488 



THE URINARY APPARATUS. 



The uriniferous tube has not everywhere the same direction or diameter 

 Taking it at its termination on the crest of the pelvis, and following it to its 



Fig. 249. 



SECTION OF THE CORTICAL SUBSTANCE OF THE KIDNEY 



A, A, Tubuli uriniferi divided transversely, showing the spheroidal epithelium in 

 their interior ; B, Malpighian capsule ; a, Its afferent branch of the renal artery ; 

 b y Its glomerulus of capillaries; c, c, Secreting plexus formed by its efferent 

 vessels ; d, d, Fibrous stroma. 



Fig. 250. 



DIAGRAM OP THE COURSE OF THE URINIFEROUS 

 TUBULE. 



a, Orifice of tubule at pelvic crest ; 6, Recurrent 

 branches which form loops, c, in the medullary 

 portion of the kidney, and terminate in the 

 Malpighian capsules in the cortical portion. 



origin in the Malpighian body, it 

 is found that the tubule is at first 

 single, straight, and voluminous, 

 but that during its course across 

 the medullary substance it divides 

 into three or four tubes, which, in 

 their turn, subdivide in a dicho- 

 tomous manner. These divisions 

 are less voluminous and straight, 

 and their diameter is uniform until 

 they reach the cortical substance; 

 here they bifurcate, each branch 

 becomes flexuous, and is designated 

 the uniting tube, and is continued 

 in a kind of elongated U shape, the 

 ansiform tube of Henle, which des- 

 cends towards the centre of the 

 kidney. The ascending branch of 

 this ansiform tube, whose diameter 

 is very small, suddenly dilates on 

 entering the cortical substance, 

 describes several bends, contracts 

 into a narrow neck, and then opens 

 into a Malpighian body, after having 

 taken the name of convoluted tube. 



The corpora Malpigniana (or 

 capsules) are minute vesicles, whose 

 walls possess the same structure as 

 the uriniferous tubes ; each lodges 

 a cluster of arterial capillaries or 

 renal glomerulus, and has two oppo- 

 site openings : one communicating 



