Groups of human blood: what is the difference and why they cannot be mixed

If you stop on the street a passerby (although now it is not so easy to do) and ask what his blood type, he most likely will not be able to answer this question. Unless you were in the hospital, did not pass a technical analysis or do not have a good memory. But the knowledge of blood groups in an emergency can save a life: if in time to inform the doctor's blood, he will be able to find a suitable for transfusion. Moreover, some groups can be mixed together, while others strictly forbid it to do. What is blood and what determines the different transfusion groups?

the blood Group of a person

For a hundred years, one of the most important mysteries of our circulatory system remains without solution. We never found out why we are different blood groups. However, the fact that groups do exist, no doubt — the groups are set up by special molecules (antigens) on the surface of blood cells, they are "beads" that make up the blood.

The antigen define blood, and if the human body gets blood with a different type of antigens, it will be rejected. If the antigens are different, the body recognizes foreign red blood cells and begin to attack them. Therefore, when blood transfusion, it is important to consider group compatibility. But why the blood is divided into types? Wouldn't it be easier to have one universal group?

these «tablets» — red blood cells, is blood.

Of Course, it would be easier. But while scientists can't answer the question of why many people have different blood groups, create a universal group cannot. Last year scientists from the Medical College of national defence was tested in 10 rabbits. All animals were traumatized and suffered from severe blood loss. In the study of 10 survived, 6 rabbits received a transfusion of universal artificial blood. Survival among rabbits that received a transfusion of normal blood groups was exactly the same. The specialists noted that there are no side effects from the use of artificial blood was not detected. But that's not enough to talk about creating a "universal" blood.

So while working in the old way with different blood groups. How do they define it?

How to determine blood type

Current methods of identifying the blood group is far from perfect. They all involve the delivery of samples to the laboratory and takes at least 20 minutes, which can be very critical in certain conditions. Three years ago in China , is able to determine the group of your blood in just 30 seconds, even in field conditions, but it is not widely used in medicine because it has strong error.

For the determination of blood taken from a vein

Speed tests on the blood group is one of the main problems. Getting people in an accident, if it happened to them an accident – his blood will need to install in order to save his life. In case, if data on the victim no, have to wait another 20 minutes, and it provided that the laboratory is at hand.

Therefore, doctors strongly recommend or remember your blood (this test at least make in childhood, in hospitals and even on the draft Board in the army), or record it. Over on the iPhone where you can enter information about yourself, including your height, weight and blood group. In case you find yourself unconscious in the hospital.

Section «medical Records» the app «Health»

Today in the world 35 use of the systems of blood group. Most popular, including in Russia, received the ABO system. It the blood is divided into four groups: A, b, O and AB. In Russia, they for ease of use and memorizing numbers — I, II, III and IV. Between a blood group different content in plasma and erythrocytes of special proteins. These proteins are not always compatible, and if incompatible proteins connect, they can agglutinate red blood cells and destroy them. So there are rules of blood transfusion to transfuse blood only compatible with protein type.

For blood group it is mixed with reagent containing known antibodies. On the basis of applied three drops of blood: to the first add a drop of reagent anti-A, another drop of reagent anti-b, to the third reagent anti-D. the First two drops are used to define blood type, and the third — to identify the RH factor. If the red blood cells not stick together during the experience, so the group of human blood of the same type as an anti-reagent, which were added to it. For example, if in the drop, where the added reagent anti-A, particles of blood are separated, means that a person has blood group A (II).

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1 blood

First (I) the blood, it is group O. This is the most common blood group, she was diagnosed in 42% of the population. Its peculiarity is that on the surface of blood cells (erythrocytes) no antigen A or antigen B.

Because in group I no antigens, has long been considered that people with I blood group "universal donor" – they say that it will fit to any group, and "adapt" to the antigens in a new place. Now medicine has abandoned this concept, as there were cases, when organisms with a different blood group still rejected the I group. Therefore, transfusions are made almost exclusively of the "group in group", i.e. the donor (from whom transferred) must be the same blood group as that of the recipient (to whom it is transferred).

