Blood groups are specific types of antigens on the surface of red blood cells in the human body, and they are divided according to specific genetic laws. Blood group classification is essential for medical operations such as blood transfusion and organ transplantation, so understanding the principle of blood group classification is of great significance for maintaining human health.
The classification of blood groups can be traced back to 1900, when Austrian scientist Carl Landsteiner discovered that human blood can be divided into three types: A, B, and C (later renamed O). This discovery laid the foundation for human blood typology. Later, scientists discovered AB blood group, and the ABO blood group system was perfected.
The division of the ABO blood group system is mainly based on two antigens on the surface of red blood cells: the A antigen and the B antigen. People with blood type A have a antigen on the surface of red blood cells and B antibodies in plasma; People with blood type B have B antigen on the surface of red blood cells and A antibodies in plasma; Human red blood cells with AB blood have both A and B antigens on the surface, and there are no A and B antibodies in plasma; People with blood type O have neither A antigen nor B antigen on the surface of red blood cells, and have A and B antibodies in plasma. The presence and absence of such antigens and antibodies determine the compatibility and mutual exclusion between different blood groups.
In addition to the ABO blood group system, there are various blood group systems such as the RH blood group system, MN blood group system, and P blood group system. Among them, the Rh blood group system is the most important. The Rh blood group system is divided into two types: Rh positive and Rh negative, of which the proportion of Rh negative blood type in the population is low, so it is called "panda blood". People with Rh-negative blood types need to be especially careful when transfusing blood because their plasma may contain anti-RH antibodies that attack Rh-positive red blood cells, causing hemolytic reactions.
The classification of blood groups is mainly based on the laws of heredity. Each person's blood type is inherited from their parents, half of which comes from their father and half from their mother. In the ABO blood group system, the A and B antigens are the dominant genes, while the O antigen is the recessive gene. Therefore, if a person's genotype is AA or AO, then his blood type is type A; If the genotype is BB or BO, then the blood type is B; If the genotype is AB, then the blood type is AB; If the genotype is Oo, then the blood type is O. The genetic pattern of the RH blood group system is similar, except that the genes and antigen types involved are different.
In conclusion, the classification of blood groups is based on the type of antigen on the surface of red blood cells and the laws of heredity. Understanding the principle of blood group classification is of great significance to human health, which can help us avoid unnecessary risks in medical procedures such as blood transfusion and organ transplantation. At the same time, with the continuous development of science and technology, people's research on blood group is also deepening, and more blood group systems may be discovered and applied in the future.