Blood Groups.
Blood is comprised of red blood cells, white blood cells, plasma and platelets.
The red-cells transport oxygen to other body cells, white blood cells defend
body’s mechanism. Platelets help to clot; plasma is where protein of the body resides.
Technically, blood is a transport liquid pumped by the heart, to all parts of
the body, after which it is returned to the heart to repeat the process.
Blood is both a tissue and a fluid. It is a tissue because it is a collection
of similar cells that serve a particular function. These cells are suspended
in a liquid matrix--called plasma--which makes the blood a fluid.
In single-celled animals and the smallest multi-cellular invertebrates
there is no blood system.
Because of their small size, these animals can absorb oxygen and
nutrients and can discharge wastes directly into their surrounding medium.
Sponges and coelenterates (e.g., jellyfish and hydras) also lack a blood system;
the means to transport foodstuffs and oxygen to all the cells of these larger
Multi-cellular animals is provided by water, sea or fresh, pumped through
spaces inside the organisms.
Blood groups are determined by the red blood cells of the body. Antigens are
Tiny markers present on the surface of red blood cells. Antigens are unique for
every individual. They help to determine a person’s blood group and during
blood transfusion, antigens need to be matched correctly.
Human blood plasma contains cells of some other people’s blood.
Main Blood Groups are called A. B. AB and O.
Plasma of group A blood contains an anti-B factor and vice-versa so that
people of group A and B can not accept each other’s blood.
Group AB contains neither anti-A or anti-B factor and people in this
Group can receive transfusions from both but can give to neither.
Group O contains both anti-A and anti-B factor and can receive
Transfusion from only O group but can give blood to all groups.
It is important that transfused cells should not be agglutinated by
the factors in the recipient’s plasma.
Apart from the so called A B O system there is Rh system.
Everybody is either Rh(+) or Rh (-).
Rh system is inherited separately from the A B O group so that
One may be ARh(+) or ARh(-).
Both positive, negative factors are antigenic that is if introduced
In other’s blood they will stimulate the production of substances
Which act in some way against the cells introduced.
We inherit some factors from each parent and it may occur that a
Rh(+) baby is born out of a Rh(-) mother.
The method of classifying human blood on the basis of the inherited properties of red blood cells as determined by their possession or lack of the so-called antigens
A including A1 and A2 and B.
Persons may, thus, have type A, type B, type O, or type AB blood.
The A, B, and O blood groups were first identified by the Austrian immunologist Karl Landsteiner in 1901.
An antigen is a substance that can, in certain circumstances, excite the production of a corresponding antibody.
An antibody is a substance capable of reacting specifically with particular antigens. Blood group antigens are carried on the surface of the red cells.
Blood containing red cells with type A antigen on their surface has in its serum (fluid) antibodies against type B red cells.
If, in transfusion, type B blood is injected into persons with type A blood, the red cells in the injected blood are destroyed by the antibodies in the recipient's blood.
In the same way, type A red cells are destroyed by anti-A antibodies in type B blood.
Type O blood can be injected into persons with type A, B, or O blood unless there is incompatibility with respect to some other blood group system also present.
Persons with type AB blood can receive type A, B, or O blood.
Blood group O is commonest throughout the world, reaching a frequency of 100 percent in Amery-Indians of South and Central America and in the southern two-thirds of the United States.
Type B is high in Asia, with a maximum in Northern India; it is low in Europe and Africa and absent among American Indians and in most Australian Aborigines.
Type A1 is common all over the world and appears to exist to the exclusion of type A2 among the Australian Aborigines and Eskimos and in parts of Indonesia, the Pacific, India, Canada, and the northern United States.
Stomach cancer is 20 percent more frequent in persons of type A than in people of types O or B. Pernicious Anaemia and possibly bronchopneumonia in infants are also associated with type A.
Type O is associated with a 40 percent higher frequency of duodenal ulcer, especially in persons who do not secrete water-soluble antigen (consecrators). Gastric ulcer is also more frequent in type O individuals. Erythroblast sis fetalis (a type of anaemia) occurs in offspring of ABO-incompatible mating, particularly when the mother is O and the father A. Early loss of embryos is also increased in ABO-incompatible mating.
The ABO antigens are developed well before birth and remain throughout life.
ABO antibodies are acquired passively from the mother before birth, but by three months the infant is making his own. It is believed the stimulus for such antibody formation is from contact with ABO-like antigenic substances in nature.
A.B. O and Rh blood type distribution in India.
Population. O+ A+ B+ AB+ O(-) A(-) B(-) AB(-).
1.2billion. 34% 22% 33% 6% 2% 1% 1% 1%
*This article of information is for general knowledge.
