The renal artery pushes blood into the kidney nonstop, and from there it fans out into tinier vessels until it hits millions of nephrons. Those nephrons are where the real sorting happens, pressure forces fluid into a filter that holds back blood cells and proteins while letting water, salts, nutrients, and waste through. Then the kidney starts reclaiming the good stuff: glucose, amino acids, and most of the water get reabsorbed into the bloodstream. It also tweaks salt and water levels on the fly to keep your internal balance steady. What’s left is concentrated urine that travels to the renal pelvis, down the ureter, and into the bladder for storage. Cleaned blood exits via the renal vein, ready to loop through the body again