Blood the elixir of life, is vital for effective functioning of the human body. The heart pumps and supplies blood through a network of arteries and veins, transporting essential nutrients and oxygen to the innumerable cells of the body. Blood helps eliminate waste and carbon dioxide from the body and helps combat infections.
Where is Blood formed?
Blood cells are formed in the bone marrow, which is a soft spongy jelly-like substance made up of certain cells, fat and blood besides other substances. Numerous types of red and white blood cells are formed in the bone marrow everyday with most of the bones producing blood, as in the case of children, although in adults only certain regions such as the pelvis ribs and spine form blood.
What is blood made up of?
The adult human body comprises of 4 to 6 litres of blood, which is roughly about 7 to 8 percentage of the total body weight.
Blood is a combination of red and white blood cells and platelets in a watery liquid form known as plasma. About 45% of the blood consists of cells while the remaining 55% comprises of plasma.
Plasma is a pale yellow liquid portion of the blood mostly made up of water, proteins, sugar, fat, potassium and calcium salts. One of the chief functions of plasma is to act as a carrier for blood cells, nutrients, enzymes and hormones. The Plasma, that transports blood to all the cells, enzymes and hormones also contains many chemicals that help blood to form clots necessary to stop bleeding.
Red Blood cells
The Red blood cells, known as erythrocytes consist of a special protein called haemoglobin that distribute oxygen to all parts of the body and eliminate carbon dioxide from the tissues. These cells make up 40 to 45 % of the blood with the haemoglobin containing iron that gives them the characteristic bright red colour.
White blood cells
The White blood cells or leukocytes produce proteins known as antibodies, which prevent the invasion of bacteria, viruses and other foreign bodies. These are circulated and transmitted in the body, where they finally reach the area of infection, to destroy the bacteria. Any increase in white blood cells indicates a possibility of infection in the body.
The platelets or thrombocytes are unevenly shaped, colourless cell fragments in the blood. They are sticky in nature and contain substances that form clots to protect bleeding. When bleeding occurs from a wound, certain chemicals are released in order to complete the process of blood clotting which stop bleeding. The platelets clump together, thereby obstructing blood flow.
What is a Blood Type?
Karl Landsteiner, an Austrian scientist, in the year 1901, illustrated that blood may be grouped into four Types namely A, B, AB and O. The protein molecules on the surface of the blood called antigens or agglutinogens and the antibodies present in the plasma ascertain the blood Type. These substances act as a natural defense against invasion of foreign bodies and prevent infection.
The ABO system of Blood Grouping
The four basic blood groups in combination within the ABO systems categorize each blood group.
Type A Blood Group
Type A is established when A antigens are present on the surface of the red blood cells with anti B bodies in the plasma.
Type B Blood group
Type B blood is determined with B antigens present on the surface of the red blood cells and antibodies A in the plasma.
Type AB Blood Group
The presence of both A and B antigens on the surface of the red blood cells along with the absence of A and B antibodies in the plasma make the AB blood group.
Type O Blood Group
The absence of both A and B antigens on the surface of the red blood cells combined with the presence of both A and B antibodies in the plasma is Typed as O blood group.
The Rh factors in the Blood
Another blood group system includes the Rhesus factor. This is determined with the presence or absence of a protein known as the RhD antigen. If this protein is present in the red blood cells then the blood group is termed RhD positive and if these proteins are absent they fall into the category of RhD negative. The term Rhesus is derived from the Rhesus monkeys because the RhD antigen proteins were first discovered in the blood of these species. These combined with the ABO system of blood grouping may fall one among the eight blood group Types known as A+, A-, B+, B-, AB+, AB-, O+, or O-.
Genetic Inheritance of Blood Types
Similar to the characteristic traits that an individual inherits from his parents, so also is the blood Type, which has a genetic inheritance. Each individual inherits one gene each from the parents, which according to scientific terminology are known as alleles, that determines a person’s blood Type. Whatever may be the blood group of the person like A, B, AB or O is based on the blood Types of both the parents. The gene for both Type A and B are dominant, while the gene for Type O is recessive. Therefore, a person with Type A could have a genetic combination of either AA or AO. This is because Type A make Type O gene obscure. The same aspect applies to Type B too. Unless a person has both Types as O, devoid of a dominant Type A or B gene, he cannot be categorized as Type O.
The possibility of a person’s blood group with genetic pairing is given below.
Blood Types Compatibility
The universal receiver is the AB+ blood group. Therefore, anyone belonging to this group may receive any other blood Type without any dangers involved.
AB- blood group may receive blood from any Rh-negative groups such as A-, B-, or O- to avoid any kind of complications.
A+ blood group may receive blood from groups A+, A- , O+, or O-, while A- may do so from A- and O-.
The donors for B+ may be from blood groups B+, B-, O+, or O-., wherein for B- may be B- or O-.
The universal donors are however grouping O- as they may donate blood to any blood Type without causing any kind of adverse reactions. This is because the blood, devoid of antigens may not attack the immune system of the person receiving it.
There are possibilities of the blood cells clumping together in the blood vessels when two different blood Types are mixed. This may lead to blockage of blood vessels followed by lack of blood circulation to various parts of the body. Besides these aspects, the red blood cells may crack because of clumping and there might be possibilities of leakage, leading to mortality. Therefore, it is highly imperative to match the blood Types to avoid harmful implications.
A Rh- expectant mother may endanger the foetus if the fathers blood Type happens to be Rh+. This way there are possibilities of the mother forming antibodies against the baby’s blood.
According to Japanese and Korean culture, it is believed that a person’s blood type reveals his/her personality. Just check the Japanese personality chart below.