If a person loses a large amount of blood, the constancy of the volume of the internal environment of the body is violated. And therefore, since ancient times, in the case of blood loss, in case of diseases, people tried to transfuse the sick blood of animals or a healthy person.
Written monuments of the ancient Egyptians, the writings of the Greek scientist and philosopher Pythagoras, in the works of the Greek poet Homer and the Roman poet Ovid describe attempts to use blood for healing. Patients were allowed to drink the blood of animals or healthy people. Naturally, this did not bring success.
In 1667, in France, J. Denis produced the first intravenous blood transfusion in the history of mankind to humans. The bloodless dying youth was transferred to the blood of a lamb. Although alien blood caused a severe reaction, the patient suffered it and recovered. Success inspired doctors. However, subsequent attempts at blood transfusions were unsuccessful. Relatives of the victims filed a lawsuit against the doctors, and blood transfusions were prohibited by law.
At the end of the XVIII century. It was proved that the failures and serious complications that occurred during the transfusion of animals with human blood are due to the fact that the erythrocytes of an animal stick together and are destroyed in the human bloodstream. At the same time, substances that act on the human body as poisons are released from them. Began to try to transfuse human blood.
Fig. 10. Glued red blood cells under a microscope (in a circle)
The first in the world blood transfusion from person to person was done in 1819 in England. In Russia it was produced for the first time in 1832 by the St. Petersburg physician Wolf. The success of this transfusion was brilliant: the life of a woman who was dying due to a lot of blood loss was saved. And then everything went the same way: either a brilliant success, a serious complication, even death. Complications are very similar to the effect that was observed after the transfusion of animal blood to humans. Hence, in some cases, the blood of one person may be alien to another.
A scientific answer to this question was given almost simultaneously by two scientists – Austrian Karl Landsteiner and Czech Jan Yansky. They found in people 4 blood groups.
Landsteiner drew attention to the fact that sometimes the blood serum of one person sticks together the erythrocytes of the blood of another (Fig. 10). This phenomenon is called agglutination. The property of erythrocytes to stick together under the action of the plasma or serum of another person on them became the basis for the separation of the blood of all people into 4 groups (Table 4).
Table 4. Blood groups
Why does gluing, or agglutination, of erythrocytes occur?
In the erythrocytes substances of protein nature were found, which were called agglutinogens (bonded substances). People have two kinds of them. Conventionally, they are designated by the letters of the Latin alphabet – A and B.
People with I blood group have no agglutinogens in erythrocytes, blood of group II contains agglutinogen A, in erythrocytes of blood of group III there is an agglutinogen B, blood of group IV contains agglutinogens A and B.
Due to the fact that there are no agglutinogens in the erythrocytes of the I blood group, this group is designated as the zero (0) group. Group II due to the presence of agglutinogen A in erythrocytes is designated A, group III – B, group IV – AB.
Found in blood plasma agglutinins (adhesive substances) of two kinds. They are designated by letters of the Greek alphabet – α (alpha) and β (beta).
Agglutinin α glues erythrocytes with agglutinogen A, agglutinin β glues erythrocytes with agglutinogen B.
In the serum of the I (0) group there are α and β agglutinins, in the blood of the II (A) group – agglutinin β, in the blood of the III (B) group – agglutinin α, in the blood of the IV (AB) agglutinin group there.
It is possible to determine the blood group if you have ready serums of the II and III groups.
The principle of blood grouping is as follows. Within one blood group there is no agglutination (gluing) of erythrocytes. However, agglutination can occur, and red blood cells will clump together if they fall into the plasma or serum of another group. Therefore, combining the blood of the test with a known (standard) serum, it is possible by the agglutination reaction to solve the issue of group membership of the blood to be tested. Standard serum in ampoules can be obtained at the station (or in points) of blood transfusion.
On a glass slide with a stick, apply a drop of serum II and III blood groups. To avoid mistakes, put the appropriate number of serum group on the glass near each drop. Use a needle to pierce the skin of your finger and, using a glass rod, transfer a drop of test blood into a drop of standard serum; Stir the blood thoroughly in a drop of whey with a stick until the mixture is evenly pink. After 2 minutes, add 1-2 drops of saline to each of the drops and mix again. Ensure that a clean glass rod is used for each manipulation. Place a glass slide on white paper and after 5 minutes review the results. In the absence of agglutination, a drop is a uniform turbid suspension of erythrocytes. In the case of agglutination with the simple eye, the formation of erythrocyte flakes in a clear liquid is seen. In this case, there are 4 options that allow to refer the test blood to one of four groups. Figure 11 can help you in resolving this issue.
Fig. 11. Determination of blood groups (the groups to which the sera belong, are marked with Roman numerals): 1 – agglutination did not occur in serum of either II or III group – blood of group I, 2 – agglutination occurred in serum of group III – blood of group II: 3 – agglutination occurred in serum of group II – blood of group III; 4 – agglutination occurred in serum of groups II and III – group IV blood
If the agglutination is absent in all the drops, this indicates that the blood of the test group belongs to group I. If the agglutination is absent in the serum of the III (B) group and occurred in the serum of the II (A) group, then the test blood belongs to the III group. If agglutination is absent in serum group II and is present in serum group III, then the blood belongs to group II. When agglutinated with both sera, it is possible to speak of belonging to the blood of the IV (AB) group.
