the fissure, into right and 

 left branches, which run to right and left. The neck of the gall-bladder, with the 

 cystic duct coming from it, lies at the right extremity of the fissure, and there the 

 cystic duct bends downwards between the layers of the hepato-duodenal ligament. 



The right and left bile ducts lie at their respective ends of the porta hepatis, 

 and converge towards each other at the right extremity and lie anterior to the 

 corresponding branches of the hepatic artery, and to the right side of the main 

 vessel at their junction in the hepato-duodenal ligament. The nerves mainly 

 invest the arteries, and the lymph vessels lie in the connective tissue which invests 

 all these structures. 



Two or three lymph glands are occasionally found in the porta hepatis, especially 

 at the right end, near the neck of the gall-bladder, and when enlarged, they may 

 press upon the ducts, and interfere with the passage of the bile. 



The intervals between the vessels and other structures are filled in by loose 

 connective tissue, which is continued inwards with the vessels as the fibrous capsule 

 of Glisson. 



When the porta hepatis is opened up, it is found to extend on the left as far as 

 to the fossa vense umbilicalis. 



