XXVIII.] 



KIDNEY, 



303 



Cortex. 



LESSON XXVIII. 



KIDNEY URETER BLADDER 

 KIDNEY. 



IF a kidney be divided longitudinally, one distinguishes a cortical 

 and a medullary part, the latter consisting in different animals of 

 one or more pyramidal 



6 



portions the pyramids 

 of Malpighi whose 

 apices project into the 

 pelvis of the kidney, 

 while their bases are 

 surrounded by cortical 

 substances. The medul- 

 lary portion is subdi- 

 vided into the boun- 

 dary or intermediate 

 zone and the papillary 

 portion (iig. 293). The 

 kidney is covered by a 

 loosely adherent cap- 

 sule. .It is a compound 

 tubular gland, consist- 

 ing of numerous urini- 

 ferous tubules closely 

 packed together with 

 very little connective 

 tissue between them, 

 the connective tissue 

 carrying the blood-ves- 

 sels, lymphatics, and 

 nerves. The urini - 

 ferous tubules pursue a 

 straight course in the 

 medulla, but they ex- 

 hibit a contorted or 

 convoluted arrangement 

 straight tubules the 



Boundary or 

 Omarginal 



zone. 



Fid. zy i. L.S. of n Pyramid of MalplgbL /'/'. Pyramids 

 of Kerrein ; HA. Branch of renal artery with an in- 

 terlobular artery; R\'. Lumen of a renal vein re- 

 ceiving an interlubular vein ; VR. Vasu recta; PA. 

 Apex of a renal papilla; l>b. Embrace the bases of 

 the lobules. 



in the cortex, although bundles of 

 medullary rays or pyramids of Ferrein 

 pass into the cortex from the medulla (fig. 293). Each uriniferous 



