MOVABLE KIDNEY. 423 



from the pelvic connective tissue, or from above the diaphragm, 

 and conversely the pus of a perinephritic abscess may extend 

 into the pelvic connective tissue, or invade the subpleural tissue, 

 and so the pleura and lung. It rarely bursts into the peritoneum, 

 but may open into the colon, or present in the lumbar region. 



Movable kidney may, or may not, be associated with general 

 prolapse of the abdominal viscera. The presence of a meso- 

 nephros as a cause of mobility is rare. More commonly the kidney 

 slips up and down behind the parietal peritoneum. Normally 

 the kidneys, being deeply situated in the loins, cannot be easily 

 palpated, save in very spare persons, but with care that the 

 abdominal muscles are well relaxed and bimanual palpation, the 

 difficulty may be got over. In the adult the right is three- 

 quarters of an inch lower than the left, but its lower pole 

 is above the level of the umbilicus, and an interval of an inch 

 and a quarter usually separates it from the iliac crest. (Fig. 53, 

 p. 419.) 



The factors which keep the kidney in position are its fascial 

 capsule, the attachments of the renal vessels, the pressure which 

 the abdominal muscles exert on it through the medium of the 

 abdominal viscera, and possibly also the reflections of peritoneum 

 on its anterior surface. The fatty capsule of the kidney is an 

 infiltration of the retroperitoneal tissue with fat, and the outer 

 layers of this capsule are condensed into a firm fibrous layer known 

 as the renal fascia. These layers fuse along the outer border 

 of the kidney and above, but do not closely unite below it. The 

 renal fascia is firmly attached to the crura of the diaphragm, to 

 the aorta, and the posterior abdominal wall. The same connective 

 tissue surrounds the renal vessels, forming with them a strong 

 pedicle. The pressure exerted by the muscles of the abdominal 

 walls has an important influence in keeping the kidney in place, 

 and the anterior surface of the organ when hardened in situ 

 shows two inclined planes which slope from the middle towards 

 each pole. These planes indicate the direction of the pressure 

 exerted by the super jacent viscera, the upper plane corresponding 

 to pressure exerted from above, and the lower to supporting 



