DISSECTION OP THE ABDOMEN. 



335 



and anastomose to form a series of arches from wliich both cortical and 

 medullary vessels arise. 



The cortical or interlohtdar 

 arteries are larger and more 

 numerous than those for the 

 medulla. They pass directly 

 outwards towax-ds the surface of 

 the kidney, giving off lateral 

 branches — the vasa afferentia — to 

 Bowman's capsule, and terminal 

 branches to the fibrous coat of 

 the kidney. Each vas afferens 

 pierces Bowman's capsule, and 

 resolves itself into the glomer- 

 iihis, or capillary tuft. From 

 this again the blood is led out 

 of Bo^\^nan's capsule by the 

 vas efferens. The vasa efferentia 

 again resolve themselves into 

 capillaries, and these form a 

 network among the convoluted 

 tubes. From this intertubular 

 capillary network, small veins 

 arise and pass to join the inter- 

 lobular veins, ninning alongside 

 the arteries. These interlobular vj^gg^Ls of the kidxeys 

 veins begin at the surface of the 

 kidney by the convergence of _ . . 



, /> • X • c voluted tube ;' 0. Bowman's capsule ; A. Segment of 



a number of mmute vemS from artery forming renal arch ; B. Interlobular artery 



+l->o ^Qnoiilo fnvniincr fViP <ifel1ntp C. Afferent vessel of glomerulus; D. Efferent vessel 



tne capsule— 101 mmg tne SteUate ^^ the same; B. Glomerulus; F. Plexus formed by 



veins. The interlobular veins ^^^ ^^^^«°*'''^ 5 ^- ^^'^^^''^ '"<='**! 2- ^"^^'■i°^"'^'^ 



join venous arches disposed in 



the boundary layer between cortex and medulla, and from these arise 



the larger branches that finally unite to form the large renal vein at the 



hilus. 



The medulla is less vascular than the cortex. Springing from the 

 arterial arches in the boundary layer are branches that break up into 

 pencils of long straight arterioles — the arteriolce rectce. These pass with 

 a rectilinear course between the straight tubules of the medulla, and 

 break up into a wide-meshed capillary netv.-ork around and between these 

 tubules. Veins having a straight course like the arteries run in 

 company with them, and join the venous arches in the boundary layer. 



Connective-tissue of the Kidney. — This exists very sparingly between 

 the tubes in the cortex, but more abundantly in the medulla. 



Fig. 4.3. 



. and uriniferous tubules 

 (motUfled from Turner). 

 1. Papillary duct ; 2. Collecting tube ; 3. Inter- 

 mediary tube ; 4. Looped tube of Henle ; 5. Con- 



