GALL BLADDEE AND BILE DUCTS. 411 



Carcinoma of the liver can extend along the lymphatics of the 

 round ligament, and so may give rise to secondary nodules at 

 the umbilicus. It may also infect the glands in the portal 

 fissure, and so produce jaundice and ascites. 



Sarcoma, which is of rare occurrence primarily within the 

 portal area, is equally rare in the liver as a secondary growth. 



DISEASES OF THE GALL BLADDER AND BILE DUCTS. 



The bile duct opens into the duodenum on the tip of a small 

 nipple-like projection, which is sometimes known as the papilla 

 of Yater. Within the papilla, whilst traversing the duodenal 

 wall, the duct presents a terminal dilatation which usually, but 

 not always, receives the termination of the main duct of the 

 pancreas. The dilated portion of the duct is known as the 

 ampulla of Vater. The papilla is situate on the inner and 

 posterior, aspect of the descending portion of the duodenum, 

 about four inches from the pylorus. Infection from the duo- 

 denum can gain access to the common duct through the papilla, 

 and ascend through the cystic duct to the gall bladder, or through 

 the hepatic ducts to the liver. The pancreatic duct may be 

 infected at the same time on account of its relation to the 

 ampulla. 



The cystic duct near its junction with the gall bladder 

 describes an S-shaped curve, and this, together with the dupli- 

 catures of mucous membrane which form Heister's valve, accounts 

 for the ease with which it is obliterated by inflammatory changes 

 in its mucous membrane. When the cystic duct is obstructed in 

 this way, the gall bladder becomes distended with the mucous 

 secretion of its own glands. 



The fundus of the gall bladder usually projects against the 

 abdominal wall at the upper part of the right linea semilunaris, 

 and when the viscus is distended, may be felt as a rounded and 

 superficial tumour at the outer border of the right rectus muscle, 

 just internal to the ninth costal cartilage (Fig. 49, p. 362). Unless 

 it is firmly fixed by inflammatory lesions, the gall bladder follows 



