kidney 1: A longitudinal section, B nephron and adjacent blood vessels; 1 renal papilla, 2 renal column, 3 capsule, 4 renal pyramid, 5 calyx, 6 ureter, 7 renal pelvis, 8 renal vein, 9 renal artery, 10 interlobar artery, 11 arcuate artery, 12 interlobular artery, 13 interlobar vein, 14 cortex, 15 interlobular vein, 16 renal sinus, 17 arcuate vein, 18 medulla, 19 vasa recta, 20 loop of Henle, 21 collecting duct, 22 arcuate vein, 23 arcuate artery, 24 proximal convoluted tubule, 25 glomerulus, 26 Bowman's capsule, 27 distal convoluted tubule