Henry Gray (18251861). Anatomy of the Human Body. 1918.
Fixation of the Kidney (Figs. 1125,1126).The kidney and its vessels are imbedded 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 continuous 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 trabeculæ, 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.
FIG. 1126 Transverse section, showing the relations of the capsule of the kidney. (After Gerota.) (See enlarged image)
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