Countercurrent

Complete separation can be achieved continuously by use of countercurrent exchange methods.

Internal adaptations The use of countercurrent heat exchange with blood flow allows for regulated conservation/ elimination of heat of appendages.

In these sharks, a strip of aerobic red muscle located near the center of the body generates the heat, which the body retains via a countercurrent exchange mechanism by a system of blood vessels called the rete mirabile ("miraculous net").

The pressed pulp is dried and sold as animal feed, while the liquid pressed out of the pulp is combined with the raw juice, or more often introduced into the diffuser at the appropriate point in the countercurrent process.

These countercurrent exchange methods extract more sugar from the cossettes using less water than if they merely sat in a hot water tank.

This allows for a countercurrent exchange system whereby the medulla becomes increasingly concentrated, but at the same time setting up an osmotic gradient for water to follow should the aquaporins of the collecting duct be opened by ADH.