Which human organ is primarily responsible for filtering nitrogenous wastes such as urea from the blood to form urine?

💡 Solution & Explanation

The kidneys are the primary excretory organs in humans containing millions of functional units called nephrons that filter blood, reabsorb vital nutrients, and excrete nitrogenous wastes as urine. The liver synthesizes urea from ammonia through the ornithine cycle, but elimination is handled by renal filtration. Dialysis is a medical procedure used when kidneys fail.