130 RELATIONS OF BACTERIA TO DISEASE. 



EFFECTS OF BACTERIAL ACTION. 



These may be for convenience arranged in a tabular 

 form as follows : 



Tissue Changes. 



(1) Local changes, i.e., changes produced in the neigh- 



bourhood of the bacteria. 



Position (a) At primary lesion. 

 (b) At secondary foci. 



Character (a) Vascular changes and tissue^ . 



reactions. ^ ute . or 



(b) Degeneration and necrosis. J C 



(2) Produced at a distance from the organisms by 



absorption of toxines. 



(a) In special tissues, i.e., nerve fibres, secreting cells, 



vessel walls, etc. 



(b) General effects of malnutrition, etc. 



Symptoms. 



(a) Associated with known tissue changes. 



(b) Without known tissue changes. 



Tissue Changes Produced by Bacteria. The action o 

 bacteria on the tissues will be more minutely described in 

 connection with the special diseases, but here a general out 

 line of their more important effects may be given. These 

 effects are so various as to include almost all known patholo 

 gical changes, but they may be classified as local effects or 

 lesions produced in the neighbourhood of the bacteria, and 

 general changes which are produced in various parts of the 

 system by the circulation of the bacterial products. A 

 already stated, both the local and the general effects are 

 due to the products of the organisms, but the substance 

 which produce local disturbances may not be the same ii 

 more concentrated form as these which act on distant part 

 of the system. In diphtheria, for example, the product 



