Wednesday, October 29, 2008
Emphysema causes inflammation in the walls of your alveoli – where CO2 and oxygen in the blood are exchanged – making them lose elasticity.
Eventually, the bronchioles of the lungs collapse, trapping air in the alveoli. They overstretch and interfere with the body’s ability to exhale, eventually rupturing and forming larger pockets of air. This forces the afflicted to breathe even harder in attempt to metabolize CO2.
There are two kinds of breathing: ACTIVE and PASSIVE. Passive breathing is done at rest. Your diaphragm contracts and your chest muscles expand to take air in, and then the elastic tissue around your air sacs contracts and your lungs passively shrink.
With active breathing during physical exertion, you need more oxygen, so your chest muscles contract and force air out rapidly. Emphysema destroys these elastic fibers and you must force air out of your lungs, compressing many of your small airways, making expelling air even more difficult.