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PRINCIPLES OF VETERINARY SCIENCE 



flow at once into the general circulation. Death from auto- 

 intoxication will shortly follow. 



The lacteal vessels run between the folds of mesenteries and 

 empty their contents into the receptaculum chyli. This reservoir 

 is drained by the thoracic duct, which in turn empties into one 

 of the large veins that discharges its flow into the right auricle 

 (see Figs. 26 and 31). There are lymph glands, on the course of 

 the lacteals in the mesenteries, through which the chyle is filtered 

 and by which any foreign particles that may have been absorbed 

 from the intestines are removed. 



Fig. 31. — Diagrammatic representation of the two paths of absorption: V., 

 Veins of the mesentery whicfli unite to form the portal vein, P.V.; H.V., hepatic 

 vein; P.V.C., posterior vena cava; L., lacteals which convey through mesenteric 

 lymph-glands, M., to the receptaculum chyli, R.C.; L.J.V., left jugular vein; 

 R.J. V., right jugular vein; B.V., brachial vein; A.V.C., anterior vena cava. 



I. Materials Absorbed by the Blood-vessels. — These are of 

 various kinds and may be divided into two groups, viz., those 

 that are of use to the body and those that are harmful to the 

 body. The first group is composed of amino-acids, glucose, water, 

 and mineral substances. The second group consists of ammonia 

 and certain other toxic materials. 



Amino-acids comprise a number of organic substances, among 

 which are aspartic acid, arginin, cystin, histidin, leucin, lysin, 

 phenylamin, prolin, tryptophan, and tyrosin. When any one 

 of these is lacking in the ration, starvation will result. They 

 represent the last stage in protein digestion; further cleavage 

 would probably render the nutrients unsuitable for use by the 



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