What is selective reabsorption?

Selective reabsorption occurs because during ultrafiltration, important components of the blood are filtered out and they need to be reabsorbed into the body. When the filtrate leaves the Bowman's capsule and enters the proximal convoluted tubule, sodium and chloride ions, as well as amino acids, glucose and vitamins move back into the blood. This occurs by them diffusing from the filtrate into the cells lining the proximal convoluted tubule. They are then actively transported out of these cells into the surrounding blood capillaries.