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Unformatted text preview: Lung -- Review Questions 1. A century ago, workers in the big silver mines of Virginia City, NV had a life expectancy of less than a year due to lung disease. Assuming the massive quantities of dust they inhaled had the same effect as respirable silica, outline a plausible mechanism for the production of their fatal pulmonary fibrosis. Macrophages engulf the dust particles and are eventually killed. However, during this process, they release: (1) Recruitment factors (cytokines and chemokines) for more macrophages, neutrophils, and other immune cells such as T cells. Recruited macrophages repeat the cycle and amplify the process. (2) Growth factors which stimulate fibroblast proliferation and increase the rate of collagen synthesis. (3) Oxygen radicals (i.e. superoxide) and proteases which kill the lung epithelial cells allow for the overgrowth of fibroblasts. Overall result: Loss of normal architecture leads to stiffening of the lung and a thickening of the inter- stitium (tissue lining and separating the alveoli). Breathing becomes difficult and gas exchange is reduced....
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- Winter '06
- obstructive lung disease