THE KIDNEYS. 



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posed of an aggregation of tubular glands inclosed in a 

 delicate, transparent, fibrous, investing structure, the 

 capsule of Bowman. The kidney presents for examination 

 an anterior and posterior surface, inner and outer border, 

 and a superior and inferior extremity. The anterior sur- 



FIG. 166. NAKED-EYE APPEARANCE OF THE KIDNEY. 



1, cortex ; 1'. medullary rays : 1", labyrinth ; 2, medulla; 2', papillary portion of the 

 medulla: 2", boundary layer of the medulla; 3, transverse section of tubules in boundary 

 layer ; 4, fat of renal sinus ; 5, artery ; *. transversely coursing medullary rays ; A, branch 

 of renal artery ; C, renal calyx ; U, ureter. 



face is convex and covered by peritoneum ; the posterior 

 surface is somewhat flattened. The outer border is 

 convex and rounded ; the inner border presents a notch 

 leading into a vertical fissure the hilum, which opens 

 into the sinus of the kidney. The superior extremity is 

 rounded and larger than the inferior ; upon the superior 



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