The
major function of this system is the delivery of air to sites in the
lungs where gas exchange can occur between the air and circulating
blood.
The
effects of aging on the lungs are physiologically and anatomically
similar to those that occur during the development of mild emphysema.
Although aging affects ventilation, gas exchange, compliance, and other
parameters of lung function as well as the defense mechanisms of the
lungs, pure age-related changes do not lead to significant airway
obstruction in the nonsmoker.
Many
factors interact to reduce the efficiency of the respiratory system in
elderly individuals. Elastic tissue deteriorates throughout the body
and reduces the lungs’ ability to inflate and deflate. The
rib cage does not move as freely because of arthritic changes. This, in
combination with the changes in elasticity, causes a reduction in chest
movement which limits respiratory volume. These changes contribute to
the reduction in exercise performance and capabilities seen with
increasing age.
Finally,
some degree of emphysema is normally found in people aged 50-70. On
average, roughly 1 square foot of respiratory membrane is lost each
year after age 30. However, the extent varies widely depending upon the
lifetime exposure to cigarette smoke and other irritants. |
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Not
so fun fact:
Emphysema
is a chronic, progressive condition characterized by
shortness of breath and an inability to tolerate physical exertion. The
underlying problem is destruction of respiratory exchange surfaces. As
the condition progresses, the reduction in exchange surface limits the
ability to provide adequate oxygen. The condition is widespread and is
to some degree a normal consequence of aging. An estimated 66% of adult
males and 25% of females have detectable areas of emphysema in their
lungs. Unfortunately, the damage is irreversible. |
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