The blood
The blood transports the nutritive principles from the digestive apparatus to the cells, where the waste substances are also collected to eliminate them thanks to the kidneys, the liver and other organs of excretion. It is also responsible for regulating the transport of oxygen and the elimination of carbon dioxide. It has an important role in functions such as coagulation, immunity and control of body temperature.
Source
Blood is living tissue formed by liquids and solids. The liquid part, called plasma, contains water, salts and proteins. More than half of the body is plasma. The solid part of the blood contains red blood cells, white blood cells and platelets.
Red blood cells supply oxygen from the lungs to tissues and organs. White blood cells fight infections and are part of the body's immune system. Platelets help your blood clot when you have a cut or wound. The bone marrow, the spongy material inside the bones, produces new blood cells. The blood cells constantly die and your body produces new ones. Red blood cells live about 120 days and platelets live close to six. Some white blood cells live less than a day, but others live much longer.
Components of blood
Blood is a substance composed of four main elements:
Erythrocytes or red blood cells
Also called red blood cells, they are cells responsible for the transport of oxygen from the lungs to the rest of the body, and in turn transport carbon dioxide from the cells to the lungs, for their elimination. They carry hemoglobin, responsible for the characteristic red color of the blood.
Leukocytes
Commonly known as white blood cells, it is a set of cells that are part of the immune system and that share the function of protecting the body against harmful agents.
Platelets or thrombocytes
They are cellular fragments that circulate in the blood. Their function is to act on coagulation (stop the circulation of blood) and on the healing of broken blood vessels to minimize losses.
Plasma
It is about the liquid part of the blood; It is basically made up of water and proteins. It provides a means of transport, in addition to participating in the immune defense (immunoglobulin or antibodies) and in coagulation (clotting factors). When the coagulation factors are eliminated, the plasma is called serum.
Discovery of blood groups
Nowadays, the blood group is something we know from the moment we are born, but before that it was not like that. It was Landsteiner who made it possible to differentiate the different blood types and thus give transfusions, operations and even paternity tests with total safety.
Son of a well-known journalist who died when he was six years old, Karl Landsteiner received his doctorate in Medicine in Vienna. There he held the Chair of Pathological Anatomy and his first research (first as an assistant and, from 1909, as a professor) focused on the genetics of human blood, which he compared with that of primates and other animals.
He observed that, when mixing the blood of two people, sometimes the red blood cells clumped together forming visible lumps.
He analyzed the blood of a total of 22 people, including his own and that of five collaborators in his laboratory. To do this, he first separated the serum from the whole blood, then washed the red blood cells and immersed them in a solution of physiological saline.
Finally, I tested each serum with the different red blood cells obtained and tabulated the results. He thus discovered three different types of red blood cells, called A, B and O, which generated agglutination reactions. These findings were made in Vienna around 1901. Two years later, two of his disciples, Alfredo de Castello and Adriano Sturli, analyzed 155 samples (of 121 patients and 34 healthy controls) and discovered a fourth group, which they called AB.
Human blood naturally possesses molecules known as antibodies, capable of reacting with other molecules of red blood cells called antigens or agglutinogens, resulting in their agglutination as a result of the antigen-antibody interaction.
These antibodies or isoagglutinins (which do not exist in type AB) are responsible for the incompatibility of blood transfusions if the blood to be transfused from the donor is not selected or typed (as it is technically called in the jargon of the laboratory). In 1911, Ottenberg coined the term "universal donor" for group O, for lack of antigens in erythrocytes. In 1908, Epstein and Ottenberg suggest that blood groups are hereditary.
In 1910, E. von Dungern and L. Hirszfeld discovered that the inheritance of these blood groups follows the laws of Mendel, with a dominant pattern for types A and B. In 1927, immunizing rabbits with Philip Levine, Landsteiner discovered three antigens more (M, N and P) similar to those of groups A and B. But, unlike these, their presence in red blood cells does not imply the existence of natural agglutinins in normal human blood.
