What is the Difference Between Filtration and Reabsorption?
The first stage in clearing blood is filtration. Filtration is the passage of liquid through a filter to remove the impurities. It occurs in the glomeruli. Blood pressure forces plasma, the liquid potion of the blood, through the capillary walls in the glomerulus. The plasma contains water, glucose, amino acids, and urea. Blood cells and proteins are too large to pass through the wall , so they stay in the blood. The fluid, which is now called filtrate, collects in the capsule and enters the renal tubule.