Anatomical barriers & their defense mechanismsAnatomical barriers Additional defense mechanismsSkin Sweat, desquamation, fushing, organic acidsGastrointestinal tract Gut motility / Peristalsis, gastric acid, bile acids, digestive enymes, thiocyanate,defensins, gut fora!es"iratory airways and lungs#ucociliary elevator, surfactant, defensins$aso"haryn% #ucus, saliva, lysoyme&yes 'ears