Man with I group of blood had previously considered «universal donor»

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2 blood group

Second (II) blood group, aka group A, means that on the surface of red blood cells is only antigen A. the extent of blood, it is at 37% of the population. If You have blood type A, then you cannot, for example, blood transfusion group (third group), because if your blood has antibodies that fight against antigens V.

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3 blood group

the Third (III) blood — group B, which is the opposite of the second group, since the blood cells are the only antigen B. It is present in 13% of people. Accordingly, if you transfuse someone with that group antigens of type A, they are rejected by the body.

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4 blood type

Fourth (IV) blood in the international classification is called group AB. This means that the blood contains as antigens A and B. antigens was Believed that if a person has such a group, he can receive blood of any group. Due to the presence of both antigens in group IV there is no blood protein that glues the red blood cells — this is the main feature of this group. Therefore, the red blood cells of the person doing the transfusion, do not push the fourth group of blood. And the carrier of blood group AB can be called a universal recipient. In fact, doctors rarely try to do this and only transfuse the same group blood.

In fact, for the fourth group there is nothing critical — the main thing is to transfuse blood of the same rhesus factor.

Visual distinction of blood groups

a Positive blood group

Belonging to the RH factor (Rh) is negative or positive. Depends on the status of the Rh antigen from another — D, which is on the surface of red blood cells. If the D antigen present on the surface of red blood cells, the status is considered RH positive, and if the D antigen is absent, the RH-negative.

If a person has a positive blood group (Rh+), and it is given negative, the red blood cells may stick together. The result is lumps that get stuck in blood vessels and disrupt blood flow, which can lead to death. Therefore, when blood transfusion is necessary with a precision of 100% know blood type and her RH factor.

Negative blood group

it is Important to determine the RH factor of blood

A Negative blood type (Rh-) indicates the absence of D antigen on the surface of red blood cells. If a person has the RH factor negative, in contact with RH-positive blood (e.g. blood transfusions), he can form antibodies.

The compatibility of the blood groups of donor and recipient is extremely important, because otherwise the recipient may be a dangerous reaction to a blood transfusion.

blood Group parents

If the blood cannot mix, then how to be in case of pregnancy? Doctors agree that no matter what group of the mother and father of the child, how much important their RH factor. If the RH factor mom and dad are different, during pregnancy there can be complications. For example, antibodies can cause problems during pregnancy in women with negative RH-factor, if she is carrying a child with a positive RH factor. Such patients are under special supervision from the doctors.

This does not mean that the child will be born sick — in the world there are many couples with different RH factors. Problems mainly occur only at conception and if the mother is RH negative.

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What blood group will the child

To date, scientists have developed methods with high accuracy to determine the blood group of a child, as well as its RH factor. You can find it visually by using the table below, where O — the first group of blood, A — the second, B — the third, AB — fourth.

the Dependence of blood group and RH factor of the child of blood group and rhesus parents

If one parent has IV blood group, children are born with differentblood groups

The Risk of conflict in the group the blood of the mother and the unborn child is very high, in some cases less, and in some impossible. the RH factor has no effect on the inheritance of a child of a particular blood group. By itself, the gene responsible for «+» RH factor is dominant. That is why with a negative RH factor from the mother, the risk of conflict on the RH is very high.

Can change blood type?

blood type remains unchanged: throughout a person's life. In theory, it might change the operation on the bone marrow, but only if the bone marrow of the patient is completely gone, and the donor — another group of blood. In practice no such cases, and the doctor will first try to operate on a man with the help of a donor organ that has the same blood group.

So I advise everyone to remember just in case my blood, especially since it does not change during life. And it is better to record and to inform relatives — in case of an emergency.

In the world recognized 4 groups of blood