1220 



SPLANCHNOLOGY 



Fixation of the Kidney (Figs. 1125, 1126). The kidney and its vessels are im- 

 bedded in a mass of fatty tissue, termed the adipose capsule, which is thickest at 

 the margins of the kidney and is prolonged through the hilum into the renal sinus. 

 The kidney and the adipose capsule are enclosed in a sheath of fibrous tissue con- 

 tinuous with the subperitoneal fascia, and named the renal fascia. At the lateral 

 border of the kidney the renal fascia splits into an anterior and a posterior layer. 

 The anterior layer is carried medialward in front of the kidney and its vessels, 

 and is continuous over the aorta with the corresponding layer of the opposite 

 side. The posterior layer extends medialward behind the kidney and blends with 

 the fascia on the Quadratus lumborum and Psoas major, and through this fascia 

 is attached to the vertebral column. Above the suprarenal gland the two layers 

 of the renal fascia fuse, and unite with the fascia of the diaphragm ; below they 

 remain separate, and are gradually lost in the subperitoneal fascia of the iliac 

 fossa. The renal fascia is connected to the fibrous tunic of the kidney by numerous 

 trabeculse, which traverse the adipose capsule, and are strongest near the lower 

 end of the organ. Behind the fascia renalis is a considerable quantity of fat, which 

 constitutes the paranephric body. The kidney is held in position partly through 

 the attachment of the renal fascia and partly by the apposition of the neighboring 

 viscera. 



Subperitoneal fascia 



Anterior lamella of 

 renal fascia 



Peritoneum 

 Adipose capsule 



Paranephric "body 

 Quadratus lumborum 

 Sacrospinalis 

 FIG. 1126 Transverse section, showing the relations of the capsule of the kidney. (After Gerota.) 



General Structure of the Kidney. The kidney is invested by a fibrous tunic, 

 which forms a firm, smooth covering to the organ. The tunic can be easily stripped 

 off, but in doing so numerous fine processes of connective tissue and small bloodvessels 

 are torn through. Beneath this coat a thin, wide-meshed net-work of unstriped 

 muscular fiber forms an incomplete covering to the organ. When the capsule is 

 stripped off, the surface of the kidney is found to be smooth and even and of a deep 

 red color. In infants fissures extending for some depth may be seen on the surface 

 of the organ, a remnant of the lobular construction of the gland. The kidney is 

 dense in texture, but is easily lacerable by mechanical force. If a vertical section 



