Zusammenfassung der Ressource
1.1 Pathogens
- Micro-organisms that cause
disease, e.g.viruses and
bacteria
- A microorganism is a single celled
organism too small to be seen
without a microscope
- Disease is a description of certain symptoms - physical or
mental. It suggests a malfunction of body or mind which
has an adverse affect on good health
- For a microorganism
to be considered 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
- How pathogens enter the
body:
- the gas
exchange
system
- The digestive
system
- The Body's defences against
pathogens:
- mucous layer that covers exchange surfaces and
forms a sticky, hard to penetrate barrier
- the production of enzymes that
break down pathogens
- production of stomach acid that kills
microorganisms
- How pathogens cause disease
- By damaging host tissues
- by producing toxins