Skin: Provides an impervious barrier so entry of
micro-organisms is stopped. Bacteria on the skin
also prevent establishment of pathogens. Sebum
and sweat secreted to the surface of the skin
prevent growth and kill pathogen
Eyes: Tears contain lysozyme,
an enzyme that kills bacteria
Ears: Cerumen (ear wax) inhibits
bacterial growth
Nasal Cavity: Hairs
and mucous trap
micro-organisms