In 1940, together with Alexander Salomon Wiener, he discovered another antigen in the red blood cells which he named Rh factor, because it was found in the serum of rabbits immunized with blood from an Indian monkey, the rhesus macaque (Macaca mulatta). A child who has the Rh factor, that is, is Rh +, can immunize his Rh-mother during pregnancy. It develops specific anti-Rh antibodies that, in their second pregnancy, can cross the placenta and produce an abortion or a haemolytic disease in the newborn with jaundice, the fetal fetal erythroblastosis. Later, Ronald A. Fisher described other systems of erythrocyte antigens and today a total of up to 42 different antigens are known in human red blood cells.
System ABO
It is the first system discovered to differentiate blood groups, and currently it remains one of the main ones. In this case, it is divided into four blood types: A, B, AB, and 0. The AB0 system was described by the biologist Karl Landsteiner in 1901, which earned him the Nobel Prize for Medicine in 1930.
This is based on the presence or absence of a carbohydrate in the cell membrane of erythrocytes. Although this is not exclusive to these cells, on the contrary, it is distributed in other types of cells, which is why it is also important in organ transplantation.
Rh Factor
Source
This criterion to demarcate blood types was also discovered by Landsteiner together with Alexander S. Wiener in 1940, and described for the first time in rhesus macaques; hence its name.
The incompatibility is due to the fact that the negative type has antibodies against the positive type, but it does not happen the other way round, that is, the positive type can receive Rh negative blood.
Why is it important to know the blood type?
The doctors indicate that it is very important to know our group and blood factor.
Why? Because in emergency situations where you need to receive or donate plasma you do not always have time to analyze it and determine this fundamental information.
Health professionals recommend carrying an identification with these data in your purse, a bracelet or a medal. It is very easy to know, only an analysis is needed.
The next time you have to do a medical checkup, ask for the study of your group and factor to be included if you do not know it or if you do not have it written down anywhere. It is common at birth for parents to receive a card with this information, but we do not always find it.
If you plan to donate blood you can also take advantage to find out your blood group. Do not forget that these data are not available instantly and you will probably have to wait a few days to find out.
You can also go to the hospital where you were born or you do your annual studies: they probably have that information in their database.
To discover the type of blood you have consult your parents by the factor of each one. There is a table to determine what your "options" are:
- Progenitor O and Progenitor O = child O
- Progenitor O and Progenitor A = child O or A
- Progenitor O and Progenitor B = child O or B
- Progenitor O and Progenitor AB = child B or A
- Progenitor A and parent A = child O or A
- Progenitor A and Progenitor B = child O, A, B or AB
- Progenitor A and Progenitor AB = son A, B or AB
- Progenitor B and Progenitor B = child O or B
- Progenitor B and Progenitor AB = child A, B or AB
- Progenitor AB and Progenitor AB = son A, B or AB
Blood can not be manufactured
All over the world, we depend on the generosity of the citizens so that the health care centers can perform transplants, operations and oncological treatments, among others.
Blood can not be stored indefinitely as it expires: platelets have to be used within five days, red blood cells before 42 days and plasma before one year.
Importance in blood donation
Blood types have a demographic distribution, the most common being type 0+, while the least common is type AB-. This is an important fact in the field of donation.
Generally, the 0- is the most demanded blood type, since it is known as the universal donor, to be able to be used for any case of transfusion to have no antigen (neither A, nor B, nor Rh +). However, people with 0- can not receive blood except the same type, because they have all the antibodies against the other types.
In contrast, the AB + has been called "the universal receiver", since it can receive any type of blood, by not presenting any of the antibodies against the rest. The downside is that you can only donate for people of the same type, because it presents all types of antigens.
For more information
https://psicologiaymente.net/salud/tipos-de-sangre
https://salud.uncomo.com/articulo/cuales-son-los-tipos-de-sangre-18491.html
https://mejorconsalud.com/por-que-son-especiales-las-personas-con-sangre-0/
https://www.muyinteresante.es/salud/preguntas-respuestas/por-que-es-tan-raro-encontrar-personas-con-tipo-de-sangre-ab-521465896731
https://es.wikipedia.org/wiki/Grupo_sangu%C3%ADneo
https://medlineplus.gov/spanish/blood.html
http://www.donasang.org/que-es-la-sang/es_index.html
http://www.salud.gob.ar/disahe/index.php?option=com_content&view=article&id=315&Itemid=39
https://es.wikipedia.org/wiki/Karl_Landsteiner