THE URINARY ORGANS. 



619 



are formed may be mingled with the products of degeneration and disin- 

 tegration of epithelial cells, either from the glomeruli or from the tubules ; 

 or with red blood cells, or leucocytes, or exfoliated epithelial cells. In 

 this way granular casts, epithelial casts, blood casts, etc., are formed. The 

 epithelium of the tubules may peel off in masses, forming cast -like cell 

 structures. Homogeneous globules of various sizes may be formed in 

 the tubular epithelium which is yet in place, and as the cells degenerate 



FIG. 379. HYALINE CASTS IN URINIFEROCS TUBULE. 

 The epithelium is flattened in the tubules containing the casts. 



and disintegrate, such homogeneous globules may collect in the lumina 

 of the tubules (Fig. 378) or they may fuse to form hyaline casts (Fig. 

 379). Homogeneous casts giving the micro-chemical characters of amy- 

 loid are of occasional occurrence in the tubules. 



Casts and cell detritus may form both in the cortical and medullary 

 tubules and may pass out of the organ with the urine. 



DEGENERATION. 



Albuminous Degeneration (Parenchymatous Degeneration Acute Degen- 

 eration). This form of degeneration is most common in the acute infec- 

 tious diseases, such as diphtheria, scarlatina, measles, typhoid fever, yel- 

 low fever, and in many forms of septicaemia and toxseniia. It usually 

 accompanies similar lesions in other viscera. In moderate degrees of 

 the lesion, the epithelium, particularly of the convoluted tubules, is 

 swollen and more coarsely granular than normal (Fig. 380). In more 

 pronounced lesions iu addition to simple albuminous degeneration the 

 epithelium may become more or less filled with minute fat droplets, or 

 the cells may disintegrate and peel off, or they may become necrotic and 

 the nuclei fail to stain. The cell body may then undergo coagulation or 

 disintegrate. 



