KIDNEY. 



a local thickening of the cell, but this is perhaps a post mortem appearance. 

 The descending limbs may suggest capillaries as seen in the is figures. 



The ascending limbs, 23-28 /j. in diameter, resemble the distal convo- 

 luted tubules said to measure from 39 to 44 ti. The cells in the distal 

 convoluted tubule are taller than in Henle's loop and they may have basal 



Capsule of the, 

 glomerulus. 



Glomerulus. 

 / 



Ascending limb 

 of Henle's 

 loop (?). 



Convoluted tubule. 



Capillary. 

 Descending limb of Henle's loop. 



Small collecting tubule. 



FIG. 287. FROM A SECTION THROUGH THE CORTEX OF A HUMAN KIDNEY (PARALLEL WITH THE 



SURFACE). 

 The pars radiata is seen in the lower left corner. X 200. (Schaper.) 



striations. Thus they are much like the proximal convoluted tubules 

 except that their markings are less distinct and their size is smaller. 



The collecting tubules are a distinct type, having a round, well defined 

 lumen and distinct cell walls. The round nuclei are arranged with striking 

 regularity. The cells are columnar in the papillary ducts which may 

 be 0.3 mm. in diameter. Although some cells of the collecting tubules 

 appear darker than others, they are thought to form only conducting tubes. 



