31/07/2025
Do you know how urine is produced?
Urine is produced by your kidneys through a process that removes waste and excess substances from the blood. The production of urine happens in three main steps:
1. Filtration (in the glomerulus)
• Blood flows into a part of the kidney called the nephron, specifically into a structure called the glomerulus.
• The glomerulus filters out water, salts, glucose, amino acids, and waste products (like urea) from the blood into a structure called Bowman’s capsule.
• Large molecules like blood cells and proteins stay in the blood—they are too big to pass through the filter
2. Reabsorption (in the tubules)
• The filtered fluid (called filtrate) passes through the renal tubules.
• Useful substances like glucose, certain salts, and water are reabsorbed back into the bloodstream.
• This step ensures your body retains nutrients and only removes waste
3. Secretion (also in the tubules)
• Additional waste products and excess ions (like hydrogen and potassium) are actively secreted into the filtrate.
• This step fine-tunes the urine and helps balance your body’s pH and electrolyte levels.
Final Result: Urine
• What remains in the tubule becomes urine, which contains water, urea, salts, and other waste.
• The urine flows into the collecting ducts, then down the ureters to the bladder, where it’s stored until you urinate.