io6 



HUMAN PHYSIOLOGY 



give off branches which radiate outward (b) and send branches 

 to each of the glomeruli (c). After giving off these branches, 

 the arterial trunk ends in capillaries in the outer part of the 

 cortex (</). 



Each glomerulus is formed by the afferent vessel (vas afferens) 



FIG. 7. DIAGRAM OF A URINARY TUBULE. 



dividing into a great number of loops. These loops then join 

 each other again, forming the vas efferens (i) which passes out of 

 the glomerulus and then splits up into capillaries. The capillary 

 net in the cortex surrounds the convoluted tubules (g). 



The arteriolae rectae () in the medullary portion are derived 

 partly from the vasa afferentia of the deepest glomeruli, partly 

 from the renal artery directly. These form straight capillaries in 

 the medulla, and at the papillae (m) form a ring-like capillary net- 

 work. The capillaries in the cortex empty into the veins radiating 