It should be remembered that the agglutination reaction strongly depends on the temperature. It does not occur in the cold, and at high temperatures, erythrocyte agglutination can also occur with non-specific serum. It is best to work at a temperature of 18-22 ° C.
I group blood on average have 40% of people, group II – 39%, III- 15%, group IV – 6%.
The blood of all four groups is equally high in quality and differs only in the described properties.
Belonging to one or another blood group does not depend on race or nationality. Blood type does not change during the life of a person.
Under normal conditions in the blood of the same person, agglutinogens and agglutinins of the same name cannot occur (A cannot meet with α, B cannot meet with β). This can only happen with improper blood transfusions. Then the agglutination reaction occurs, the erythrocytes are glued together. Lumps of glued red blood cells can clog the capillaries, which is very dangerous for humans. Following the gluing of red blood cells, their destruction begins. Poisonous decomposition products of red blood cells poison the body. This explains the serious complications and even death due to improperly performed blood transfusion.
Blood transfusion rules
The study of blood groups allowed to establish the rules of blood transfusion.
People who give blood are called by donors, and people who pour blood – by recipients.
When transfusing, it is imperative to consider the compatibility of blood groups. It is important that as a result of blood transfusion, the red blood cells of the donor do not stick together with the blood of the recipient (Table 5).
Table 5. Compatibility of blood groups
In Table 5, agglutination is indicated by a plus sign (+), and the absence of agglutination is indicated by a minus sign (-).
The blood of people of the I group can be transfused to all people, therefore people with I blood group are called universal donors. The blood of people of the II group can be transfused to people with the II and IV blood groups, the blood of people of the III group – to people with the III and IV blood groups.
From table 5 it is also seen (see horizontally) that if the recipient has a blood group I, then he can only receive blood I group, in all other cases agglutination will occur. People with IV blood group are called universal recipients, since they can receive blood from all four groups, but their blood can only be given to people with IV blood (Fig. 12).
During blood transfusion, even with careful consideration of the group affiliation of the donor and recipient, sometimes there were serious complications. It turned out that in erythrocytes 85% of people have a so-called rhesus factor. So it is named because it was first discovered in the blood of the monkey Macacus rhesus. Rh factor – protein. People whose red blood cells contain this protein are called rhesus positive. In the erythrocytes of blood 15% of people are not Rh factor, this is rhesus negative people.
Fig. 12. Scheme of blood group compatibility. The arrows indicate which blood groups can be transfused to persons with a particular blood group.
Unlike agglutinogens, ready-made antibodies (agglutinins) are not available for Rh factor in human blood plasma. But antibodies against the Rh factor can be formed. If blood Rh-negative people transfuse blood Rh-positive, then the destruction of red blood cells during the first transfusion will not occur, because the recipient’s blood does not have ready antibodies to the Rh factor. But after the first transfusion, they are formed, since the Rh factor is an alien protein for the blood of the Rh-negative person. With repeated transfusions of Rh-positive blood into the blood of Rh-negative person, previously formed antibodies will cause the destruction of red blood cells of the transfused blood. Therefore, blood transfusion must take into account compatibility and the Rh factor.
Long ago, doctors noticed a heavier, in the past, often fatal disease of infants – hemolytic jaundice. Moreover, in one family several children fell ill, which suggested the hereditary nature of the disease. The only thing that did not fit into this assumption is the absence of signs of illness in the first born child and the increase in the severity of the disease in the second, third and subsequent children.
It turned out that hemolytic disease of the newborn is caused by the incompatibility of the erythrocytes of the mother and fetus by the Rh factor. This happens if the mother has Rh-negative blood, and the fetus inherits from the father Rh-positive blood. During the period of intrauterine development, the following occurs (Fig. 13). Erythrocytes of the fetus, having a Rh factor, getting into the blood of the mother, the erythrocytes of which do not contain it, are there alien antigens, and antibodies are produced against them. But the mother’s blood substances through the placenta again enter the child’s body, now having antibodies against the red blood cells of the fetus.
There is a Rhesus-conflict, resulting in the destruction of the red blood cells of the child and the disease hemolytic jaundice.
Fig. 13. Scheme of hemolytic disease of the newborn. Having designated the Rh factor by the + sign, it is easy to trace its path: it is passed from the father to the fetus, and from it to the mother; the Rh antibodies formed in her body (circles with arrows) return to the fetus and destroy its red blood cells
With each new pregnancy, the concentration of antibodies in the mother’s blood increases, which can even lead to the death of the fetus.
In the marriage of Rh-negative men with Rh-positive women, children are born healthy. Only a combination of Rh-negative mother and Rh-positive father can lead to the child’s illness.
