THE KIDNEY 443 



small venules, derived From (lie cortical capillaries and from occasional 

 anastomoses with the capsular vessels, unite to form broad thin-walled 

 venous spaces, the stellate veins of Ycrhcyn, just beneath tin- capsule. 

 From these subcapsular vessels the interlobular veins arise, and pass 

 toward the medulla in company with the interlobular arteries, throughout 

 their course collecting the minute venules which return the blood from 

 the capillaries about the tubules of the renal cortex. 



Arriving at the border of the medulla, but still embedded in the 

 cortical substance, the interlobular veins turn sharply, at nearly right 

 angles to their former course, and by free anastomoses form a venous 

 arcade (arciform vein), which receives the vennltr n'c/ir coming from the 

 capillary plexuses of the medulla, and at the border of the renal pyra- 

 mid enters a renal column to unite with similar vessels coming from the 

 borders of the adjacent pyramids. The union of these vessels forms 

 large venous trunks which leave the renal columns, in company with 

 the arteries, as the vena' i>roj>ri(e renales (interlobar veins). They enter 

 the connective tissue of the hi him, traverse the wall of the calyces, iu- 

 fundibula, and renal pelvis, and finally unite to form the renal vein. 



TABLE SHOWING THE COURSE OF THE RENAL CIRCULATION 

 Renal artery Renal vein 



Arteria? proprise renales Venae propriae renales 



I 



Arterial arcade Venous arcade 



/ \ 



Interlobular arteries Arteriolse rectae Venulse rectae Interlobular veins 



XX f \ 



Capillaries of medulla ' ' 



Afferent artery to renal corpuscle 



Vena- stellatir 



I - f 



I Capillaries of the cortical labyrinth 



Capillaries of the glomeruli T 



.\ I 



Efferent, vessel from renal corpuscle 



