The Permanent Enlargement Of The Alveoli Essay

2136 WordsNov 15, 20169 Pages
EMPHYSEMA Defined as the permanent enlargement of the alveoli. Typically, the alveoli are tiny, grape-like clusters that allow for greater surface area for gas exchange. In emphysema, the grape-like clusters are destroyed, leaving behind one large “bleb” alveoli that is difficult to ventilate without increased air-trapping. Once the inhaled air becomes trapped in the bleb, additional oxygen-rich air is unable to enter the bleb. CHRONIC BRONCHITIS Defined as a productive cough that last for at least three months in each of at least 2 consecutive years. All other reasons for a productive cough, such as pneumonia, are ruled out prior to diagnosis of bronchitis. Risk factors: • Cigarette smoking o Especially in people over the age of 40 with 10 or more pack-years. o Smoking causes cell hyperplasia especially in the goblet cells. This leads to increased mucus production. Cell hyperplasia also causes the diameter of the airways to shrink making it harder to clear the excess amounts of mucus being produced by the hyperplastic goblet cells. o Cigarette smoke also paralyzes cilia necessary to move mucus up the airways. With enough exposure, the cilia can actually be destroyed. o Smoking also can break down the grape-like clusters of the alveoli leading to blebs that are hard to ventilate and lead to air-trapping of CO2 rich air. o Smoke can also cause chronic inflammation that leads to airway remodeling due to scarring. o Smoking can also constantly irritate the cells of
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