科学60秒:强大的人类竟不如小小鸟
[ 1 ] . But sometimes what makes you stronger can kill you, at least when it comes to blood clotting. [ 2 ] .
[ 3 ] But birds don’t have ‘em, nor do reptiles or fish. Instead, these critters have blood cells called thrombocytes, which are about twice the size of platelets. But is bigger necessarily better when it comes to clotting? Scientists took thrombocytes from parakeets and put them to the test. The work appears in the journal Blood. [Alec A. Schmaier et al., "Occlusive thrombi arise in mammals but not birds in response to arterial injury: evolutionary insight into human cardiovascular disease"]
[ 4 ] , in that blood exerts pressure on walls of blood vessels.
The results: parakeet thrombocytes don’t stick together like platelets do. [ 5 ]
Which means that mice may be more likely to survive a bloodletting-pecking. But birds are far less likely to suffer from the clot forming economy class syndrome—despite being frequent fliers.
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