278 * ACTIONS OF THE INTESTINAL JUICE. 



(fig. 201, 4), so that there is a loop of intestine supplied by its blood-vessels and nerves, isolated 

 and with an upper and lower aperture.] 



The intestinal jnice of such fistulge flows spontaneously in very small amount, 

 and is increased during digestion; it is increased especially its mucus by 

 mechanical, chemical, and electrical stimuli ; at the same time, the mucous 

 membrane becomes red, so that 100 centimetres yield 13 to 18 grammes of this 

 juice in an hour (Thiry). The juice is light yellow, opalescent, thin, strongly 

 alkaline, specific gravity 1011, evolves C0 2 when an acid is added; it contains 

 albumin, ferments, and mucin especially the juice of the large intestine. Its 

 composition is water, 97*59; proteids, 0'80; other organic substances = 0*73; salts, 

 0*88 per cent. ; amongst these sodium carbonate, 0*32 to 0*34 per cent. 



[The intestinal juice obtained by Meade Smith's method contained only '39 per cent, of 

 organic matter, and in this respect agreed closely with the juice which A. Moreau procured by 

 dividing the mesenteric nerves of a ligatured loop of intestine. The secretion of the large 

 intestine is much more viscid than that of the small intestine.] 



Actions of Succus Entericus. It is most active in the dog, and in other animals 

 it is more or less inactive. 



(1) It is less diastatic than the saliva and the pancreatic juice, but it does not 

 form maltose ; while the juice of the large intestine does not possess this property 

 (Eickfiorst). 



(2) It converts maltose into grape-sugar. It seems, therefore, to continue the 

 diastatic action of saliva ( 148) and pancreatic juice ( 170), which usually form only- 

 maltose. 



According to Bourquelot this action is due to the intestinal schizomycetes and not to the 

 intestinal juice as such, the saliva, gastric juice, or invertin. The greater part of the maltose 

 appears, however, to be absorbed unchanged. 



(3) Fibrin is slowly (by the trypsin and pepsin Kiihne) peptonised (Thiry, 

 Leube) ; less easily albumin (Masloff), fresh casein, flesh raw or cooked, 

 vegetable albumin ; probably gelatin also is changed by a special ferment into a 

 solution which does not gelatinise (Eichhorst). 



(4) Fats are only partly emulsionised (Schif), and afterwards decomposed 

 (Vella). 



(5) According to CI. Bernard, invertin occurs in intestinal juice (this ferment 

 can also be extracted from yeast). It causes cane-sugar (C 12 H 22 O n ) to take up 

 water ( + H 2 0), and converts it into invert-sugar, which is a mixture of left rotating 

 sugar (laevulose, C 6 H 12 6 ) and of grape-sugar (dextrose, C 6 H 12 O c ). Heat seems to 

 be absorbed during the process. 



[Hoppe-Seyler has suggested that this ferment is not a natural product of the body, but is 

 introduced from without with the food. Matthew Hay, however, finds it to be invariably present 

 in the small intestine of the foetus.] 



[Effect of Drugs. The subcutaneous injection of pilocarpin causes the mucous membrane of 

 a Vella's fistula to be congested, when a strongly alkaline, opalescent, watery, and slightly albu- 

 minous secretion is obtained. This secretion produces a reducing sugar, converts cane-sugar 

 into invert-sugar, emulsifies neutral fats, ultimately splitting them up, peptonises proteids, and 

 coagulates milk, even although the milk be alkaline. The jnice attacks the sarcous substance 

 of muscle before the connective-tissues the reverse of the gastric-juice. The mucous mem- 

 brane in a Vella's fistula does not atrophy. K. B. Lehmann finds that the succus entericus 

 obtained from the intestine of a goat by a Vella fistula has no digestive action.] 



The Action of Nerves on the secretion of the intestinal juice is not well determined. Section 

 or stimulation of the vagi has no apparent effect ; while extirpation of the large sympathetic 

 abdominal ganglia causes the intestinal canal to be filled with a watery fluid, and gives rise to 

 diarrhoea. This may be explained by the paralysis of the vaso-motor nerves, and also by the 

 section of large lymphatic vessels during the operation, whereby absorption is interfered with 

 and transudation is favoured. Moreau's Experiment. Moreau placed four ligatures on a loop 

 of intestine at equal distances from each other (fig. 202). The ligatures were tied so that three 

 loops of intestine were shut off. The nerves (N) to the middle loop were divided, and the 

 intestine was replaced in the abdominal cavity. After a time, a very small amount of secretion, 

 or none at all, was found in two of the ligatured compartments of the gut, i.e., in those with 

 the nerves and blood-vessels intact (1, 3), but the compartment (2) whose nerves had been 



