CIEEHOSIS OF THE LIVEE. 407 



Engorgement of the various tributaries to the portal vein 

 has been supposed to produce the various signs and symptoms of 

 cirrhosis of the liver in a purely mechanical way. On this 

 assumption, congestion of the gastric tributaries is responsible for 

 dyspepsia, nausea, and haematemesis ; congestion of the splenic 

 vein for splenic enlargement and anaemia; congestion of the 

 superior mesenteric vein for ascites ; and congestion of the 

 haemorrhoidal vein for haemorrhoids. The matter, however, is 

 not so simple as this, although it is certain that the splenic 

 enlargement may very much diminish when the portal system 

 is depleted by the result of haemorrhage from the oesophageal, 

 gastric or haemorrhoidal veins, or by profuse diarrhoea. Throm- 

 bosis of the portal vein, on the other hand, may be followed by 

 great increase in the size of the spleen and ascites. 



The ascites in some cases has been supposed to be due to 

 thrombosis of small radicles of the portal vein or of its compen- 

 satory communications. This, however, remains to be proved. 

 The effusion is possibly due to a further catarrhal swelling of the 

 liver cells, which strangles the small portal radicles owing to the 

 resistance of the fibrous tissue in which the lobules are enmeshed. 



The accumulation of fluid in ascites exercises pressure on the 

 large renal and iliac trunks, causing albuminuria and cedema of 

 the legs, which sometimes extends to the lower part of the 

 abdominal wall, but similar results may arise from the 

 cardiac degeneration which so often accompanies cirrhosis. 



The effusion also interferes with the action of the diaphragm, 

 leading to dyspncea, collapse of the lung bases and irregularity 

 in cardiac action. The shifting dulness of ascites may be simu- 

 lated by a loaded colon if that be provided with a long mesentery, 

 but may be distinguished by the fact that the gain of resonance 

 in the uppermost flank is not accompanied by a corresponding 

 loss of resonance in the flank which is lowermost. 



The inferior vena cava, although embedded in a depression at 

 the back of the liver, is rarely exposed to much compression. 



The indications of enlargement of the liver have been con- 

 sidered already. The normal vertical extent of liver dulness 



