THEORETICAL CONCLUSIVE CONSIDERATIONS 561 



Theoretical Conclusive Considerations 



Before I finally turn to the question as to what signification the internal 

 secretion of the pancreas has for the pathogenesis of human diabetes, I 

 should like briefly to summarize the most important points that were touched 

 upon in the course of the exposition. 



1. Embryology, anatomy, experimental pathology, and clinical observa- 

 tion point to a certain independence of the insular apparatus. The em- 

 bryological investigations showed that the insular apparatus and the acini 

 developed separately. The anatomical investigation showed a different struc- 

 ture of these two apparatus; a transition of the one tissue-element into the 

 other has not up to the present been demonstrated with certainty. The ex- 

 perimental pathological investigations showed that after ligation of the excre- 

 tory ducts the acini become destroyed, while the insular apparatus for the most 

 part behaves refractorily. The pathological-anatomical observation likewise 

 showed that on the one hand the insular apparatus ordinarily is more resistant 

 to certain destructive processes and that on the other, isolated alterations of 

 the insular apparatus occur; finally clinical observations showed that dis- 

 turbances in the function of the glandular apparatus and the insular appara- 

 tus occur entirely apart from each other, and that to such isolated disturb- 

 ances a corresponding pathological-anatomical finding can with probability 

 be ascribed. 



2. After the complete extirpation of the pancreas always occurs (in the 

 dog) a characteristic disturbance of metabolism; there always develops a 

 severe diabetes Jeading to death, in the course of which affection the glyco- 

 genesis is to a high degree, but not entirely, prevented in the liver and 

 muscles; the disturbances in the assimilation of sugar might lead immediately 

 to a disturbance in the combustion of sugar. In addition to this disturbance 

 in anabolism exists a severe disturbance in catabolism, that affects not only 

 the carbohydrate metabolism (increased sugar production), but also the 

 protein, fat, and salt, metabolism. The catabolic disturbance shows, on 

 extirpation of the pancreas, great regularity; there further exists regularly a 

 certain hyperexcitability of the sympathetic nerves. 



3. The investigation of the metabolism in human diabetes shows disturb- 

 ances in both anabolism and catabolism; the latter, however, confine them- 

 selves only to the sugar metabolism, while quantitatively increased breaking 

 up of albumin and fat are not demonstrated even in the severer cases. On 

 the contrary, catabolic disturbances in the sugar metabolism are much 

 more severe in the graver cases, as the glycosuria attains a much greater 

 intensity than in the dog without a pancreas. 



4. Concerning the nervous manifestations in human diabetes, we can 

 distinguish two types, between which we find all possible transitions. In the 

 first, rarer, type, to which v. Noorden has lately directed attention, the nerv- 



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