380 



ABDOMEN 



Posterior Surfaces of the Kidneys. The posterior surface 

 of each kidney is mapped out into a medial and a lateral 

 district. The medial district is the narrower of the two, and 

 looks medially and backwards. It is in apposition with the 

 psoas major muscle and the crus of the diaphragm, and it is 

 separated from the lateral district by a rounded ridge, which 

 corresponds to the angle between the planes of the psoas 

 and quadratus lumborum muscles. The lateral district looks 

 backwards. In its upper third it rests on the diaphragm, 

 and in its lower two-thirds, upon the quadratus lumborum 



Splenic artery 



Colon 



Suprarenal 

 gland 



Crus of. 

 diaphragm 



Spleen 

 Left kidney 



FIG. 179. Transverse section through Abdomen at the level of the first 

 lumbar vertebra. 



1. Pancreas. 



2. Splenic vein, joining the portal 



vein. 



3. Aorta, giving off the superior 



mesenteric artery. 



4. Rod in bile-duct. 



5. Inferior vena cava. 



and the aponeurosis of origin of the transversus muscle. 

 The upper end of the kidney curves slightly forwards in 

 correspondence with the diaphragm, on which it lies; and 

 it should be borne in mind that between the diaphragm and 

 the last rib the pleural cavity descends behind the kidney 

 for a short distance (Fig. 180). 



Additional posterior relations are: the lumbo-costal arches; 

 the last thoracic nerve and the sub-costal artery; and, at a 

 lower level, the ilio-hypogastric nerve. The ilio-inguinal 

 nerve may also be a posterior relation, but in many cases it 

 lies below the level of the lower pole of the kidney. 



In spare subjects, when the kidneys have been hardened 



