Originally appeared on the NOVA Web site Cut to the Heart ... Capillaries, on the other hand, are so small that it takes ten of them to equal the thickness of a human hair. Your body has about ...

The original design of the ring includes a heart held by two hands ... and how to wear it correctly—including which finger and hand to wear it on—keep on reading for the full scoop on the ...

But how much do you really know about your heart and how it ... Capillaries, on the other hand, are so small that it takes ten of them to equal the thickness of a human hair.