Your body is under constant attack from viruses and bacteria, but you have a complex defence system which kills foreign invaders - your immune system. What is it and how does it work?
- Our bodies are constantly under attack from bacteria and viruses.
- Our immune system provides a defence, seeking out and killing foreign bodies.
- Physical barriers like skin, hairs, mucus and tears all act to keep out foreign bodies.
- The immune system's key workers are white blood cells called phagocytes and lymphocytes.