HISTOLOGY OF THE KIDNEYS. 



407 



richer vascular network in the cortex. The branches of 

 the renal vein have a similar course. 



The Minute Structure of the Kidney. The kidneys 

 are compound tubular glands, composed essentially of 



Fio. 115. Section through the right kidney from its outer to its inner b 

 1, cortex; 2, medulla; 2', pyramid of Malpighi; 2", pyramid of Ferrein; 5, 



border 

 , small 



branches of the renal artery entering between the'pyramids ; A, a branch of the 

 renal artery; C, the pelvis of the kidney; U, ureter; C, a calyx. 



branched microscopic uriniferous tubules, lined by epithe- 

 lium. Each tubule commences at a small opening on a 

 papilla and from thence has a very complex course to its 

 other extremity. Usually about twenty open, side by side, 

 on one papilla. There they have a diameter of about 



