Chronic Obstructive
Pulmonary Disease (COPD)
-Brief Overview of
COPD-
Chronic obstructive
pulmonary disease is a group of diseases that includes emphysema, chronic
bronchitis, asthma, and a combination of the three. Most people with COPD
have a combination of these with lung irritation. The damage to the airways
and broken-down alveoli is healed by scar tissue. This scarring becomes
structure and can progress, but cannot return to oxygen-exchanging normal
lung tissue.
-Effects of COPD-
Emphysema
In emphysema the
alveoli, or tiny air sacs in the lungs, no longer are elastic and behave
more like paper bags than rubber balloons. A paper bag does not stretch like
a balloon and no longer can empty simply by relaxing. In addition to losing
their elasticity, some of the air sacs break down and there are fewer sacs
to be filled. Inadequate available alveoli and capillaries to exchange
oxygen cause the individual to be short of breath. Another reason for
shortness of breath is that the air sacs do not empty completely and stale
air with a higher proportion of carbon dioxide stays in the lungs. The fresh
air cannot get in. The smaller airways become weaker and collapse when an
attempt is made to force air out too quickly or too forcibly. This traps
more stale air in the alveoli.
Thus in emphysema, the
major problem is decreased available functioning air cells with which to
exchange oxygen and carbon dioxide. Activity requires more available oxygen.
The person with emphysema becomes fatigued and out of breath easily. The
causes of emphysema are unknown, but major contributing factors are:
Asthma
With asthma, the irritation causes
the airways to become narrow and to close temporarily. This is called a
bronchospasm. Wheezing is heard as air tries to pass through narrow and
clogged airways. With bronchospasm, the problems are the same as for chronic
bronchitis. The difference is that with asthma, allergies to certain
substances or emotional crises trigger an attack, and the airways stay
narrow temporarily.
Chronic Bronchitis
In chronic bronchitis, the branches
or bronchioles become inflamed or remain narrow because of constant
irritation.
Narrow airways make it more
difficult to get air out of the lungs. Chronic irritation causes more mucus
production and more coughing, which further irritates the bronchioles. With
the excess coughing, the diaphragm flattens, replacing the dome shape. When
flattened, the diaphragm does not function as an effective bellows for its
job of expanding the chest capacity for air exchange. Major causes of
bronchitis also are cigarette smoking, air pollution, and repeated chest
colds.
-Links to Other
Informative Sites-
Last updated: 3-4-2008
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