This is an excellent article by a company out of Israel that makes a device that actually measures the function of endothelial cells (cells that line the insides of our blood vessels).
For a great overview of these cells, what they do, and how they play a key role in cardiovascular disease, blood clotting, arteriosclerosis and atherosclerosis, go to
http://en.wikipedia.org/wiki/Endothelium
Wikipedia.org search for "endothelium."
You'll be glad you did!
