An animal standing in cold water or on ice benefits from countercurrent heat exchange (1). Warm arterial blood (2) flowing away from the heart warms up the cooler venous blood (3) heading toward ...

When we think of Antarctica, we imagine biting winds, icy landscapes, and sub-zero temperatures. Yet, penguins those charming ...

Their vascular system features a counter-current heat exchange mechanism: warm arterial blood flows close to veins carrying colder blood from the extremities.

In addition to maintaining higher core body temperatures than humans, birds have a unique circulatory system feature called ‘countercurrent heat exchange.’ As the blood circulates into the ...