Reabsorption

  1. ALL Glucose and amino acids and some salt are reabsorbed from kidney tubules into capillaries by both diffusion and active transport.

  2. Reabsorption of glucose, amino acid cause the glomerulus filtrate more diluted and increase its water potential. The water potential of glomerulus filtrate is higher than that of the blood, there is net movement of water from proximal convoluted tubules into the capillaries by osmosis.

  3. Reabsorption of water from glomerular filtrate raises the concentration of urea in filtrate. The concentration of urea is higher in filtrate than that in blood, around urea is absorbed into the blood by diffusion.

  4. the amount of water reabsorbed is proportional to the amount of solutes reabsorbed. Hence, solute concentration remains the same as the fluid flow from at the beginning and the end of proximal convoluted tubules.