Microorganisms = small and single celled.
Examples include... Bacteria and viruses - many live in our bodies and are beneficial to us.
But some are harmful and cause disease - these are PATHOGENS.
WHAT IS DISEASE?
- A description of certain symptoms (physical or mental) or both; it suggests a malfunction of body or mind (having an adverse effect on good health). It has mental, physical and social aspects.
MICROORGANISMS AS PATHOGENS.
In order for a microorganism to be considered as a pathogen, it must:
- Gain entry to the host
- Colonise the tissues of the host
- Resist the defences of the host
- Cause damage to the host tissues
Examples of Pathogens = BACERIA, VIRUSES, & FUNGI.
An infection occurs when a pathogen gains entry to the host and colonises its tissue.
DISEASE occurs when an INFECTION leads to symptoms in the host.
TRANSMISSION = when a pathogen is transferred from one person to another.
HOW DO MICROORGANISMS GET INTO THE BODY?
- usually by penetrating interfaces with…