THE KIDNEYS 445 



above, and opposite the third lumbar vertebra below. The 

 right kidney is lower than the left. In the female they are a 

 little lower than in the male. 



Each is bean-shaped, measures about 4 to 4 \ inches in length, 

 2j in breadth, and 1 to \\ inches in thickness, and weighs 

 about 4 to 6 ounces. They lie in the right and left hypochon- 

 drium, the epigastrium, and the right and left lumbar regions. 



The anterior surface of the kidney is convex and looks forward 

 and somewhat outward. 



The posterior surface is flatter than the anterior and is em- 

 bedded in fatty areolar tissue. 



The external border is convex, directed outward and back- 

 ward. 



The internal border is concave, directed forward and a little 

 downward, and presents a deep longitudinal fissure, the hilum, 

 for the passage of vessels and nerves. 



The superior extremity is directed upward and slightly inward, 

 is thick and rounded, supporting the suprarenal capsule. 



The inferior extremity is directed downward and slightly 

 outward. It is smaller and thinner than the upper, and extends 

 down to within about two inches of the iliac crest. 



The relations of the right kidney are in front, about three- 

 fourths of its surface rests in the impressio renalis of the inferior 

 surface of the right lobe of the liver; internally with the second 

 portion of the duodenum; the lower part is covered by the 

 ascending colon; the small intestines are also in relation. Behind 

 it rests on the psoas, the quadratus lumborum, the transversalis 

 muscles, the crus of the diaphragm, the anterior layer of the 

 lumbar aponeurosis, the internal and external arcuate liga- 

 ments, the lumbocostal ligaments, the last thoracic and first 

 lumbar nerves. The twelfth rib makes an impression in the 

 right kidney. Externally, its outer border rests on the abdom- 

 inal wall. Internally, the renal vessels and ureter, and the 

 inferior vena cava. Above, it is capped by the suprarenal 

 gland. Below, it extends to within 2 inches of the crest of 

 the ilium. The left kidney, in front, is covered along the upper 

 part by the suprarenal gland, the renal impression of the spleen 

 near its outer border, the body of the pancreas overlies its 

 middle area, and between the splenic and pancreatic relation 

 is a small space in contact with the posteroinferior surface 

 of the stomach, also the descending colon and the intestines 



