bodys defence system

• the skin acts as a barrier to pathogens, it also secretes anti-microbial substances which kill pathogens
• hairs a mucus in your nose trap dust and other particles and prevent them from entering your lungs
• the trachea and bronchi secrete mucus to trap pathogens
• also the trachea and bronchi are lined with cilla - these hair-like substances which waft the mucus up to the back of the throat where it can be swallowed
• the stomach produces hydrochloric acid that kills pathogens