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quote:Originally posted by cuso4Now I got another theory.May be cells of penguins feet are surrounded with networks of cappilaries and this enables oxygen to be transported to the cells in the feet. So that energy can be generated by respiration to keep their feet warm.Angel
quote:Originally posted by NakedScientistANSWER TO : WHY DONíT PENGUINS FEET FREEZE ?Part of the reason is that penguins are birds and are warm blooded so they keep their feet from freezing by pumping warm blood from their body into them. But thatís only half the story because penguins live in such a cold environment that they would very quickly lose all of their body heat if they continuously pumped hot blood around their feet. Instead they have hit upon an ingenious solution which saves heat and keeps their feet just above freezing. In the penguinís legs the arteries, which carry hot blood from the body, are wrapped around the veins bringing cold blood back from the feet. The cold blood in the veins removes most of the heat from the arteries, warming up as it does so, so that the blood entering the feet is just above freezing, but the blood in the veins, by the time it reaches the body, is back up to body temperature. So the penguins feet receive blood just warm enough to keep them from freezing, but are not so hot that the penguin melts into the ice.
quote:Originally posted by NakedScientistHERE'S THIS WEEK'S "QUESTION OF THE WEEK" :"HOW, AND WHY, DO CHAMELEONS CHANGE COLOUR ?"Fire away.TNS