afferent arteriole,nephron,glomerulus,collecting duct,kidney,efferent arteriole,facilitated diffusion,microvilli,lumen,bowmans capsule,basement membrane,pelvis,medulla,capillaries,bowman's capsule,co-transport,glomerular filtrate,concentration gradient,collecting ducts,ions,osmosis,pinocytic vesicles,amino acids,pinocytosis,selective reabsorption,sodium ions,proximal convoluted tubule,cortex,glomerular capillaries,loop of henle,ascending limb,renal artery,descending limb,renal vein,podocytes,ultrafiltration,distal convoluted tubule,peritubular capillaries,urea,tissue fluid,glucose,proteins,kidney stones,