BILIARY FISTULA. 361 



(/.) Profuse loss of blood arrests the secretion of bile, before the muscular and 

 nervous apparatus become paralysed. A more copious supply of blood to other 

 organs e.g. , to the muscles of the trunk during vigorous exercise, diminishes the 

 secretion, while the transfusion of large quantities of blood increases it (Landois); 

 but if too high a pressure is caused in the portal vein, by introducing blood from 

 the carotid of another animal, it is diminished (Heidenhain). 



({/.) The 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 (Afanassiew) 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 stagnation or 

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

 diabetic puncture, 175), section of the cervical spinal cord (Heidenhain). Par- 

 alysis (ligature) of the hepatic nerves causes at first an increase of the biliary 

 secretion (Afanassieff). 



(h.) 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. 



(6.) The formation of bile is largely dependent upon the decomposi- 

 tion of coloured 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 Fistulae. The mechanism of the biliary secretion is studied in animals 

 by means of biliary fistulee. 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. As a rule all the bile is discharged externally; 

 but to be quite certain that this is so, the common bile-duct ought to be tied between 

 two ligatures, and divided. 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. Regeneration of the divided bile-duct may occur in dogs. 

 v. Wittieh 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 cannula is introduced and tied into the common bile-duct, and the cystic 

 duct is ligatured or clamped. The tube is brought out through the wound in the 

 abdomen. Necessarily all the bile must be discharged by the tube]. 



179. Excretion of Bile, 



[In connection with the excretion of bile, we must keep in view two 

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

 the liver-cells, which are always in a greater or less degree of activity; 

 (2) the bile-expelling mechanism, which is specially active at certain 

 periods of digestion (p. 360).] 



