A microbe is anything too small to be seen without a microscope. Microbes are in the water you drink, the food you eat, and the air you breathe - they are everywhere. About 95% are good for us. Microbes and Diseases. These are called PATHOGENS. They include: Viruses Bacteria Fungi
A microbe is anything too small to be seen without a microscope
Microbes are in the water you drink, the food you eat, and the air you breathe -they are everywhere.
About 95% are good for us.
These are called PATHOGENS.
The body’s natural barriers:
These can be caused by cell damage or by toxins (poisons)
A rash Fever Swelling Vomiting DiarrhoeaSYMPTOMS–signs of a disease (illness) not normal
stop the bacteria reproducing
and others kill the bacteria.
The immune system’s job is to kill any organisms that enter the body
White blood cells are always used in fighting off microbes and are responsible for building up immunity to disease.
One type of white blood cell attacks anything that is ‘foreign’ or not meant to be there. It surrounds the microbe and digests (eats)it.White Blood cells defend the body!
Another type of white blood cell attacks only certain microorganisms.
Every pathogen has unique molecules (antigens) on its surface; when white blood cells don’t recognise these antigens, they start to produce antibodies, which lock onto and kill the pathogens.
Once a white blood cell recognises the antigens on a pathogen, it divides quickly to make more antibodies to fight the infection. Some of these cells stay in the blood and ‘remember’ the antigens, so that they can quickly produce lots of antibodies if the body gets infected again – that’s why you are usually immune to most diseases you have had in the past.
It prevents disease
Big outbreaks of a disease (epidemic) can be prevented if many people have been vaccinated
Some diseases have been stopped completelyVaccination – good or bad?
They cannot be completely safe for everyone.
Some people have side effects e.g. painful arm for a short time, high temperatureVaccinations