Covers almost all parts of your body to prevent infection from pathogens. If it is cut or grazed, it immediately begins to heal itself, often by forming a scab
Made in various places in the body, pathogens get trapped in the mucus and can then be removed from the body (by coughing, blowing the nose, swallowing etc)
Contains hydrochloric acid which is strong enough to kill any pathogens that have been caught in mucus in the airways and then swallowed or have been consumed in food or water
Different types of white blood cell work to prevent pathogens reaching areas of the body they can replicate in
By phagocytosis - engulfing and digesting pathogenic cells
By producing antibodies - which clump pathogenic cells together so they can't move as easily (known as agglutination) and releasing chemicals that signal to other cells that they must be destroyed