diseases

The Invaders
We often say that 'germs' cause diseases. What do we mean by this?

We mean that microbes invade our bodies and cause damage. The commonest types of microbes
are bacteria and viruses.

Other microbes that rarely cause damage include some microscopic parasites and fungi.

Bacteria
Bacteria are fairly…

How does the body fight back?
Passive Protection

Passive defences are those that are set up to stop bacteria or viruses entering the body. They act as
roadblocks. They are found in those places where the invaders are most likely to try to the body.

Invaders try to get inside…