434 



PHYSIOLOGY. 



tissue processes and minute blood-vessels are torn which have served 

 as a means of attachment for the capsule. The denuded kidney pre- 

 sents a smooth, even surface of a deep-red color. 



For a proper naked-eye study of the kidney the organ must be 

 divided longitudinally from the hilus to its outer border, and the fat 

 and areolar tissue must be removed from the vessels and ureter. It 

 will at once be seen that the kidney is composed of a cavity, somewhat 



Fig. 162. Section of Kidney. (LANDOIS.) 



1, Cortex. 1', Medullary rays. 1", Labyrinth. 3, Medulla. 2', Papillary 

 portion of medulla. 2", Boundary layer of medulla. 4, Fat of renal sinus. 

 5, Artery. A, Branch of renal artery. U, Ureter. C, Renal calyx. 



centrally located, and the parenchyma of the organ, nearly surround- 

 ing the central cavity. This compartment, as before stated, is termed 

 the sinus, and is lined by a continuation of the fibrous covering of the 

 kidney. It is through the hilus that this fibrous covering passes, as 

 do the renal vessels and ureter. 



The ureter, upon entering the sinus, is expanded into a funnel- 

 shaped sac, the pelvis. The pelvis soon divides into several branches 



