Pathogens and fighting infections

Pathogens are microorganisms that cause infectious diseases.

There are two main types of pathogens: bacteria and viruses. Bacteria are very small living cells which reproduce very quickly. They make you feel bad because they damage your body cells and they produce toxins.

Viruses are a bit different. They are not living cells because they do not carry out any living processes. That's one reason why antibiotics can't kill viruses but I will talk about it some other time.

How do viruses attack body cells?
When a virus enters the cell, it releases the nuclei acid which gets to the nucleus of your cell. It uses it to replicate itself by changing the way the cell used to work. So now, the cell is ignoring its own needs and responsibilities and is focused only on producing new viruses. Eventually, the cell will burst releasing all new viruses, so they can invade other cells.

Fighting infections

 Your body helps you to fight with pathogens. It does it by:

• acid in your stomach kills some microorganisms
• tears protect eyes from microorganisms
• skin is a natural body cover
• mucus stops pathogens entering.

If you cut yourself, platelets (fragments of cells) will help to seal the wound stopping pathogens entering the body.

 White blood cells produce antibodies and pathogens have antigens. When pathogen enters the body, the white blood cell start producing specific antibodies to kill that particular pathogen. They attach to antigens.

White blood cells can also consume the pathogen and digest it or it can produce antitoxins.