152 THE ABDOMEN. 



been proved, that urea, the end-product of protein 

 metabolism, which is brought by the blood to the kidneys 

 and there excreted, is formed in the liver. At any rate, 

 urea is formed not only from the nitrogenous food eaten 

 but from the metabolism of protein substances in the 

 tissues, being purely a waste product, from which the 

 nutritious substances have been absorbed. The amount 

 thrown off is an accurate gauge of the amount of protein 

 metabolism going on. The process of its manufacture 

 is doubtless very complex. 



Ptosis or dropping of the liver sometimes occurs and is 

 due to the stretching of the ligaments. Rupture is 

 common, generally as the result of a fall from a height, 

 on account of its size and friability. The liver is also 

 subject to many diseases. Cirrhosis occurs in people 

 who drink a good deal and in its later stages is accom- 

 panied by ascites, an accumulation of fluid in the ab- 

 dominal cavity. When there is a general accumulation of 

 fluid throughout the body it is known as anasarca. 

 Syphilis causes enlargement of the liver. Abscesses 

 occur, perhaps oftener in the tropics than farther 

 north, and may break into the lungs, stomach, or 

 intestine. 



The Gall-bladder. The gall-bladder, which is simply 

 a reservoir for the bile, is a pear-shaped organ three inches 

 long and one inch broad. It lies in a fossa on the under 

 side of the liver, with the large end or fundus touching 

 the abdominal wall just below the ninth costal cartilage. 

 Here it can be felt as a small mass in empyema of the 

 gall-bladder. Normally it holds a little over one ounce, 

 but with occlusion it may become stretched. Its duct 

 is the cystic duct, which joins the hepatic duct in the 

 common bile duct, but bile only passes up into the gall- 

 bladder when the opening into the duodenum is closed, 

 that is, between meals. 



If one of the bile ducts is stopped up by a stone or 

 cancer or for any other cause, the bile backs up in the 

 liver, the pigments are absorbed into the circulation, 



