Pathogens

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…