Countercurrent heat exchange is a biological system in organisms in which two parallel pipes of flowing fluid work together to save energy. In the tongue of the blue whale, parallel vessels flow in and out of the body to help warm the blood returning from the tip of the tongue. The system is also present in the extremities of other cold-weather mammals and birds.Continue Reading
Without a system of countercurrent heat exchange, the blue whale would not be able to take in the amount of cold water needed to feed itself sufficiently. Also, the heat transported by the arteries to the tip of the tongue would not be employed as effectively. As it is, veins with blood cooled by the water run parallel to the arteries in the whale's tongue, and the blood is efficiently warmed before it returns to the body. The flippers of the dolphin and the blue whale employ the same countercurrent heat exchange system.
Parallel pipes running in the same direction, such as two veins or two arteries, are called concurrent. This system is not as efficient as countercurrent heat exchange systems in warming up the blood before it returns to the body from an extremity or other exposed part.Learn more about Thermodynamics