Angela Bryan, age 9, of Champaign, I11., for her question.
WHAT EXACTLY IS BLOOD PLASMA?
Plasma is the straw colored liquid part of blood that remains when the red and white blood cells are removed. Blood plasma contains water, salts, proteins and other materials.
Plasma actually carries dissolved food materials to all parts of the body. It also picks up waste materials, produced by the body cells, and carries them to the organs that remove wastes from the body. In addition, plasma carries secretions from certain glands in the body.
Fibrinogen is the name of one of the proteins found in blood plasma. If it were not for this remarkable substance, you would bleed to death from the slightest cut. Fibrinogen makes it possible for the blood to clot and seal off the wound.
Another protein is called globulin. Globulin in the plasma carries disease fighting substances known as antibodies. These are produced by your body when you have a disease.
A third protein found in plasma is called albumin. It helps keep the blood volume and blood pressure normal.
It was discovered during the 1930s that plasma could be separated from whole blood. Plasma is obtained by separating out the blood cells in a machine called a centrifuge. The liquid plasma can be kept for a much longer time than whole blood. Plasma also may be dried or frozen and kept indefinitely.
Plasma is used for blood transfusions when whole blood is not needed or cannot be obtained. It also is used to restore blood volume lost during severe bleeding.
Plasma often is used during operations to combat the condition known as shock. It works almost as well as whole blood in treating shock and in replacing blood depleted during bleeding.
In certain diseases, the body literally is starved for protein that has been broken down to a useable form. Scientists have learned how to produce such substances from plasma.
The antibodies produced by your body when you have a disease destroy germs and help protect you from getting the disease again. When this occurs, you have developed an immunity to the disease.
Most antibodies are concentrated in a portion of the globulin protein called the gamma globulin. Doctors use gamma globulin to help prevent infectious jaundice, measles and other diseases.
Scientists have tried to find safe substitutes for plasma. But substitutes are not as effective as whole blood or plasma.
Plasma makes up about 55 to 65 percent of the total volume of blood.
Plasma contains water, salts, proteins, various minerals and dissolved gases. In addition, it carries chemical substances called hormones from one part of the body to another.