Glomerular Filtration Rate

The glomerular filtration rate (GFR) is the volume filtered by the glomerulus over time. In a healthy adult male about 180 litres of fluid are filtered by the glomerulus every day. This is enough fluid to fill up the petrol tank of two Rolls Royce motor cars.

Substances that are filtered in to the renal tubule include water, small proteins, salts (Na+, Cl-, K+, H+), glucose, nitrogenous waste products such as urea and other metabolic waste products and drug metabolites.