I cut my finger the other day and I started thinking what a miracle blood is.  Then I realized, I know very little about blood.  One thing is for sure, as an indicator of health, I think blood might be the one packed with the most information.  Every six months, they take three tubes of blood out of me, and I get a report a mile long about all the different measurements, and indicators of normal or abnormal readings. 

The average adult has about 10 pints of blood (roughly 8 percent of your body weight).  Blood cells are red, white, and platelets.   When you give blood, you lose red cells and the body needs to make more to replace them.  Special cells in the kidneys called peritubular cells, sense that the level of oxygen in the blood has decreased (due to the loss of the red cells) and starts secreting a protein called erythropoietin.  This passes through the blood stream to the bone marrow.   

The bone marrow produces stem cells, the building blocks to make the different cells in the blood.  Your body produces about 2 million new red cells every second, so it only takes a number of weeks to build up stores again.  

About 55 percent of blood is plasma, which is 90 percent water --  plasma being mostly water and salts absorbed through our digestive tracts each day.  Plasma is the transportation system of blood, and all the elements of blood are transported in it.  The majority of cells floating the plasma are red blood cells.  During the approximately four months they’re alive the red cells’s major role is transporting oxygen throughout your body.  The spleen continually destroys millions of old red blood cells, recycling the iron to make new red cells.   

 White blood cells help your body fight off infections.  They fight off germs, help with blood clotting, and destroy bacteria that shouldn’t be in your body.  Platelets help your body regulate the flow of bleeding, and begin the healing process at the source of a wound. 

So, let us give thanks to our bone marrow.  It is the miraculous stem cell factory that produces nearly all of our blood.  Hope you learned something; I know I certainly did.  

God bless you all -- RHM