Leeches

Leeches

The word leech is derived from the Old English word “laece,” or doctor, and Syrian physicians reportedly first used leeches for bleeding as early as 100 B.C. This was a painless and efficient way of drawing blood since the leech excretes several hormones including one to anesthetize the bite, one to dilate vessels to insure flow, and a third, hirudin, to act as an anticoagulant.