- Pathogens are disease causing microorganisms, that our body has many defence mechanisms against.
- The skin is the first physical barrier, providing a protective layer that is hard to penetrate. We also have sebaceous glands that secrete acids, thus preventing the growth of pathogens.
- Pathogens can enter through our mouth, nose and eyes quite easily. Saliva, mucus and tears contain lysozyme enzymes that break down the cell wall of many bacteria.
- Our respiratory system then has it’s own defenses from nasal hair to mucus to enzymes.
- Hydrochloric acid inside our stomach kills many harmful microorganisms that enter in our food and drink.
Our blood also has a great defense system; blood contains platelets and fibrin which causes blood to clot and scabs to form, sealing off cuts from the outside. Our blood also has another fantastic weapon; white blood cells. These can hunt down and destroy pathogens, they can ingest them, and they can neutralise the effect of the pathogen toxins on the body.