Todays Interesting Facts

Today, I am studying up on the blood chapter of my book. Let me tell you something about erythrocytes (more commonly known as Red Blood Cells or RBCs). Normally, five Million cells are in a cubic millimeter of blood (a very tiny drop). A single erythrocyte contains 250 million hemoglobin molecules, each one capable of binding four molecules of oxygen. Thus, each red blood cell can carry one Billion molecules of oxygen... That just gives you something to think about... That one little drop of blood sure has a lot of oxygen molecules in it...