vizeletképz

Vizeletképzés, also known as urine formation, is the process by which the kidneys filter blood and produce urine. This vital physiological function is carried out in three main stages: filtration, reabsorption, and secretion.

Filtration occurs in the glomerulus, a network of capillaries within the nephron. Blood pressure forces water and small solutes from the blood into Bowman's capsule, forming the glomerular filtrate. Larger molecules like proteins and blood cells remain in the blood.

Next, reabsorption takes place along the renal tubules. As the filtrate passes through the proximal convoluted tubule, the loop of Henle, and the distal convoluted tubule, essential substances such as glucose, amino acids, water, and ions are reabsorbed back into the bloodstream. This process is highly selective, ensuring that the body retains necessary nutrients.

Finally, secretion involves the active transport of certain waste products and excess ions from the blood into the renal tubules. This further refines the composition of the fluid, preparing it for excretion. Substances like urea, creatinine, and certain drugs are primarily removed through secretion.

The final product, urine, is then transported from the kidneys through the ureters to the bladder for storage and eventual elimination from the body via the urethra. This intricate process ensures the regulation of blood volume, blood pressure, electrolyte balance, and the removal of metabolic waste.