Knowledge of this phenomenon makes it possible to plan in advance preventive and curative measures, with the help of which 90-98% of newborns can be saved today. To this end, all pregnant women with Rh-negative blood are taken on a special account, their early hospitalization is carried out, Rh-negative blood is prepared in case of an infant with signs of hemolytic jaundice. Exchange transfusions with the introduction of Rh-negative blood save these children.
There are two methods of blood transfusion. With direct (direct) transfusion blood using special devices directly from the donor is transfused to the recipient (Fig. 14). Direct blood transfusion is rarely used and only in special medical institutions.
For indirect transfusion the blood of the donor is preliminarily collected in a vessel, where it is mixed with substances that prevent its coagulation (most often sodium citrate is added). In addition, preservatives are added to the blood, which allow it to be stored in a form suitable for transfusion for a long time. Such blood can be transported in sealed ampoules over long distances.
Fig. 14. Syringe for direct blood transfusion
Fig. 15. Blood transfusion system: 1 – needle; 2 – viewing glass tube; 3 – ampoule with blood; 4 – connecting tube; 5 – tee; 6 – cylinder to create pressure; 7 – manometer
During transfusion of canned blood, a rubber tube with a needle is inserted onto the end of the ampoule, which is then introduced into the patient’s cubital vein (Fig. 15). Put the clip on the rubber tube; it can be used to regulate the rate of blood injection – fast (jet) or slow (drip) method.
In some cases, it is not the whole blood that is transfused, but its constituent parts: plasma or erythrocyte mass, which is used in the treatment of anemia. Platelet mass is transfused with bleeding.
Despite the great therapeutic value of canned blood, there is still a need for solutions that can replace blood. Many recipes for blood substitutes have been proposed. Their composition is more or less complex. All of them possess some of the properties of blood plasma, but do not have the properties of uniform elements.
Recently, for medicinal purposes, using blood taken from a corpse. The blood extracted in the first six hours after the sudden death from an accident, retains all the valuable biological properties.
Transfusion of blood or its substitutes has become widespread in our country and is one of the effective ways to save life in case of large blood loss.
Blood transfusion made it possible to revive people who were attacking clinical death, when heart activity stopped and breathing stopped; irreversible changes in the body while not yet occur.
The first successful dog revival was carried out in 1913 in Russia. Three to 12 minutes after the onset of clinical death, the dog was injected with blood into the carotid artery in the direction of the heart, to which blood-stimulating substances were added. The blood introduced in this way was sent to the vessels supplying the heart muscle with blood. After some time, the heart activity was restored, then breathing appeared, and the dog came to life.
In the years of the Great Patriotic War, the experience of the first successful revivals in the clinic was transferred to the conditions of the front. Infusion of blood under pressure in the arteries in combination with artificial respiration returned to the life of the fighters who were brought to the marching operating theater with cardiac activity that had just ceased and stopped breathing.
The experience of Soviet scientists shows that with timely intervention it is possible to achieve recovery after fatal blood loss, with injuries and some poisonings.
Despite the fact that a large number of different blood substitutes have been proposed, the natural blood of a person is still the most valuable for transfusion. It not only restores the constancy of the volume and composition of the internal environment, but also heals. Blood is needed to fill the heart-lung apparatus, which for some operations replace the heart and lungs of the patient. An artificial kidney requires from 2 to 7 liters of blood to work. A person with severe poisoning is sometimes transfused with up to 17 liters of blood for salvation. Many people were saved thanks to timely blood transfusion.
The people who voluntarily donate their blood for transfusion – donors – are deeply respected and recognized by the people. Donation is an honorary public function of a citizen of the USSR.
Any healthy person who has reached the age of 18, regardless of gender and type of activity, can become a donor. Taking a small amount of blood from a healthy person does not adversely affect the body. Hematopoietic organs easily replenish these small blood losses. About 200 ml of blood is taken from the donor at a time.
If you make a blood test from a donor before and after blood donation, then it turns out that immediately after taking blood, the content of red blood cells and leukocytes in it will be even higher than before it was taken. This is explained by the fact that in response to such a small blood loss, the body immediately mobilizes its forces and the blood in the form of a reserve (or depot) enters the bloodstream. Moreover, the body compensates for the loss of blood, even with some excess. If a person regularly donates blood, after a while the content in his blood of red blood cells, hemoglobin and other components becomes higher than before he became a donor.
Questions and tasks to the chapter The internal environment of the body
1. What is called the internal environment of the body?
2. How is the constancy of the internal environment of the body maintained?
3. How can you speed up, slow down or prevent blood clotting?
4. A drop of blood is placed in a 0.3% solution of NaCl. What happens to red blood cells? Explain this phenomenon.
5. Why does the number of erythrocytes in the blood increase in mountainous areas?
6. What donor’s blood can you transfuse if you have blood type III?
7. Calculate how many percent of students in your class have blood of I, II, III and IV groups.
8. Compare blood hemoglobin levels to several students in your class. For comparison, take the data of experiments obtained in determining the hemoglobin content in the blood of boys and girls.