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When blood is exposed to air, it clots. Heparin allows the blood to come in direct contact with air without clotting.
The familiar sounds of your heart are made by the heart's valves as they open and close.
The average adult has about 21 square feet of skin.
In 1864, the first barbiturate (barbituric acid) was synthesized.
More than 30% of American adults, and about 12% of children utilize health care approaches that were developed outside of conventional medicine.
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