Answer:
The body’s first line of defence
•Skin
The skin is the largest organ of your body. It acts as a barrier between invaders (pathogens) and your body. Skin forms a waterproof mechanical barrier. Microorganisms that live all over your skin can’t get through your skin unless it’s broken.
•Tears, mucus and saliva
Your nose, mouth and eyes are obvious entry points for pathogens. However, tears, mucus and saliva contain an enzyme that breaks down the cell wall of many bacteria. Those that are not killed immediately are trapped in mucus and swallowed. Special cells line and protect the nose, throat and other passages within your body. The inner lining of your gut and lungs also produces mucus to trap invading pathogens.
•Cilia
Very fine hairs (cilia) lining your windpipe move mucus and trapped particles away from your lungs. Particles can be bacteria or material such as dust or smoke.
•Stomach acid
Stomach acid kills bacteria and parasites that have been swallowed.
•Urine flow
Your urine flow flushes out pathogens from the bladder area.
