/ Why is it necessary to know the designation of the blood group?

# Why is it necessary to know the designation of the blood group?

In the body of every living person there must be blood. And if in appearance, in physical and chemical composition, it is almost the same, there are still differences in it.

A bit of history

Human blood is divided into four groupsaccording to the type of antigens and 2 large groups with respect to a certain Rhesus factor. But doctors did not always know about this. Transfusion of her long time ago, doctors were trying to save people's lives. In some cases, they succeeded, but more often than not, such actions resulted in the death of the patient. What was the reason, they learned only in 1901 thanks to the Austrian doctor, who discovered certain differences between the samples taken. In some cases, the blood normally took root, and in others - the erythrocytes stuck together, which led to fatal consequences. It was this doctor who identified 4 blood groups and made the transfusion almost completely safe for health. For that in 1930 he was awarded the Nobel Prize.

What is the difference, and why is it different?designation of the blood group? It's all about the presence in the body of antigens - a kind of protein molecules, which determine it to a particular group. Antigens are located in the blood serum and on the surface of red blood cells. And they are responsible for a certain response of the immune system to transfused blood. Differences in blood groups consist in the presence or absence of antigens A and B in it, plus the presence of antibodies to the same antigens in the plasma.

Notation

What is the designation of the blood group? It is worth noting that in our country and in Europe the marks are somewhat different, but they are easy to decipher. At us it is accepted to distinguish groups simply on figures - the first, second, third and fourth. Foreigners also divide groups into antigens:

• 0 - the designation of the first blood group;
• A - the second blood group;
• В - the third group of blood;
• AB is the fourth blood group.

So what's the difference? So, in the first group (0) there are antibodies A and B exclusively in the blood plasma. In the second (A) - antigen A is located on the surface of all known red blood cells, and antibodies B exist in the blood plasma. In the third (B) - antibodies В "live" on the surface of erythrocytes (blood elements), and antibodies A - in the blood plasma; in the fourth antigens (both A and B) are on the surface of red blood cells - red blood cells.