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Immune
system
Syndicated from Better Health Channel
The
immune system is made up of special cells and chemicals that
fight infection. The white blood cells that make up the immune
system are made in the bone marrow. These cells move through
blood and tissue. Every time a microbe (germ) is overcome, that
microbe is remembered by the immune system. That means if the
body ever comes in contact with that particular microbe again,
it will be defeated very quickly.
The response to a cut
When skin is broken, microbes can enter the cut. The immune system
sets up a
defense to this invasion, which includes the following:
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White
blood cells, which circle the bloodstream on permanent
standby, 'hear' of the breach via a chemical alarm sent
out by damaged cells. They move to the cut and start 'eating'
the bacteria. Pus is actually dead microbes and dead white
blood cells.
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Lymphocytes are another type of immune system cell. B-lymphocytes try
to identify the microbe. If the microbe has been defeated before, the lymphocytes
know which antibodies have to be made in order to kill it.
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There are a number of different T-lymphocytes. Helper cells help the
B-lymphocytes to make antibodies. Killer cells attack infection. Suppressor cells
help to call a halt to the immune system response.
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The
lymphatic system
The lymphatic system is part of the immune system. It is made
up of lymph nodes that trap microbes, and the spleen (a blood-filtering
organ). Lymphocytes are
also found in the lymphatic system.
Fever
A rise in body temperature, or fever, can happen with some infections. This
is actually an immune system response. A rise in temperature can kill some
microbes
and fever also triggers the body's repair process.
The common cold
The immune system keeps a record of every microbe it has ever defeated. This
means it can destroy the microbe very quickly if it enters the body again,
before it can multiply and make you feel sick. Some infections, like influenza
and the
common cold, have to be fought time and time again. This is because there are
so many different viruses that can cause these illnesses. Catching a cold from
one virus doesn't give you immunity against the others.
Other defenses
As well as the immune system, the body has a number of other ways to defend
itself against microbes, including:
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Skin
- a waterproof barrier that secretes oil with bacteria-killing
properties.
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Lungs
- mucous (phlegm) traps particles, and small hairs
(cilia) wave the mucous upwards so it can be coughed
out.
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Digestive
tract - the mucous lining contains antibodies, while
the acid in the stomach can kill most microbes
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Common problems
Some common problems of the immune system include:
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Allergies
- the immune system reacts to a harmless substance
as if it were dangerous.
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Hay
fever - an allergy to pollen, common in Spring.
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Lupus
erythematosus - symptoms include skin rashes and painful
joints.
- Rheumatoid
arthritis - the immune system attacks the joint, causing
inflammation and swelling.
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Things
to remember
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The
immune system fights infection.
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It
keeps a record of every microbe defeated.
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Other
lines of defense include the skin, lungs and digestive
tract.
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