Kidney of a pigeon (HE): blood vessels
In the renal parenchyma, halfway between the intralobular and interlobular veins run the intralobular arteries (aa. intralobulares). After passing the glomeruli, the intralobular arteries together with the interlobular veins empty into a cortical peritubular capillary network (rete capillare peritubulare corticale), that ramifies between the cortical glomeruli and the convoluted tubules (tubuli convoluti) of the nephrons, thus forming portal-arterial anastomoses. Blood from the cortical capillary network drains into the central intralobular veins. The medullary capillary network (rete capillare glomerulare), as in mammals, is derived from the vasa rectae.