- How do kidneys work?
- Rich blood supply
- Filter blood, reabsorb everything body needs
- Glucose, amino acids, mineral ions, urea, H2O move out of blood into kidney tubules, move by diffusion against conc gradient
- Blood cells and proteins are lg left behind - too big to pass through membrane of tubule
- Sugar reabsorbed by active transport
- Selective reabsorption(depends on what is needed by body)
- Urine is yellow due to yellow pigments UROBILINS that come from breakdown of haemoglobin in liver