PATHOLOGY

Detailed explanation-1: -Mechanical barriers-which include the skin, mucous membranes, and fluids such as tears and urine-physically block pathogens from entering the body. Chemical barriers-such as enzymes in sweat, saliva, and semen-kill pathogens on body surfaces.

Detailed explanation-2: -Physical barrier Moreover, components that are secreted by the skin or mucosa, such as sweat, saliva, tears, mucous, help provide a basic barrier against invading pathogens.

Detailed explanation-3: -The first line of defence is non-specific and aims to stop microbes from entering the body. The skin and mucous membranes act as a physical barrier preventing penetration by microbes. If the skin is cut then the blood produces a clot which seals the wound and prevents microbes from entering.