Urine is formed by a process called glomerular filtration. This process is carried out in the kidneys and involves the filtering of blood plasma through the glomerulus. The glomerulus is a network of small blood vessels that filters out waste products and excess water, salts, and other substances from the plasma. Once filtered, the waste products and excess substances are collected in a network of tubules known as the renal tubules. As the tubules reabsorb needed substances, they produce a concentrated solution that is then collected in the bladder. This solution is the urine.
