How many blood groups are there? What does the blood group, compatibility, features

In the body of an adult person is continuously circulatingapproximately 5 liters of blood. From the heart it spreads through the body with a sufficiently branched vascular network. The heart needs about a minute, or 70 strokes, to skip all the blood that supplies all parts of the body with vital elements.

How does the circulatory system work?

It delivers oxygen-derived oxygen andNutrients are produced in the food tract where they are needed. Blood also transports hormones to the destination and stimulates the removal of decay products from the body. In the lungs it is enriched with oxygen, and carbon dioxide from it goes into the air when a person exhales. It carries the products of cell disintegration into the organs of excretion. In addition, blood takes care that the body always remains evenly warm. If a person has cold legs or hands, this means that he has insufficient blood supply.

Erythrocytes and leukocytes

These are cells with their own special qualities and "tasks." Red blood cells (erythrocytes) form in the bone marrow and are constantly updated. In 1 mm³ blood is 5 million red blood cells. Their task is to deliver oxygen to different cells of the whole body. White blood cells - leukocytes (6-8 thousand in 1 mm³). They oppress pathogens that have penetrated the body. When white corpuscles themselves are affected by the disease, the body loses protective functions, and a person can die even from a disease such as the flu, which with a normal system of protection quickly copes. White blood cells infected with AIDS are affected by the virus - the body can no longer resist disease itself. Each cell, leukocyte or erythrocyte is a living system, and on its vital activity all processes occurring in the body are displayed.

What does the blood group mean?

The composition of the blood differs in humans in the same way asappearance, hair and skin color. How many blood groups are there? There are four of them: O (I), A (II), B (III) and AB (IV). The fact that the group belongs to this or that blood is influenced by proteins contained in red blood cells and plasma.

Proteins-antigens in erythrocytes are called agglutinogens. Plasma proteins are called agglutinins. Agglutinogenes exist in two types: A and B, agglutinins are also subdivided - a and c.

That's what happens. Take 4 people, for example, Andrew, Alla, Alexei and Olga. Andrei has a blood group A with agglutinogens A in cells and agglutinins in plasma. Alla - group B: agglutinogens B and agglutinins a. Aleksei's group AB: features of the 4th blood group is that there are agglutinogens A and B in it, but there are absolutely no agglutinins. Olga has a group of O - she does not have agglutinogens at all, but agglutinins a and c are in the plasma. Each organism behaves with other agglutinogens as with a foreign aggressor.

Compatibility

If you pour Andrei with group A blood of group B,its agglutinins will not accept the alien substance. These cells can not move freely around the body. So, they can not deliver oxygen to such organs as the brain, and this is dangerous for life. The same will happen if you combine A and B groups. Substances B repel substances A, and for O (I) groups is not suitable for both A and B. To prevent errors before transfusion, patients are pre-tested for blood group. People who have blood group I are considered the best donors - it will suit anyone. How many blood groups exist - they all positively perceive the blood of group O, it does not contain in the red blood cells agglutinogens, which might not "like" the rest. Such people (as in our case Olga) are universal donors. Group AB contains both A- and B-proteins, it can be connected with the rest. Therefore, a patient with group 4 blood (AB), with the necessary transfusion, can safely receive any other. That's why people like Alexey got the name "universal consumers".

Nowadays, they try to transfuse a patientuse exactly the group of blood that is available to the patient, and only in emergency cases you can use the universal first. In any case, you must first check them for compatibility, so as not to harm the patient.

What is the Rh factor?

The red bodies of some people contain protein forcalled Rh factor, so they have a positive Rh factor. About those who do not have such protein, they say that they have a negative Rh factor, and they are allowed to transfuse only exactly the same blood. In the opposite case, their immune system will reject it after the first transfusion.

It is very important to determine the Rh factor in the periodpregnancy. If the mother has a second negative group and her father is positive, the child can inherit the Rh factor of the father. In this case, antibodies accumulate in the mother's blood, which can lead to the destruction of red blood cells. The second positive group of the fetus creates a Rh-conflict, dangerous for the life and health of the child.

Genetic Transmission Group

Just like a shade of hair, a person's bloodinherit from their parents. But this does not mean that the child will have the same composition as either or both of his parents. Sometimes this question is caused by family quarrels because of ignorance. In fact, the inheritance of blood is subject to certain laws of genetics. To understand what and how many blood groups there are in the formation of a new life, the table below will help.

For example, if a mother's blood is 4 groups, and her father's first, the child will not have the same blood as the mother. According to the table, he can have both the second and the third group.

Inheritance by a child of the blood group:

The Rh factor is also inherited. If, for example, both or one parent has a second positive group, the baby can be born with both positive and negative rhesus. If each parent has a negative Rhesus, the hereditary laws work. A child can have a first or second negative group.

Dependence on the origin of man

How many blood groups exist, what is theirthe ratio of different peoples, depends on the place of their origin. In the world, so many people undergo a blood group test that this has provided an opportunity for researchers to track how the frequency varies depending on geographical location. In the USA, 41% of Caucasians have blood of group A, compared with 27% of African Americans. Almost all Indians in Peru have I group, and in Central Asia the most common is the III group. Why these differences exist is not fully understood.

Exposure to certain diseases

But scientists noticed some interestingthe relationship between blood cells and certain diseases. Holders of the I blood group, for example, are more prone to the risk of an ulcer. And people who have a second group get a risk of getting stomach cancer. This is very strange, but the proteins that determine the composition of blood are very similar to proteins that are on the surface of certain pathogenic bacteria and viruses. If a person becomes infected with a virus with surface proteins similar to his own, the immune system can perceive them as his own and allow them to multiply unhindered.

For example, surface proteins of microorganisms,causing bubonic plague, are very similar to the proteins of the I blood group. Scientific researchers suspect that such people can be particularly prone to this infection. Scientists believe that the disease originated in southeast Asia and spread to the west. When it reached Europe, it destroyed one-fourth of its population in the XIV century: then the disease was called a "black death." In Central Asia, the smallest population with the first blood group lives. Therefore, it was this group that was the "drawback" in the areas where the plague was particularly rampant, and people with other groups had a better chance of survival. Scientists believe that the dependence of diseases on blood composition is observed. The study of this version will help in the future to decipher the genesis of ailments and reveal the secrets of the survival of mankind.