Filtration Process
Kidneys filter blood through millions of tiny filtering units called nephrons. Each nephron contains a glomerulus, where blood pressure forces water, salts, and waste products through tiny blood vessel walls. This initial filtration process handles about 180 liters of fluid daily, though most is reabsorbed. The system precisely controls what leaves the blood and what returns, maintaining proper blood composition.
Reabsorption Mechanisms
After initial filtration, the kidney tubules selectively reabsorb essential substances including water, glucose, and minerals. This process responds to body needs, adjusting reabsorption rates to maintain proper blood concentrations. Hormones regulate this process, increasing or decreasing water retention based on body hydration levels. The system can concentrate or dilute urine as needed to maintain fluid balance.
Waste Elimination
The kidneys remove waste products including urea from protein breakdown and excess minerals from blood. They help regulate blood pH by controlling acid-base balance and maintain proper electrolyte levels. The organs also produce hormones that stimulate red blood cell production and help regulate blood pressure. This complex system ensures stable internal conditions while removing harmful waste products. Shutdown123