Defense Systems of the Lung

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Lectures on respiratory physiology
Defense Systems of the
Lung
Atmospheric Pollutants
Carbon monoxide
Sulfur oxides
Nitrogen oxides
Hydrocarbons
Particulates
Photochemical oxidants
Types and sources of pollutants
Perfect Lung
Photochemical Oxidants
hydrocarbons
ozone, peroxyacyl nitrate,
sunlight
nitrogen oxides
aldehydes, acrolein, etc.
Examples of smog
Perfect Lung
Insidious effects of
tobacco advertising
Effects of cigarette smoke
Carbon monoxide causes up to 10% hemoglobin
“Tars” cause bronchial carcinoma
Smoking causes chronic bronchitis, emphysema,
bronchial carcinoma and coronary heart disease
Cancer death rates (male) from 1930 to 2004
Effect of single cigarette on airways
Behavior of Aerosols
in the Lung
Deposition
Clearance
Mechanisms of deposition of aerosol
Perfect Lung
Sites of aerosol deposition
Perfect Lung
Mechanisms of deposition of aerosol
Perfect Lung
Accumulation of dust in a coal-miner’s lung
Mechanisms of deposition of aerosol
Perfect Lung
Clearance of Deposited
Particles
Mucociliary system
Alveolar macrophages
Clearance of deposited particles
Mucociliary escalator
Airway wall showing a mucous gland
Normal airway (above); Enlarged mucous glands (below)
Goblet Cell
Mucociliary escalator
Gel layer of the mucus above the sol layer
Cilia just touching the gel layer
Ciliary action
Structure of microtubule; diagram (left), EM (right)
Impairment of Normal
Mucociliary Function
Mucus:
too much, or change in
composition, e.g. chronic
bronchitis, cystic fibrosis, asthma
Cilia:
paralysis by toxic gases
bronchial epithelium destroyed
congenital defect of ciliary motion
Alveolar Macrophage
Alveolar macrophage in the corner of an alveolus
Impairment of Normal
Macrophage Function
Inhaled gases such as ozone, cigarette
smoke
Toxic particles such as silica
Alveolar hypoxia, radiation,
corticosteroids, alcohol ingestion
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