Zobrazení příspěvků z prosinec, 2021
The Arctic fox lives in some of the most frigid extremes on the planet, but they do not start to shiver until the temperature drops to −70 °C.
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One way that Arctic foxes regulate their body temperature is by utilizing a countercurrent heat exchange in the blood of their legs.[14] Arctic foxes can constantly keep their feet above the tissue freezing point (−1 °C) when standing on cold substrates without losing mobility or feeling pain. They do this by increasing vasodilation and blood flow to a capillary rete in the pad surface, which is in direct contact with the snow rather than the entire foot. They selectively vasoconstrict blood vessels in the center of the foot pad, which conserves energy and minimizes heat loss.[16][31] Arctic foxes maintain the temperature in their paws independently from the core temperature. If the core temperature drops, the pad of the foot will remain constantly above the tissue freezing point.[31]
(https://en.wikipedia.org/wiki/Arctic_fox)