TOPOGRAPHY OF THE THORAX AND ABDOMEN 59 



the right. Its outer border is much more convex than its 

 inner. The organ is located on the posterior abdominal 

 wall in the left lumbar region extending from the disc be- 

 tween the eleventh and twelfth thoracic vertebrae to the 

 disc between the second and third lumbar vertebrae. It 

 is less inclined than the right kidney, in both the frontal 

 and the sagittal plane. If its long axis were prolonged up- 

 ward it would cross the midplane in the region of the sixth 

 thoracic vertebra. The upper pole is about 4 cm. from the 

 midplane while the lower pole is only about 7 cm. from it. 

 The entire organ lies behind the midaxillary plane (Plates 

 XXXI and XXXV), and at a slightly higher level than the 

 right kidney (Plates XVI, XVII, XVIII and XXVIII to 

 XXXV). Posteriorly it lies over the eleventh rib, eleventh 

 intercostal space and the twelfth rib. It does not extend 

 below the tip of the twelfth rib more than about 1 cm., 

 while the right kidney extends nearly 4 cm. below the tip 

 of the right twelfth rib. When seen from the front more 

 than one-half of the left kidney is under cover of the costal 

 arch extending as far outward as the seventh costochon- 

 dral articulation. The posterior surface rests upon the dia- 

 phragm above and the psoas and quadratus muscles below. 

 The body of the pancreas crosses the anterior surface 

 of the kidney in the region of the hilus dividing it into 

 three areas. Above the pancreas the kidney is in relation 

 with the suprarenal, stomach and spleen, and below the 

 pancreas, with the colon and jejunoileum. The suprarenal 

 fits over the upper pole and medial border down to the 

 hilus. The lower part of the suprarenal separates a por- 

 tion of the kidney from the pancreas (Plate XVI). The 

 posterior part of this upper area and the lateral border are 

 attached to the spleen. The remainder of this upper area 

 is in relation with the stomach. It is small and bounded 



