Wherever you are in the world, blood has very important cultural
meaning. It is often seen as a life force, and as a symbol
of family and kinship ties. It may even equate with personality
and appearance.
Blood carries vital nourishment to all the tissues and organs
of the body. Without blood the tissues die of starvation.
In the womb, for example, the mother's blood ensures that
the foetus is supplied with oxygen and nutrients and benefits
from the mother's inbuilt defenses against diseases. The average
person has 25 billion red blood cells, and in a normal healthy
person cells are constantly regenerated in the body.
About 45 per cent of the total volume of blood is made up
of:
Red Blood Cells
White Blood Cells
Platelets
The remaining 55 per cent is called plasma. Red blood cells
carry oxygen. The hemoglobin, which gives blood its red color,
is the agent, which needs to be present for oxygen to be taken
up from the lungs. Iron is a key factor in the manufacturing
of hemoglobin. When iron is low, people become anemic, with
a corresponding loss of oxygen-carrying ability. Red blood
cells also transport the used oxygen, transformed into carbon
dioxide, back to the lungs for expulsion from the body.
White blood cells defend the body against disease. They make
antibodies (natural defenses produced in the body against
infection) and fight infections.
Platelets help to control bleeding by sticking to injured
surface of blood vessels, and allowing clotting factors to
accumulate at the injury site.
Plasma is a fluid, which carries all these cells, plus other
substances such as proteins, clotting factors and chemicals.
Sometimes, through trauma such as hemorrhage (blood loss),
the volume of blood in the body reduces to such level that
the body cannot replace it fast enough. Occasionally, the
blood is faulty, and does not function properly, as in the
case where clotting does not occur, as in hemophilia (inherited
blood disorder), and where the body doesn't make blood that
is called Thallasaemia. At other times, the blood does not
produce sufficient hemoglobin. In many of these cases, blood
products will transfuse into patients. All the different components
of blood can be used and each component plays an important
role in saving the lives of different individuals in the community.
A healthy person can safely donate Blood every 56 days (4-6
times/year). After each withdrawal of blood it takes only
36 hours for the body to reconstitute the fluid volume and
21 days for the red blood cells to return to a normal level.
Education and information over a period of time can overcome
all barriers to blood donation.