sandgrubber Posted January 17, 2012 Share Posted January 17, 2012 By Ella Davies Reporter, BBC Nature 12 Jan, 2012 [/url]http://www.bbc.co.uk/nature/16426276 Dogs can keep warm on frozen ground, thanks to a specialised circulation system in their paws, say scientists. Researchers in Japan used electron microscopes to study the internal structure of domestic dogs' paws. They found that heat was transferred from the artery to the network of veins, meaning that cooled blood could not return to the body. The system has been recognised in many other animals' extremities, including penguins' beaks and dolphins' fins. The findings are published in the journal Veterinary Dermatology. Arctic foxes and wolves are well known for their adaptations that help them to regulate a constant body temperature in cold conditions. Continue reading the main story COLD-PROOF PAWS Arctic foxes have dense and rigid fur on their feet which keeps the pads away from the freezing ground The pads are connective tissue and fat which is more resistant to freezing They have a "rete mirabile" or "wonderful network" of veins in their feet and legs that works as a heat exchanger where cooled blood is warmed up to maintain a constant temperature (Additional research by Dr Arnaud Tarroux from the University of Quebec, Canada) Previous studies showed that the canines can keep the tissue in their feet from freezing even in temperatures of -35C. Dr Hiroyoshi Ninomiya and his team at the Yamazaki Gakuen University in Tokyo, Japan, set out to discover if this ability was also common to domestic dogs. Using electron microscopes, the researchers were able to examine the internal structure of dogs' paws. They found that the very close proximity of the arteries to the veins in the footpad meant that heat was conducted from one blood vessel to another. So when blood in the paw's veins cooled on contact with the air or ground, warm blood pumping from the heart - through the neighbouring artery - transferred its heat. The blood was therefore "warmed up" before it returned to the body - preventing the dog's body from cooling down, whilst also keeping the paws at a constant temperature. Link to comment Share on other sites More sharing options...
Erny Posted January 19, 2012 Share Posted January 19, 2012 Interesting piece of snippet, Sandgrubber. Ta for posting :). I like to know bits and pieces like this. Link to comment Share on other sites More sharing options...
Weasels Posted January 20, 2012 Share Posted January 20, 2012 I was trying to explain counter-current exchange in wolves to a fellow dog walker recently, but I had no idea if dogs had it too. Of course, DOL provides! Thanks Sandgrubber :) Link to comment Share on other sites More sharing options...
sandgrubber Posted January 21, 2012 Author Share Posted January 21, 2012 Wish we had more science news and less politics news :) Link to comment Share on other sites More sharing options...
Souff Posted January 21, 2012 Share Posted January 21, 2012 So much of the animal world is greatly underestimated and the ignorance of most of our society is mind blowing. Perhaps articles like this on the net can bring a greater education and appreciation. Thanks for that Sandgrubber. Souff Link to comment Share on other sites More sharing options...
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