THE KIDNEY 



1245 



flexure, but the remainder of the lower extremity and the whole of the upper one- 

 fourth of the organ is directly covered by peritoneum, the upper peritoneal area 

 having, as an indirect relation, the posterior surface of the stomach medially, 

 and the spleen laterally (figs. 956, 1009). 



The medial border of the right kidney approaches the vena cava inferior very 

 closely, especially above; that of the left is separated from the aorta by an inter- 

 val of about 2.5 cm. 



Fig. 1008. — Diagram of Relations of Posterior Surface of Left Kidney. 



Lower border of eleventh 

 and twelfth ribs 



Lateral border of quadratus 

 lumborum 



Area of pleural contact opposite 

 'hiatus diaphragmaticus' 



Medial lumbo-costal arch 

 Lateral lumbo-costal arch 



Variation in position. — The position of the kidneys in the abdominal cavity is subject 

 to considerable variation. Thus while the upper pole of the right kidney may be said to lie 

 typically opposite the lower half of the eleventh thoracic vertebra, it may be placed as high as 

 the lower part of the tenth thoracic or as low as the upper half of the first lumbar. Similarly 

 while the upper pole of the left kidney is as a rule opposite the middle of the eleventh thoracic 

 vertebra it may lie half a vertebra higher or as low as the lower part of the second lumbar 

 vertebra. The lower poles are distant from the crests of the iha anywhere from 1.0 cm.-3.0 



Fig. 1009. — Diagram showing Anterior Relations of Kidneys and Suprarenal Bodies. 



Duodenal area Hepatic area Gastric area 



(non-peritoneal) (non-peritoneal) Caval area (peritoneal) 



Hepatic area 

 (peritoneal) 



Duodenal area 

 (non-peritoneal) 



Colic area 

 (non-peritoneal) 



Pancreatic area 

 (non-peritoneal) 



Colic area 



(non-pentoneal) 



Peritoneal area wih right colic vessels 



Peritoneal area vnth left colic vessels 



cm., the distance being, as a rule, somewhat less in females than in males. Occasionally the 

 lower pole may even extend below the iliac crest, especially on the right side. 



The lateral border of each kidney lies 8.5-10.() cm. lateral to the spines of the lumbar 

 vertebrae, a distance that brings them lateral to the lateral edge of the sacro-spinalis muscle 

 and even to the lateral edge of the quadratus lumborum, so that this border may be readily 

 approached through the posterior wall of the body. It must be remembered, however, that 

 the upper part of the kidney rests upon the diaphragm, so that in the event of the twelfth rib 

 being very short there may be danger of the incision being carried too far upward, resulting in 

 injury to the diaphragm and pleura. It is also worthy of note that the diaphragmatic area of 



