Kidneys. 



59 



Pyramid?, 

 Ferret-nit 



396. Longitudinal Section through the Kidney. 



The renal artery enters the hilus dividing into four or five branches, which, 

 penetrating the substance of the organ, pass into the cortical substance between 

 the pyramids, and continue to divide and subdivide ; these branches have a con- 

 voluted arrangement and finally form the Glomeruli renales, which are surrounded 

 by a capsule. A vein smaller than the artery emerges from the glomerulus, and 

 divides into branches, from which a network of capillaries arises. The Tubuli uriniferi 

 commence at the capsule of the glomerulus opposite the place where the artery 

 enters and leaves; they are at first convoluted (Tubuli contorti I. ordinis), but 

 approaching the medullary portion become more or less spiral (spiral tubule 

 of Schachowa); they then enter the pyramids and form loops (looped 

 tubule of Henle, Ansae Henlei), pass back into the cortical substance to again 

 become convoluted (Tubuli contorti II. ordinis) and are connected with the 

 straight or collecting tubules. These straight tubules, Tubuli recti s. Belliniani, 

 enter the pyramids and are arranged in groups ; the tubes open at the papillae 

 by fine orifices, the Cribrum benedictum; the separate bundles of each tube form 

 the pyramids of Ferrein, these together form a Pyramis Malpighii (see 

 Fig. 399). The vascular loops in the pyramids come from the capillaries of the 

 cortical substance. 



The Calices renales minores receive the Papillae renales into their wide 

 mouths and unite (2 3) to form the Calices renales majores (infundibula) ; these 

 again, by their junction form the Pelvis renalis, which lies in the hilus behind the 

 renal artery and vein and becomes continuous with the ureter, which carries 

 the urine into the bladder. 



Q* 



