It's amazing to consider that just a 10-pint quantity of body liquid is so important for how our bodies function. Without blood, our organs couldn't get the oxygen and nutrients they need, we couldn't keep warm or cool off, we couldn't fight infections, and we couldn't get rid of our own waste products. If we lost too much blood, we'd weaken and even die. Put simply, we owe our lives to blood.

When we cut ourselves, we bleed. The blood we see is bright red, but the blood flowing through our veins is actually a darker, purplish color. Blood turns bright red after returning to our arteries from the lungs, where it picks up oxygen. Our pulse points "beat" where our arteries are near the skin. If we look closely, we can almost see our blood flowing, and each drop contains millions of functioning cells. An awesome consideration - when you stop to think about it - is that our blood never stops flowing, as long as we are alive.