Image: Canva
Lung defence includes mucus, epithelial barriers, and immune cells protecting against infection and environmental damage
Image: Canva
Pulmonary epithelium senses threats and activates innate immune responses to protect lung tissue
Image: Canva
Smoke increases mucus production but reduces its clearance, causing mucus build-up in airways
Image: Canva
Smoking impairs lung defences, raising susceptibility to infections and chronic airway inflammation
Image: Canva
Tobacco smoke disrupts epithelial tight junctions, weakening the lung’s protective barrier
Image: Canva
Damaged lung tissue recruits immune cells like phagocytes and lymphocytes to fight injury
Image: Canva
Lymphocytes form organised follicles with germinal centres, enhancing adaptive immune responses in lungs
Image: Canva
Lymphoid follicles increase from about 5% in smokers to 20–30% in advanced COPD
Image: Canva
The antigen triggering adaptive immunity in COPD is unknown, possibly microbial in origin
Image: Canva
Inflammation persists after quitting smoking, though cessation slows lung function decline and improves survival