fighting disease

• body defence system: skin acts as a barrier to pathogens and secretes antimicrobial substances, hair and mucus in nose trap pathogens, trachea and bronchi secrete mucus and are lined with cilia which waft mucus to the back of throat to be swallowed, stomach produces hydrochloric acid which kills bacteria
• phagocytosis: white blood cells engulf and digest foreign cells/pathogens
• lymphocytes: white blood cells produce antibodies specific to antigens on pathogens, antibodies attach to them and destroy them, antibodies produce rapidly and move around body to find similar bacteria - memory cells, people become naturally immune
• antitoxins are produced to counteract toxins produced by invading bacteria