CHAP. IV.] THE PRESSURE UNDER WHICH THE BILE IS SECRETED. 287 



saliva, is very low (Friedlander u. Barisch 1 ). If, however, we contrast 

 the pressure under which the bile is secreted with the blood-pressure 

 in the portal vein we obtain results which are in accordance with 

 those ascertained in the case of the salivary glands. 



Heidenhain 2 , measuring simultaneously the pressure under which 

 bile is secreted and the pressure in a branch of the inferior mesen- 

 teric vein of dogs, found that the bile-pressure invariably exceeded 

 the portal blood-pressure by a considerable amount. In the follow- 

 ing table are stated his results, the pressure being expressed in terms 

 of a column of solution of sodium carbonate. 



TABLE EXHIBITING THE RELATION BETWEEN THE PRESSURE UNDER 

 WHICH THE BILE WAS SECRETED AND THE PRESSURE IN THE 

 SUPERIOR MESENTERIC VEIN IN FIVE EXPERIMENTS ON THE DOG. 

 (HEIDENHAIN.) 



Taking the arithmetic mean of the ratios of bile-pressure : blood- 

 pressure in these five experiments it appears that the former was 

 nearly twice and a half as great as the latter (2'45 : 1). 



Re-absorp- If the outflow of bile be prevented as by the appli- 



tion of secreted cat i on o f a ligature to the common bile-duct, or through 

 its occlusion by a gall stone or a plug of mucus, the 

 bile already secreted is rapidly re-absorbed. The biliary constituents 

 ultimately pass into the blood and are excreted by the urine. If 

 their amount be sufficiently large, however, the colouring matter 

 soon stains the conjunctiva and later the skin, the condition of 

 ictorus or jaundice being established. 



Researches conducted, under Lud wig's direction, by Fleischl 3 led 

 to the interesting discovery that the bile is not re-absorbed by the 

 blood-vessels of the liver, but by the lymphatics of the organ, whence 



1 v. Friedlander und C. Barisch, ' Zur Kenntniss der Gallenabsonderung ' (aus d. 

 phys. Institut zu Breslau), Archiv f. Anat. u. Phys. 1860, see p. 659 et seq. 



2 Heidenhain, original experiments published in his article 'Gallenabsonderung,' 

 Hermann's Haridbuch, Vol. v. I. p. 269. 



3 Fleischl, ' Von der Lymphe und den Lymphgefassen der Leber,' Ludwig's 

 Arbeiten, 1874, p. 24. 



^ 



OF THE A 



UNIVERSITY) 



s 



