The stately giraffe, whose head sits some 16 feet up atop an unlikely pedestal, adapted his long neck to compete for foliage with other grazers. While the advantage of reach is obvious, some difficulties arise at such a height. The heart must pump twice as hard as a cow's to get blood up to the brain, and a complex blood vessel system is needed to ensure that blood doesn't rush to the head when bent over. Six feet below the heart, the skin of the legs must then be extremely tight to prevent blood from pooling at the hooves.
Thursday, May 27, 2010
Giraffes Compensate for Height with Unique Blood Flow
The stately giraffe, whose head sits some 16 feet up atop an unlikely pedestal, adapted his long neck to compete for foliage with other grazers. While the advantage of reach is obvious, some difficulties arise at such a height. The heart must pump twice as hard as a cow's to get blood up to the brain, and a complex blood vessel system is needed to ensure that blood doesn't rush to the head when bent over. Six feet below the heart, the skin of the legs must then be extremely tight to prevent blood from pooling at the hooves.
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