While everyone’s body constitutes the same elements, but then too we all vary from one another, the same is the matter of blood present in our body. There are mainly eight types of blood groups that are been inherited from the parents. The average amount of blood present in one’s body is around 4-6 liters.
Our blood is made up of different kinds of cells (RBC, WBC, Platelets) that are found in a fluid known as ‘plasma’.
ABO and Rh are the two significant to describe the type of blood group one is having, as the earlier one i.e. the ABO describes the blood type, while the second one i.e. the Rh or Rhesus factor describes the blood type as positive or negative.
ABO blood group system
In the ABO blood group system, there are four blood types and to know about each of them is important as they can be donated to others if they have the right match with the blood groups.
The antigens and antibodies present in the blood play a crucial role in determining the blood type. Antigens are the combinations of proteins and sugars that are present on the surface of the red blood cells (erythrocytes). While the plasma contains the antibodies that recognize the ‘foreign particle’ and further destroys them and so work efficiently in the body’s defence mechanism.
Therefore, depending on the combinations of the protein molecules i.e. antigens and antibodies present in one’s body make the basis of the blood type. Either you will have – no antigens, or A antigens, or B antigens, or both A and B antigens.
The Rhesus factor or Rh system determines the positive or negative blood. The D antigen present in this system plays the key role, as if the person has Rh D antigen, it implies that blood type to be positive while if the person lacks the Rh D antigen, it implies that person has the negative blood type.
How the ABO group and Rhesus system works
As we know that even the blood group is one of the inherited character, which is transferred by the parents to their children. So the ABO group provides the name of the blood type, while Rh gives the positive or negative type of blood group.
Blood group ‘O’: No antigens on red cells and anti-A and anti-B antibodies in plasma.
Blood group ‘A’: Antigen ‘A’ on the red blood cells and anti-B, antibodies in plasma.
Blood group ‘B’: Antigen ‘B’ on the red blood cells and anti-A, antibodies in plasma.
Blood group ‘AB’: Antigen ‘A’ and ‘B’ on red blood cells while no antibodies in plasma.
O positive blood group is the commonest among all the other blood group and A positive the second most common blood group. AB negative is the rarest case in the blood group system.
The person with the Rh-positive factor, but with another blood type can receive the blood from ‘O’ positive blood donor as they are known as the universal donors.
On the other hand, a person having the blood group as ‘AB’ positive can receive blood from any of the blood groups but having the Rh factor positive, and so these blood groups peoples are called as universal acceptor.