430 CLINICAL APPLIED ANATOMY. 



be reached, without opening the peritoneum, from the lumbar 

 region, the iliac region, or the vagina. Calculi have also been 

 extracted from its lower end through the urinary bladder. 



In hydronephrosis and pyonephrosis the pelvis of the kidney 

 is dilated. This is due to some obstruction to the exit of urine 

 from it. Whether one or both kidneys suffer will depend upon 

 the site of the obstruction. If the impediment is in the urethra 

 or at the neck of the bladder both kidneys will be involved. 

 Pelvic lesions outside the bladder, near the trigone, may also 

 involve both ureters. The ureters run in the pelvic connective 

 tissue, towards the base of the bladder, coming into fairly close 

 contact with the cervix uteri. They may both be obstructed by 

 pelvic cellulitis, carcinoma of the cervix uteri, or uterine prolapse. 



Unilateral hydronephrosis may be due to obstruction of the 

 renal pelvis or of the ureter below this. It is particularly 

 associated with mobility of the kidney and is often intermittent 

 in such cases. An abnormal renal artery or vein may pass across 

 the upper part of the ureter and obstruct it, or the obstruction 

 may be due to an impacted calculus or pressure from without. 

 The relation of the first part of the pelvic colon to the left ureter 

 explains how the latter may become obstructed by a carcinoma in 

 this situation. The ureter as it passes into the pelvis follows the 

 course of the internal iliac artery and forms a posterior boundary 

 of the ovarian fossa ; consequently it is at times compressed by 

 malignant tumours of the ovary. 



Enlargements of the Kidney. The distinguishing charac- 

 teristics of renal enlargements are all based upon the anatomical 

 features and relations of the kidneys. 



The outline of a renal swelling is rounded and has no sharp 

 edges, conforming to the normal contour of a kidney; it may 

 thus be distinguished from enlargement of the spleen. 



The position of the colon with regard to the kidney is usually 

 maintained when the latter is enlarged. The presence of the 

 bowel in front of the swelling can sometimes be determined by 

 palpation and at others by percussion if the bowel happens to 

 contain gas, or has been artificially inflated from the rectum. 



