DISSECTION OF THE ABDOMEN. 



335 



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

 medullary vessels arise. 



The cortical or interlobular 

 arteries are larger and more 

 numerous than those for the 

 medvilla. They pass directly 

 outwards towards 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- 

 ulus, or capillary tuft. From 

 this again the blood is led out 

 of Bowman'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- 

 loTmlar veins, running alongside 



Fig. 43. 



the arteries. ihese mterlOOUlar vessels of the Kidneys, and ueinipeeoto Tdeules 



veins begin at the surface of the (modified from r«™«r). 



. , , , /.I- Papillary duct ; 2. Collecting tube ; 3. Inter- 



kldney by the convergence OI medlary tube ; 4. Looped tube of Henle ; 5. Con- 

 1 n ■ • ' n, voluted tube ; 6. Bowman's capsule ; A. Segment of 



a number or mmute veins irom artery forming renal arch ; B. Interlobular ai-tery 

 4.1,„ «„»,«,, 1,1 ^-.-..rvn'i-ir.. +Vio sf^llr.f^ C. Afferent TBssel of glomerulus; D. Efferent vessel 

 the capsule— forming the stellate ^^^^ ^^^.^ E. Glomerulus; F. Plexus formed by 



veins. The interlobular veins ;^* **''™**^ ^ ^- ^•■'^™''= ""=*** 5 h. interlobular 



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 arterioles rectce. These pass with 

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

 break up into a wide-meshed capillary network 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. 



