Page:The New International Encyclopædia 1st ed. v. 12.djvu/392

* LIVER. 348 LIVER. blood which has been brought from the intestines by the portal vein, and that, indeed, the principal oHice of the liver was to separate effete matter from this portion of the venous sj'stem; but many experiments which have been made since Bernard discovered the glycogenic function of the liver go to show this idea erroneous. It has also been thouglit that the hepatic artery may furnish material for the secretion of bile, w'hile the portal vein furnished that for the production of sugar; but these views again are quite over- thrown by many well-established facts and ex- periments. It has been found that, after the ligation of the hepatic artery, bile has been secreted from blood furnished by the portal vein; and again, according to the experiments of Ore, who has succeeded in gradually obliterating the portal vein without immediately producing death, it has been found that bile is secreted from blood furnished by the hepatic artery. In one in- stance in which a patient died of dropsy the portal vein was obliterated, and yet the gall- bladder was full of bile. Anomalous eases have been reported where the portal vein, instead of passing through the liver, emptied into the as- cending vena cava, and where also there was found no deficiency of bile. These facts point to the conclusion that the .secretory elements of the liver have an elective power, and that this gland may elaborate its products either from venous or arterial blood. The only conclusion, therefore, is that the liver produces bile from both the por- tal vein and the hepatic artery, and that the secretion may be kept up if either one of these vessels be obliterated. The natural color of bile is variable; in the pig it is bright yellow; in the dog, dark brown ; and in the ox. greenish yellow. In general, it may be stated that it is dark green in carnivorous, and greenish yellow in herbiv- orous animals. Its specific gravity is variously stated. Some authorities place it at 102C>; others from 1020 to 1026; and again others from 102G to 10.31. These differences are considerable, but the numbers were prol)ably the result of exact observation, as the bile is found to differ under different circumstances. (See table.) Fresh bile is nearly inodorous, but after being taken from the body of an animal it soon undergoes putre- factive changes. It has been generally thought to be invariably alkaline, and this is true of that which is found in the hepatic duct, but it often has an acid reaction after it has passed into the gallbladder. The bile contains two classes of constituents. one of which are true secretions, and destined to reenter the system and perform certain functions. They contain, with other matters, some that are formed in the liver, and are no doubt elaborated from materials furnished by the blood. These are the salts included in the accompanying table under the names of taurocholate and glycocholate of soda. Biliverdin, the coloring matter of the bile, is probably a mixture of different coloring principles which undergo rapid change on ex- posure to the a4r. It has some analogy to the coloring matter of the blood, and it is also, like the biliary salts, supposed to be formed in the liver. This coloring matter has intense power, and in eases of obstruction of the biliary passages will give the skin and conjunctivae a decidedly yellow color. Like hfemoglobin, it contains a portion of iron, but the relative amount has never been ascertained. The other constituents of the bile are truly excretory, being composed of effete matter brought by the blood-vessels from the various parts of the system. In this class is cholesterin, which has long been known as a constituent of the bile, whose chemical and physical characteristics were well recognized, but whose physiological relations were not under- stood. (See Cholesterin.) In regard to the glycogenic function of the liver, it may be stated that nearlj- all physiologists admit that Bernard demonstrated it completely, al- though for a long time many apparently well- made experiments seemed to throw great doubt on the subject, some believing that the sugar C0.MPO8IT10N OP THE Bile Accobdujq to Robin Water Taurocholate of soda Glycocholate of soda Chulest^Tin Biliverdin Lecithene Margarin, olem, and traces of soaps Cholin Chloride of sodium Phosphate of soda Phosjihate of potassa Phosphate of lime Phosphate of majrnesia '..... Salts of iron... Salts of manganese Silicic acid Mucosine Loss 916.00 to 819.00 56.50 •• 106.00 traces. 0.6'i to 2.66 14.00 •• 30.00 3.20 traces. 2.77 to 1.60 •• 0.75 " 0.50 " 0.45 ■' 0.15 ■• traces '* 0.03 •• traces. 3.43 to 31.00 3.50 2.50. 1.50 1.35 0.80 0..TO 0.12 0.06 1.21 1000.00 1000.00 found by Bernard was a product of postmortem changes. It is a fact that it is ditficult to find sugar in the liver which may not be said to be produced after death; consequently, demonstra- tive experiments are exceedingly difficult. On ex- amining the blood which comes from the lungs in animals upon which vivisection has been per- formed it is found to contain no sugar. Other experiments have left no doubt of the fact that, to serve some purpose in the animal economy, sugar is destroyed in its passage through tlu' lungs, the most generally received view beiiii: that it is converted into lactic acid, which unitc< with the alkalies in the blood to form lactate--, which again are converted into carbonates. It i^ thought that among the causes of the disea-r diabetes is an abnormal performance of the fiun tion of respiration (q.v.). The glycogenic mat- ter of the liver, in composition, reactions, and particularly in its readiness to be transformed into sugar, has considerable resemblance to starch, and is called by some authors amyloid matter. On account of its insolubility in water it may be extracted from the liver after all the sugar has been washed out. See Lix^er, Diseases OF THE. Consult: Morris, Human Anatomy (Phila- delphia, 1902) ; Flint, The Physiology of Man (New York, 187.5); and Flint. The Excretory Function of the Liver (Philadelphia, 1877). LIVER, Diseases of the. The liver is sub- ject to a number of disorders, circulatory, in- flammatory, and infectious, some of which origi- nate in the organ itself, while others arise from disorders in other parts of the body. It is in- timately concerned with the processes of assimi- lation and elaboration of food, and dietary indis- cretions, especially if long continued, are certain to affect the health of the organ unfavorably. Biliousness is an unscientific and inaccurate term used to designate a condition which presents