ENLAEGEMENT OF THE KIDNEY. 431 



The hepatic flexure of the colon lies in front and to the inner 

 side of the lower end of the right kidney, whilst the splenic 

 flexure lies in front and to the outer side of the left, coming into 

 relation with it nearer the level of the hilus so that a consider- 

 able length of descending colon passes down in front of it. This 

 difference in the relation of the colon to the kidney on the two 

 sides accounts for the fact that colic resonance is more often 

 demonstrable over a left than a right renal swelling. Bowel 

 never passes between the spleen and the parietes, the colon lying 

 on the inner aspect of this viscus, and only under exceptional 

 circumstances does large or small intestine override the liver. 



The kidneys lie closely applied to the spinal column on each 

 side and no area of resonance can be demonstrated between a 

 renal tumour and the spine, whereas theoretically it should be 

 possible to elicit a triangular area of pulmonary resonance, with 

 the apex downwards, between the vertebral end of a large spleen 

 and the spinal column. The thick muscular mass at the side of 

 the spinal column renders this sign, however, of but little use. 



The close proximity of the kidneys to the spine also explains 

 the fact that there is no appreciable interval between a renal 

 swelling and the vertebrae of the lumbar region. 



The directions in which an enlarged kidney is seen to project 

 are also determined by its surroundings. It cannot project 

 backwards because the bed on which the kidney rests consists of 

 the psoas, the quadratus lumborum and the diaphragm, and to 

 the resistance offered by these muscles is added the support 

 of the lumbar transverse processes, the last rib and the arcuate 

 ligaments. Extension of the tumour directly inwards is resisted 

 by the prominence of the vertebral bodies, whilst extension 

 upwards is prevented by the action of the diaphragm. The 

 kidney as a result tends to enlarge forwards and outwards, pro- 

 jecting forwards at or near the level of the umbilicus below the 

 position of the liver or stomach, and also extending towards the 

 flank. Although a renal enlargement, except in certain cases of 

 infiltrating malignant disease or of perinephritic suppuration, 

 does not bulge backwards, yet it can be felt to "fill the loin" 



