THE KIDNEY 



439 



divisions of the kidney mid that, therefore, each of the suhdi visions 

 contains only certain characteristic portions of the renal tubule. Thu.- 



are found in the 

 CORTICAL LAHYRINT 

 (Pars Convoluta) 



CORTICAL RAYS .... 

 (Pars radial a} 



BOUNDARY ZONE OF 

 MEDULLA. 



M 



Kenal corpuscle. 

 Neck of the tubule. 

 Proximal convoluted portion. 

 Distal convoluted portion. 

 Arched colled ing portion. 



Spiral portion of the convoluted tubule. 

 Ascending limb of llenle's tubule. 

 Straight collecting portion. 



[Descending limb of Henle's tubule. 



THE 



Ascending limb of llenle's tubule. 

 [Straight collecting portion. 



Descending limb of llenle's tubule. 



PAPILLARY ZONE OF 

 MEDULLA . 



'I'll [: 



Loop of Henle's tubule. 

 Straight collecting portion. 

 Papillary duct. 



MEDULLA 



A. Outer Zone 



The following outline, based upon the investigations of Peter, gives a 

 more detailed classification of the different portions of the renal tubule 

 in the medulla : 



1. Outer stripe 



(a) straight collecting tubules. 



(b) proximal convoluted tubules. 



( c) thick ascending limbs of Henle's loops, 



including both 



(x) thick cloudy portions, and 

 (y) thick clear portions. 



2. Inner stripe 



(a) thin clear descending limbs of Henle's 



loops. 



(b) thick cloudy portion of ascending 



limbs of Henle's loops. 



(c) short loops of Henle, of thick cloudy 



type of epithelium. 

 B. Inner Zone 



(a) straight collecting tubules. 



(b) long loops of Henle, entirely of thin clear type of 



epithelium. 

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