VI 

 THE GENITO-URINARY SYSTEM 



THE KIDNEYS 



THE Kidneys are situated, for the most part, in the 

 epigastric and hypochondriac regions (p. 234), but their lower 

 poles extend for a short distance below the subcostal plane. 

 On account of the great bulk of the right lobe of the liver, the 

 right kidney lies at a somewhat lower level than the left 

 kidney, but this difference in position is subject to considerable 

 variation. 



As a general rule, the transpyloric plane passes through 

 the hilum of the right kidney a little above its middle, 

 whereas it cuts the hilum of the left kidney a little below 

 its middle. 



The long axes of the kidneys are placed obliquely, so that 

 the upper pole of the organ, which is almost entirely under 

 cover of the costal margin, is nearer to the median plane than 

 the lower pole, which projects downwards beyond the level of 

 the costal margin (Fig. 124). In length the kidney measures 

 about 4^ inches, and it is about 2\ inches wide. The hilum 

 lies i J to 2 inches from the median plane. 



When the position of the transpyloric plane has been 

 determined, the information given above is sufficient to enable 

 the outline of the kidney to be mapped out on the surface of 

 the body. 



Relations, i. Anteriorly. Both kidneys are retro-peri- 

 toneal and, therefore, their normal range of movement is exceed- 



357 



