MORBID ANATOMY - CHRONIC CONGESTION OF THE KIDNEYS.
The kidneys are of medium size, or rather large. Their weight is increased somewhat out of proportion to the increase in size. The color is dark-red, the consistence is very hard, the are smooth, the capsules are not adherent. The congestion is most marked in the veins of the pyramids ; they contain an increased quan tity of blood, and are often dilated. The capillaries of the cortex are also congested, but it is rather exceptional to find them dilated. The epithelium of the convoluted tubes is swollen, and the separate cells of which it is composed are more evident. Or, instead of this, the epithelium is much flattened so that the lumen of the tube is larger. I think that this flattening of the epithelium belongs to the kidneys which give urine containing a good deal of albumin.
The most constant and characteristic change is in the glomeruli. The capillaries which make up the glomerulus are dilated, with more or less thickening of their walls. So far as I know this change in
the glomeruli is constant and persists, even if the congestion is ceeded by a true nephritis.
While the congestion often persists up to the time of the patient's death, it may, instead of this, be followed by an acute or a chronic nephritis.
If there is an acute nephritis albumin is present in considerable quantities in the urine. After death the glomeruli, in addition to the dilatation of their capillaries, show an increase in the size and number of the cells which cover them. The epithelium of the con voluted tubes is flattened.
If there is a chronic nephritis the specific gravity of the urine falls and the excretion of urea is diminished. The nephritis follows the anatomical type of a chronic nephritis without exudation, but the dilatation of the capillaries of the glomeruli persists.