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Did you know?
When blood is exposed to air, it clots. Heparin allows the blood to come in direct contact with air without clotting.
Did you know?
There are 20 feet of blood vessels in each square inch of human skin.
Did you know?
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
Did you know?
There are more bacteria in your mouth than there are people in the world.
Did you know?
Not getting enough sleep can greatly weaken the immune system. Lack of sleep makes you more likely to catch a cold, or more difficult to fight off an infection.