616 THE URINARY ORGANS. 



irregular blood-vessels. The united kidneys may be both situated on one side of the 

 vertebral column or in the pelvis. 



The foetal lobulation of the kidney frequently persists during adult life (Fig. 377). 



Changes in Position. 



The kidneys may be placed in an abnormal situation, in which they are either fixed 

 or movable. 



The change in position is either lateral or downward. When displaced downward 

 the kidney may be over the sacrum or below this in the cavity of the pelvis. The 



FIG. 377. FCETAL LOBULATION OF KIDNEYS ix ADULT. 

 The kidneys were of normal size. 



vessels also have an irregular origin and distribution. The kidney is firmly attached 

 in its abnormal position. 



Movable or wandering kidneys are found in adult life as a result of tight lacing, of 

 pregnancy, of overexertion, and of unknown causes. They are more common in 

 females than in males, and the right kidney is most frequently involved. The blood- 

 vessels become lengthened and the attachments of the kidney longer and looser. 



COMPENSATORY HYPERTROPHY OF THE KIDNEY. 



\Yhen one kidney is involved in lesions which seriously interfere with 

 its function the other organ may increase in functional capacity through 

 an hypertrophy and hyperplasia of its gland cells. A similar alteration 

 may take place in the sound parts of an organ partially compromised by 

 structural lesions. 1 



'For a study of this condition see Sacerdotti, Virchow's Arch., Bd. cxlvi., p. 267, 

 1896, bibliography. 



Consult also for general consideration of hypertrophy Thoma, "Text-Book of Gen- 

 eral Pathology," vol. i., p. 448, English translation. 



