What exactly is your blood? It is billions and billions of cells floating in a liquid called plasma. Blood is like a river that flows to every part of your body through your arteries, veins, and capillaries.

The red cells in your blood are like delivery trucks. They bring oxygen from your lungs to all parts of your body tissue and take waste gas (carbon dioxide) from your tissues back to your lungs.

Your white cells are like warriors. They are always on guard to gobble up germs and anything that shouldn’t be in your blood and tissues.

Your blood contains platelets that join together to close cuts so you don’t bleed out. Platelets form tiny threads called fibrin, which trap red cells to form a clot or dam.

A single drop of blood contains about 5,000,000 red blood cells, 7,000 white blood cells, and thousands of platelets. 

Your blood is constantly being replaced. A red blood cell lives only about four months, and in that time, it makes about 300,000 trips through your bloodstream. About 10 million red blood cells wear out each second. Fortunately, new red cells are constantly replenishing in your blood. 

The approximately 25 trillion red cells in your blood would reach nearly halfway to the moon if lined up side-by-side.

You are indeed a mystery and a universe unto yourself.