THE URINARY ORGANS. 



625 



eruli is the swelling of the cells which cover the capillaries. ' These cells 

 which in normal conditions are thin and scarcely visible, save by their 

 nuclei, now project from the capillary loops, sometimes remaining closely 

 apposed to the capillary walls, sometimes assuming polypoid shapes 

 (Fig. 385), sometimes forming a continuous thick covering of cuboidal 

 cells over the vessels. The nuclei are larger than normal and mitosis 

 may be evident. Similar changes occur in the epithelium between the 

 capillary loops. The capillaries are sometimes distended and plugged 

 with cells ; some of these are leucocytes ; others are larger with large 

 nuclei and may be swollen endothelium. Hyaline thrombi are often 

 found in these tuft capillaries. The swollen and proliferating tuft epi- 

 thelia often undergo fatty degeneration and may peel off into the glom- 

 erular space. 



In some cases the proliferation and exfoliation are extensive and 

 the cells may collect in crescentic masses within Bowman's capsule, 

 crowding the tuft toward 

 its hilus. The cells in these 

 crescentic masses may be 

 flattened from pressure and 

 in profile appear fusiform 

 (Fig. 386). The capsular 

 epithelium may be swol- 

 len or remain apparently 

 intact while there is a large 

 cell accumulation from the 

 tuft ; or it may proliferate 

 or become fatty or peel off. 

 Swelling, exfoliation, and 

 proliferation of the glomer- 

 ular epithelium in some de- 

 gree are of frequent occur- 

 rence in acute nephritis. 

 They are sometimes so pro- 

 nounced, especially in acute 

 nephritis following scarla- 

 tina, either with or with- 

 out extensive associated lesions as to have suggested a name for one 

 phase of the lesion glomerulo-nephritis. There is sometimes a considera- 

 ble accumulation of albuminous exudate between the tuft and capsule. 

 Such albuminous material in specimens fixed by alcohol is in the form of 

 fine granules and may be mingled with exfoliated and often fatty epithe- 

 lium or cell detritus. 



Leucocytes and red blood cells may be present with other exudate 

 within Bowman's capsule. 



1 For a study of the development of the glomeruli and its relation to pathological 

 changes see Herring, Jour. Path, and Bact., vol. vi., p. 459, 1900. 

 40 



FIG. 386. ACUTE DIFFUSE NEPHRITIS FOLLOWING 

 SCARLATINA. 



Swollen cells are seen upon the capillary tuft and lining 

 Bowman's capsule. Polyhedral and flattened cells lie in masses 

 between the capsule and the tuft ; the latter has been pressed 

 upon by the cells and other exudate within the capsule. 



