BILIARY FISTULA. 



271 



muscles of the trunk during vigorous exercise, diminishes the secretion, while the transfusion 

 of large quantities of blood increases it, but if too high a pressure is caused in the portal vein, 

 by introducing blood from the carotid of another animal, it is diminished. . 



(g) Influence of Nerves. All conditions which cause contraction of the abdominal blood- 

 vessels, e.g., stimulation of the ansa Vieussenii, of the inferior cervical ganglion, of the hepatic 

 nerves, of the splanchnics, of the spinal cord (either directly by strychnia, or reflexly through 

 stimulation of sensory .'nerves), affect the secretion ; and so do all conditions which cause stagna- 

 tion or congestion of the blood in the hepatic vessels (section of the splanchnic nerves, diabetic 

 puncture, 175), section of the cervical spinal cord. Paralysis (ligature) of the hepatic nerves 

 causes at first an increase of the biliary secretion. 



(h) Portal and Hepatic Veins. .With regard to the raw material supplied to the liver by its 

 blood-vessels, it is important to note the difference in the composition of the blood of the 

 hepatic and portal veins. The blood of the hepatic vein contains more sugar (?), lecithin, 

 cholesterin (Drosdoff), and blood-corpuscles, but less albumin, fibrin, haemoglobin, fat, water, 

 and salts. 



[(i) Uffelmann observed that the flow of bile from a person with a biliary fistula was arrested 

 during fever.] 



(6) The formation of bile is largely dependent upon the decomposition of red 

 blood-corpuscles, as they supply the material necessary for the formation of some 

 of its constituents. 



Hence, all conditions which cause solution of the coloured blood-corpuscles are accompanied 

 by an increased formation of bile ( 180). 



(7) Of course a normal condition of the hepatic cells is required for a normal 

 secretion of bile. 



Biliary Fistulse. The mechanism of the biliary secretion is studied in animals by means of 

 biliary fistulse. Schwann opened the belly by a vertical incision a little to the right of the 

 ensiform process, cut into the fundus of the 

 gall-bladder, and sewed its margins to the edges 

 of the wound in the abdomen, and afterwards 

 introduced a cannula into the wound (fig. 197). 

 To secure that all the bile is discharged exter- 

 nally, tie the common bile-duct in two places and 

 divide it between the two ligatures. After a fistula 

 is freshly made the secretion falls. This depends 

 upon the removal of the bile from the body. If 

 bile be supplied, the secretion is increased. Re- 

 generation of the divided bile-duct may occur in 

 dogs. V. Wittich observed a biliary fistula in 

 man. [A temporary biliary fistula may also be 

 made. The abdomen is opened in the same 

 way as described above. A long bent glass . , L *? \, '" 7 -, 



cannula is introduced and tied into the common Schwann s permanent fistula, and a temporary 



fistula. Abd, abdominal wall ; G.b., gall- 

 bladder; INT., intestine ; T, tube in tempo- 



rary fistula {Stirling). 



bile-duct, and the cystic duct is ligatured or 

 clamped (fig. 197). The tube is brought out 

 through the wound in the abdomen.] 



[Influence of the Liver on Metabolism. If the liver be excluded from the circulation, im- 

 portant changes must necessarily occur in the metabolism. In birds (the goose) there is an 

 anastomosis between the portal system of the liver and that of the kidneys, so that, when the 

 portal circulation is interrupted in these animals, there is never any great congestion in the 

 abdominal organs. The goose dies generally eight to ten hours after the operation. The uric 

 acid in the urine rapidly falls to a minimum (^\ to -fa of normal) ; the chief constituent of the 

 urine is then sarcolactic acid, while in normal urine there is none ; the ammonia is increased 

 (Minkowski). This experiment goes to indicate that uric acid is formed in the liver. Dog. 

 If the liver be excluded from the portal circulation, by connecting the portal vein with the 

 inferior vena cava, and ligaturing the hepatic artery, a dog will live in the former case three to 

 six days and in the latter one to two. The liver does notnindergo necrosis, nor does bile cease 

 to be secreted. The liver is nourished by the blood in the hepatic vein, the reflux in this vein 

 being probably caused by the respiratory movements (Stolnikow). Noel Paton finds that in dogs, 

 in a condition of nitrogenous balance, some drugs which increase the flow of bile (e. g. , salicylate 

 and benzoate of soda, colchicum, perchloride of mercury, and euonymin) also increase the pro- 

 duction of urea ; hence, he concludes that the formation of urea in the liver bears a very direct 

 relationship to the secretion of bile ( 256).] 



179. EXCEETION OF BILE. [In this connection we must keep in view two 

 distinct mechanisms. (1) The bile-secreting mechanism dependent upon the 



