Selective reabsorption
The filtrate still holds much the body needs. As it flows along the tubule, the useful substances are taken back into the blood.
Selective reabsorption
Taking back into the blood, from the filtrate, only the substances the body needs is selective reabsorption.
- All the glucose and amino acids
- About 90% of the water, and more when the body is short of water
- The salts the body needs
About 120 cm3 of filtrate forms every minute, and about 95% of it is reabsorbed. Without reabsorption the body would lose its water within hours.