a A lung scan reveals cancer of the lung The colours in the healthy lung

A a lung scan reveals cancer of the lung the colours

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(a) A lung scan reveals cancer of the lung. The colours in the healthy lung indicate normal ventilation. On the left side, the absence of the normal colours and the presence of the purple colour indicate a nonfunctioning lung. (b) Smoke descends toward the lungs. (c) Postmortem specimen of a human lung shows a cancerous tumour of the upper lobe as a black and white area. The entire lung is permeated with black, tarry deposits, suggesting a history of heavy smoking. (a) (b) (c) Simulation—AsthmaBronchial asthmais associated with the inflammation of the bronchioles. In asthma, greatereffort is required to exhale than to inhale. The imbalance between the amount of air enteringthe lungs and the amount of air leaving the lungs must be met by increasing the exertion ofexpiration. In this activity, you will view the events that occur in the lung during an asthmaattack. Why does the imbalance in the amount of air entering and leaving the lungs occur?WEBActivityGObronchial asthmaa respiratorydisorder characterized by reversiblenarrowing of the bronchial passages
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296Chapter 9NELcells produce mucus, which is designed to trap foreignparticles. Compare the mucous layers in Figures 8 (a) and(c). Ciliated cells line the bronchioles. Cilia sweep away the Figure 8 (b)shows thebeginning of a cancerous tumour and Figure 8 (c)showshow the tumour advances. Note the location of the tumour andits growth. While the tumour is still walled in by the basalmembrane in Figure 8 (c), it has broken through themembrane in Figure 8 (d) . 25 20 15 10 5 1 current smoker 1–3 years 4–6 years 7–12 years 13+ years non- smoker quit smoking Smoking Status Risk of Smokers and Nonsmokers Developing Lung Cancer Persons Developing Lung Cancer (%) Figure 6 When smokers stop smoking, their risk of lung cancer decreases with time. Figure 7A comparison of the bronchioles and alveoli of a smoker and anonsmoker (a) normal (b) cancer develops (c) cancer advances tumour narrowed bronchiole (d) cancer impairs breathing cancer cells mucus cilia goblet cell basal cell Figure 8 Development of a tumour in the tissues of the bronchiole walls Case Study Questions
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