The second major type is that in which emphysema is the primary underlying process. Emphysema is defined by destruction of airways distal to the terminal bronchiole.
Physiology of emphysema involves gradual destruction of alveolar septae and of the pulmonary capillary bed, leading to decreased ability to oxygenate blood. The body compensates with lowered cardiac output and hyperventilation. This V/Q mismatch results in relatively limited blood flow through a fairly well oxygenated lung with normal blood gases and pressures in the lung, in contrast to the situation in blue bloaters. Because of low cardiac output, however, the rest of the body suffers from tissue hypoxia and pulmonary cachexia. Eventually, these patients develop muscle wasting and weight loss and are identified as "pink puffers."
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Chronic obstructive pulmonary disease (COPD). Histopathology of chronic bronchitis showing hyperplasia of mucous glands and infiltration of the airway wall with inflammatory cells.
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Chronic obstructive pulmonary disease (COPD). Histopathology of chronic bronchitis showing hyperplasia of mucous glands and infiltration of the airway wall with inflammatory cells (high-powered view).
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Posteroanterior (PA) and lateral chest radiograph in a patient with severe chronic obstructive pulmonary disease (COPD). Hyperinflation, depressed diaphragms, increased retrosternal space, and hypovascularity of lung parenchyma is demonstrated.
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Chronic obstructive pulmonary disease (COPD). A lung with emphysema shows increased anteroposterior (AP) diameter, increased retrosternal airspace, and flattened diaphragms on lateral chest radiograph.
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Chronic obstructive pulmonary disease (COPD). A lung with emphysema shows increased anteroposterior (AP) diameter, increased retrosternal airspace, and flattened diaphragms on posteroanterior chest radiograph.
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Subcutaneous emphysema and pneumothorax.
