Lung Defence Part 1 PDF
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Uploaded by Christy Forwood
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Summary
This document describes the defense mechanisms of the lungs, focusing on the mucociliary escalator and airway surface liquid (ASL). It explains how the lungs protect against pathogens and foreign material. The document also briefly discusses other factors in innate immunity.
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21/02/24 Lung defence: part 1 How does the lung defend itself: This is done by the muco-ciliary escalator. Ciliated air way epithelial cells. Air ways surface liquid ( ASL ). upper surface liquid Peri get ciliary PCL layer Sol mucins layer liquid Goblet cells secrete the mucus/ gel layer. AKA Sol Th...
21/02/24 Lung defence: part 1 How does the lung defend itself: This is done by the muco-ciliary escalator. Ciliated air way epithelial cells. Air ways surface liquid ( ASL ). upper surface liquid Peri get ciliary PCL layer Sol mucins layer liquid Goblet cells secrete the mucus/ gel layer. AKA Sol The PCL is more liquid-like, which allows the cilia to waft and without it the cilia would have to ght against the sticky/ treacle-like mucus. Maintaining the airway surface liquid Maintenance of ASL is critical; too much/ too much mucus means the cilia will collapse down: and too little means you won’t catch anything at all. The liquid is constantly being absorbed through the apical cell membrane. This is the membrane facing into the air way. Volume absorption driven through sodium transport. ENaC brings sodium back into the cell when the uid is getting to high, and then water will follow back into the cell. CFTR is a chloride channel, it pumps chloride out of the cell to maintain the volume; water follows it too. The CRTR can also inhibit the ENaC. Other factors in innate defence: Molecules in ASL, such as defensins and opsonins. Scavenging cells: alveolar macrophages, neutrophils and chronic in ammatory cells.
