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CIRCULAR
List of All blood banks
Camp Permitted Blood Banks
Performance of GSCBT till Mar-2011
Performance of Blood Safety Programme
Posters
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What is Blood? |
Blood is comprised of elements called cells suspended in
a pale yellow fluid known as plasma. Each drop of blood contains primarily three
types of cells - about 250 million red corpuscles, 400, 000 white corpuscles and
15 million platelets. Each of them plays a part in keeping the body healthy.
Blood is red in colour. This red colour comes from red blood cells. These cells
contain a substance called haemoglobin, a combination of iron and other materials
that give them the red colour. Haemoglobin makes it possible for red cells to pick
up oxygen from the lungs and to carry the oxygen to all parts of the body. The trillions
of cells that make up the body need oxygen to survive. As such, the red blood cell
distributes its load of oxygen, it picks up carbon dioxide waste from the body cells
and takes it to the lungs to be breathed out. Red blood cells have no power to move
on their own. They must be pumped throughout the body in the blood stream. The red
cells are manufactured in the bone marrow of the larger bones of the body.
The red cells are continuously at work and they have an average life span of 120
days. New ones are made constantly at a rate of millions per second. Old blood cells
are sent to an organ called spleen, where they are taken apart. The wastes are disposed
of and iron is recycled to go into new red blood cells. Certain food such as red
meat, cereals and green vegetables provide the body with iron. For donating blood
one must have at least 12. 5 gm. of haemoglobin per 100 ml of blood.
There are several types of white blood cells. Together these cells provide an active
defence to protect the body when it is invaded by bacteria, viruses or other harmful
substances. 60 to 70 percent of the white cells have a very simple mission. Their
job is to attack and literally eat up bacteria and other harmful substances. They
are the body’s first line of defence against infection and many illnesses.
Another very important group of white blood cells protect the body against catching
the same disease over and over again. These cells are especially effective against
many diseases that are caused by bacteria and viruses
Many common diseases, such as chickenpox, are caused by viruses.The first time one
of these diseases is caught, it triggers an immediate reaction from these special
white blood cells. They begin to produce a substance called antibody meant to fight
the virus. The antibodies are produced too late to prevent the first occurrence
of the disease. However, the antibodies are stored away available to prevent the
disease from occurring a second time. A different type of specific antibody is produced
for each type of virus that causes disease
The white blood cells use the blood stream as a highway in order to rush to the
site of an infection or illness. White cells are larger than red cells. They also
have the ability to change shape in order to pass through the narrow twisting capillaries.
White cells can get through some tight spots. Pus formed is actually the dead bodies
of white cells
Platelets are tiny irregular shaped cells and. like red blood cells, are made in
the bone marrow. Platelets are sticky. They can and do stick to each other and to
the inner surfaces of blood vessels. When a blood vessel cut or punctured, platelets
begin to gather at the site of the injury. The platelets stick to each other and
to the edges of the injury, forming a plug that reduces the loss of blood. As the
plug gets bigger, it becomes more solid and firm. It becomes a clot or scab, stopping
the flow of blood and providing a foundation upon which the healing process can
take place.
The fluid part of blood called plasma carries all cells. 55% of blood consists of
plasma while cells constitute 45% of the blood. Out of the 55% of plasma, 92% is
water. The balance 8% of plasma consists of proteins, sugar, fats, vitamins and
minerals that are needed by the body cells. In addition, plasma contains antibodies
and hormones. Hormones are chemical messengers that regulate growth, physical responses
to emotions and other body functions.
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