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How Your Lungs Work

Lung Failure

­­ There are many­ common conditions that can affect your lungs. We will describe some of the ones you hear about most often. Diseases or conditions of the lung fall mainly into two classes -- those that make breathing harder and those that damage the lungs' ability to exchange carbon dioxide for oxygen.

Diseases or conditions that influence the mechanics of breathing:

  • Asthma: The bronchioles constrict, reducing the size of the airways. This cuts down on the flow of air and makes the respiratory muscles work harder.
  • Emphysema: The lungs become stiff with fibers and become less elastic, which increases the wor­k of the respiratory muscles.
  • Bronchitis: The airways become inflamed and narrower, which restricts the flow of air and increases the work of the respiratory muscles
  • Pneumothorax: Air in the chest cavity equalizes the pressure in the chest cavity with the outside air and causes the lungs to collapse. This is usually caused by trauma or injury.
  • Apnea: Breathing slows or stops under a variety of conditions. There are many types of apnea, and they are usually caused by problems in the respiratory centers of the brain.

Diseases or conditions that minimize or prevent gas exchange:

  • Pulmonary edema: Fluid between the alveolus and pulmonary capillary builds up, which increases the distance over which gases must exchange and slows down the exchange.
  • Smoke inhalation: Smoke particles coat the alveoli and prevent the exchange of gases.
  • Carbon monoxide poisoning: Carbon monoxide binds to hemoglobin more tightly than either oxygen or carbon dioxide, which minimizes the delivery of oxygen to all the tissues of the body, including the brain, the heart and muscles. Carbon monoxide is a common product of poorly vented heaters (space heaters, furnaces, water heaters) and of automobile exhausts. This condition can be fatal if not caught soon after exposure.

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