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Skin

• Skin acts as a barrier
• It is a tough, dead outer layer
• The sebum on skin repels pathogens
• Scabs form a barrier over cuts

Eye

• Produce tears containing enzymes to kill bacteria
• The tears are also antiseptic

Lungs

• Trachea produces sticky mucus to trap bacteria
• Cilia carries the mucus and bacteria away

Stomach

• Contains hydrochloric acid which kills bacteria </aside>

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How white blood cells destroy pathogens

Phagocytosis: Pathogen is engulfed and digested using enzymes

Antibody Production: Specific antibodies are produced to bind to the antigens on the pathogen. This helps the other white blood cells find the pathogens and destroy them

Antitoxins: They neutralise toxins produced by bacteria

Memory Cells: Give a more rapid response if re-infected with the pathogen

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