STEUCTUEE OF THE KIDNEY. 



197 



The following gives a tabular view of the parts which compose 

 a uriniferous tubule, and the nature of the epithelium in each 

 part : 



Blood-vessels. The renal artery divides into branches on entering 

 the organ, and these branches pass towards the cortex, forming in- 

 complete arches between the cortex and the medulla (fig. 233, a). 

 The branches of the renal vein form similar but more complete 

 arches (g). From the arterial arches vessels pass through the cortex 

 (interlobular arteries, &), and give off at intervals small arterioles 

 (efferent vessels of the glomeruli), each of which enters the dilated 

 commencement of a uriniferous tubule, within which it forms a 

 glomerulus. From the glomerulus a somewhat smaller efferent vessel 

 passes out, and this at once again breaks up into capillaries, which 

 are distributed amongst the tubules of the cortex (e) ; their blood is 

 collected by veins which accompany the arteries and join the venous 

 arches between the cortex and the medulla, receiving in their course 

 certain other veins which arise by radicles having a somewhat stellate 

 arrangement near the capsule (vence stellulce, j). 



The medulla derives its blood-supply from special offsets of the 



1 The part of the cortex between and surrounding the medullary rays is so named. 



