Blood – inevitable for one’s survival. It cannot be synthesized artificially, hence its significance increases more. Blood inside our body is constantly metabolized (generated and degenerated). Body needs to maintain its blood level according to a person physiological status. Every single cell inside our body needs oxygen, which is delivered by blood. And so does it remove the metabolic waste(Co2) away from them. Any shortage in supply of oxygen the cell dies, a cascade of reactions occur. One of the possible reasons for insufficient blood is shortage of blood. Here again, one of the many reasons for blood shortage is blood loss. Blood loss can be due to increased destruction of blood, faulty blood clotting/coagulation and physical blood loss. Physical blood loss maybe due to accidents where enormous amount of blood is lost and body is unable to replace the loss by new cells. Thats the part where our advanced medical field comes into act. BLOOD TRANSFUSION.
Blood transfusion is a major area of study. One cannot just simply donate blood to everyone. Some basic knowledge about blood will help us to understand about blood and transfusion.
Blood consists basically of three components white blood cells, red blood cells and the plasma. Each of them have unique role to play. WBCs – Defense mechanism, RBCs – Exchange of gases and plasma – transport of molecules.
So why does a person have to know about his own blood group? what is it?
There are many blood system in our body, of them ABO system and Rh system is very significant. If the donor’s blood and receiver’s blood is not ABO and Rh compatible, blood clots and series of reactions which leads to death.
Blood grouping test
ABO System
RBCs in the blood contains specific antigen/s (protein) on its surface and that determines the blood group of a person. There are two antigens A and B. A person can A or B or both or neither of them, according to their blood groups.
Plasma of blood carries the antibodies (aprat from other molecules) which reacts with the antigen and thereby bringing about blood clumping/clotting. The antibodies (protein) are ANTI – A and ANTI – B. Antigen ‘A’ can react with antibody ‘ANTI – A’ and Antigen ‘B’ with antibody ‘ANTI – B’. Therefore a person with antigen A cannot have ANTI -A antibody in his plasma because they react with each other and blood clots. So the blood antigen combinations are like
Thus it explains clearly it is very dangerous to transfuse blood without knowing their blood group. Antigen and antibodies react with each other and it is fatal.
Blood group O universal donors? Yes, they do not have any antigen on RBC surface. Thereby no reaction with the antibody present in any other blood group.
Blood group AB Universal Receivers? Yes, they do not have antibodies in their plasma, hence they can receive blood from all the other blood group too.
Rh system(D)
It is the most important blood group sytem next to that of ABO system. Rh antigen present on the RBC surface makes the person Rh positive. He does not have any Rh antibody in the plasma. Rh negative persons do not have any Rh antigen on their RBC surface but have Rh antibodies in the plasma. Hence it is very important to check Rh compatibility before blood transfusion. Rh system plays a important role in pregnant ladies who are Rh negative carrying Rh positive babies, which may lead to hemolytic disease of the new born.
So, it is always good to know one’s own blood group. Even better to note that down in a piece of paper and kept along with our identity card which we carry all the time. Just in case of emergency, it will be very useful. However blood grouping tests are done for the donor and the recipient before blood transfusion.
