SECTION IL 



DISEASES OF THE PELVIS OF THE KIDNEYS 

 AND URETERS. 



CHAPTER I. 



DILATATION OP THE PELVIS OF THE KIDNEY, WITH ATROPHY OF THE 

 RENAL SUBSTANCE HYDRONEPHROSIS. 



ETIOLOGY. Whenever the flow of the urine, through the ureters, 

 into the bladder, becomes permanently obstructed, the urine accumu- 

 lates in the pelvis and calyces of the kidney. If the pressure of the 

 urine within the pelvis of the kidney be very great, the openings in 

 the tubuli recti and papillae are closed, and the papillae themselves be- 

 come compressed. The urine then ceases to flow from the kidney into 

 it* pelvis, and distention of the latter would progress no farther were 

 it not that the pelvis and calyces possess a mucous membrane, and still 

 continue to produce mucus, which is mingled with the accumulated 

 urine. Hence more and more liquid collects in the renal pelvis, dis- 

 tending the latter, till finally the pressure flattens out the papillae, and 

 induces a gradual atrophy, which may terminate in the total loss of the 

 STibstance of the organ. 



Closure of the ureter may proceed from the impaction into it of a 

 stone. Far more frequently, hydronephrosis depends upon compres- 

 sion of the ureter by a tumor, or by a callous contracting cicatrix in 

 the peritonaeum which covers it, or by a growth, especially by a cancer, 

 of the subperitoneal connective tissue. In other cases, closure of the 

 ureter is the result of inflammation, which has induced swelling of its 

 mucous membrane, or adhesion of its walls. The lower and the closer 

 to the bladder the obstruction is, so much the larger is the portion of 

 ureter which takes part in the dilatation. 



Moderate degrees of dilatation of the uriniferous apparatus some- 

 times arise from an impediment to the discharge of urine, which exists 



