They are nonspecific. Compose structure chemicals and processes that prevent pathogens from entering the human body. Skin and mucous membrane are part of the innate defense system. Role of skin in innate immunity It has a chemical that defends against pathogens Perspiration secreted by sweat glands Salt inhibits the growth of pathogens Antimicrobial peptides act against microorganisms Lysozymes destroys the cell wall of bacteria Sebum secreted by sebaceous oil glands It helps keep skin pliable and less likely to break or tear Lower skin pH to a level inhibitory to many bacteria