THE KIDNEYS. 425 



and second lumbar spines (H. J. Stiles). Viewed anteriorly, the lower edge of the 

 right kidney is 2.5 cm. (i in.) above a transverse line through the umbilicus, the 

 left being a little higher. The upper edge is opposite approximately the tip of the 

 ensiform cartilage. The upper end approaches within 3 cm. (i % in.) of the median 

 line. About two-thirds of the kidney lies to the inner side and one-third to the 

 outer of a line drawn longitudinally through the middle of Poupart's ligament. The 

 hilum would be 4 to 5 cm. ( i ^ to 2 in. ) out from the middle of a line joining the 

 upper extremities of the two semilunar lines. 



Deep Relations. The posterior surface at its upper portion rests on the 

 diaphragm; beneath, its lower portion, from within out, rests on the psoas, quadratus 

 lumborum, and transversalis muscles. Between the kidney and the quadratus lum- 

 borum run the last thoracic, the iliohypogastric, and the ilio-inguinal nerves. The 

 transversalis fascia as it leaves the body of the first lumbar vertebra arches over the 

 psoas muscle, forming the internal arcuate ligament, and is attached to the trans- 



Colon 



Quadratus lumborum 



Fio. 433. Posterior view, showing the relations of the spleen and kidneys. 



verse process of the first lumbar vertebra. It then proceeds out over the quadratus 

 lumborum to be attached to the outer portion of the twelfth rib, forming the external 

 arcuate ligament. It then blends with the tendon or fascia, giving origin to the 

 internal oblique and transversalis muscles. Between the fibres of the diaphragm 

 which arise from the external arcuate ligament over the quadratus lumborum 

 muscle and the fibres arising from the twelfth rib, a triangular space exists with its 

 base downward. It is called the hiatus and if marked allows the pleura and the 

 kidney to come in contact without any muscular fibres intervening. This favors the 

 passage of pus from the region of the kidney into the pleural cavity and lung. 



The anterior surface relations differ on the two sides. On the right side above 

 is the suprarenal gland, then a large area where it is in contact with the liver, then 

 below to the inner side the descending or second part of the duodenum, and below 

 and to the outer side the hepatic flexure of the colon. On the left side above and 

 to the inner side is the left suprarenal gland. Beneath it is a small area for the stom- 

 ach, and still lower a larger one for the left end of the pancreas. On the outer 



