1.1- Pathogens - created from Mind Map

Microorganism is a general term for a single-celled organism that is too small to be seen without a microscope Includes Bacteria and Viruses Some are beneficial to us, some cause harm

A Pathogen is a Microorganism that causes diseaseInclude: Fungi, Viruses and Bacterium

A disease is a description of symptoms which suggests a malfunction of body or mind, and has social, mental and physical aspects.

For a Microorganism to be considered as a Pathogen Gain entry to the host Colonise the tissue of the host Resist the defences of the host Cause damage to host tissues

If a Pathogen gets into the host and colonises its tissue an infection results

Disease occurs when an infection leads to recognisable symptoms in the host

When a Pathogen is transferred from one individual to another it is known as transmission

How do they enter the body? The gas-exchange system, e.g. influenza, tuberculosis and bronchitis The digestive system, (through food and water) e.g. cholera, typhoid, and dysentery pathogens

How do they cause disease? By damaging host tissues- breaking down the cell membrane or a virus inhibits the synthesis of DNA, RNA and proteins By producing toxins- (most bacterial) e.g. cholera bacterium produces a toxin that leads to excesssive water loss from the lining of the intestines

Prevention of entry The production of stomach acid, which kills microorganisms Mucous layer that covers exchange surfaces, thick and sticky, hard to penetrate The production of enzymes that break down pathogens

1.1- Pathogens