KIDNEY. 109 
glomeruli supplied by an affected artery are usually compressed by the 
growth of capsular cells. After a time there may be a growth of con- 
nective tissue in the stroma between these wedges. The exudation 
from the bloodvessels is marked and the urine contains a quantity of 
albumen, many casts, red and white-blood cells. 
Describe the changes produced in chronic congestive nephritis. 
The kidneys are uniformly congested. The tubular epithelium is 
opaque, flattened or swollen, especially in the cortical portion of the 
kidney. The glomerular capillaries are dilated, and their walls 
thickened by the swelling of the cells which cover them. The kidney 
may be of medium size or increased in size, and its weight is increased. 
What changes are found in chronic degenerative nephritis ? 
This condition is produced by long-continued disturbances of circu- 
lation, heart disease, etc. As a rule, the kidney is increased in size. 
The epithelium lining the tubules in the cortical portion of the kidney 
is swollen, coarsely granular and infiltrated with fat. If the lesion is 
due to a disturbance of circulation, the glomerular capillaries are 
dilated. There may bea slight exudation from the bloodvessels, but 
there are no changes in the stroma or arteries. 
What changes are seen in chronic diffuse nephritis with exudation? 
Usually the kidney is increased in size, but some are found that 
are smaller than normal. The surface may be smooth, nodular or 
granular. The cortex may be white or gray, mottled at times with 
yellow, gray, or red patches. From the bloodvessels there is a marked 
exudation, the products of which are found in the tubules, unless it 
has been carried off in the urine. 
The tubules may be dilated and their lining epithelium flattened, or 
the epithelium may be degenerated and the tubule atrophied. Some- 
times the tubules are filled with cast matter, or contain extravasated 
blood. There is a marked increase of the connective tissue of the 
stroma of the kidney. 
The glomerular capillaries may be the seat of waxy degeneration. 
The arterial walls are thickened. 
What changes are seen in chronic diffuse nephritis without 
exudation ? 
The changes are the same as in the preceding variety with the 
exception that the exudative products are absent. The kidney is 
usually atrophied but may be much increased in size. The increase 
in connective tissue is marked. Clinically these cases run a much 
slower course than the preceding class. 
