What is the difference between filtrate and urine?
Filtrate is formed as soon as the water and its solutes leave the glomerular capillary and enter the Bowman's capsule. Filtrate contains everything that blood plasma does except blood proteins; but by the time filtrate has moved into the collecting ducts, it has lost most of its water, nutrients, and essential ions. When filtrate exits the collecting ducts into the calyces, it is called urine. What remains consists mostly of metabolic waste and unneeded substances.