Topic 3 Communicable disease + Flashcards
What are pathogens
Micro organisms that enter the body to cause disease
Definition of communicable disease
Can easily be passed on from one organism to another
What can be infected by pathogens
Plants and animals
How small are bacteria
They are very small cells
They are 1/100th The size of your body cells
Reproduce rapidly inside your body
How does bacteria make you feel ill
By producing toxins that damage your cells and tissues
Are viruses cells
No
How small are viruses
Tiny
1/100th The size of a bacterium
Can viruses reproduce rapidly in the body
Yes
How does viruses spread in the body
Live inside your cells and replicate themselves using the cells machinery to produce copies of themselves
The cell usually burst releasing all the new viruses
How do viruses cause you to feel ill
 The damage that they do to the cells
What are all protists
They are all eukaryotes and most of them are single celled
What are some protists
Parasite
What do parasites do
Live on or inside another organism and cause them damage
What are parasites often transferred to the organism by
Buy a vector which doesn’t get the disease itself e.g. insects
What shapes are fungi
Some fungi are single celled
Others have a body which is made up of a hyphae (thread like structures)
What can Hyphae do
Grow and penetrate human skin and the surface of a plant causing disease
And produce spores which can be spread to other plants and animals
How can pathogens be spread
Water
air
direct contact
How does water spread pathogens
Drinking or bathing in dirty water
E.g. cholera is a bacterial infection that spread by drinking contaminated water
How does air spread pathogens
Pathogens can be carried in the air and then be breathed in
Airborne pathogen is are carried in the air in droplets produced when you cough or sneeze
E.g. influenza virus that causes flu spread this way
How does direct contact spread pathogens
Can we picked up by touching contaminated surfaces including skin
E.g. athletes foot is a fungus which makes skin itch and flake off
the most commonly spread by touching the same things as an infected person e.g. shower floors and towels