Physical, chemical and mirobiota barriers

physical barriers

innate barriers that act to prevent the entry of pathogens into the body

chemical barriers

innate barriers that use enzymes to inhibit the growth or development of pathogens and/or act to destroy pathogens

microbiological barriers

innate barriers involving normal flora in the body that prevent the growth or colonisation of microorganisms that may be pathogenic.

Intact skin

an important physical and chemical barrier to microbial infection, constant shedding of dead skin cells is an effective barrier

Mucous membranes

inner spaces of airways, the gut and urogenital tract are lined with mucous membranes consisting of epithelial cells, secrete mucus that traps pathogens and is then destroyed by stomach acid or expelled from the body

lysosome

sweat, mucus, tears and saliva all contain an enzyme called lysosome that kills pathogens