Microorganisms, Defence Against Disease Flashcards
Spontaneous generation theory
The thought that the microorganism appeared spontaneously from non living materials
Disproving the spontaneous generation theory
Pasteur’s famous swan neck experiments disproved this theory as they showed that “spoilage” only happened if the nutrient broth was left exposed to the air
Swan neck experiment
He used nutrient broth that had been sterilised through the boiling in a flask. He covered the openings of some flasks, left some open and to other flasks he introduced a swan neck bend and left them uncovered.
Swan neck results
The results prove that spoilage only happens if the microbes can gain access to the broth. We now understand that the nutrients in the broth are needed to provide the energy and materials required for cell division of bacteria
Pasteurisation
This involves heating foods to temperatures (but NOT boiling) and then chilling rapidly.
This techniques kills most bacteria that would otherwise result in food spoiling or unusable
Virus’
>HIV(AIDS) > rubella >measles >mumps >colds and flu > polio
Bacteriums
> salmonella
gonorrhoea
tuberculosis
chlamydia
Fungus
> athletes foot
HIV
Spread
Exchange of body fluid during sex or infected blood
Control/prevention/treatment
Using a condom reduces risk of infection
Drug addicts no sharing needles
NO CURE
Rubella
Spread Air born ( droplet inflection) through coughing and sneezing
Control/prevention/treatment
Prevented by MMR vaccination
Measles
Spread Air born (droplet infection) through coughing or sneezing or by contact
Control/prevention/treatment
Prevented by MMR vaccination
Mumps
Spread Air born (droplets infection) through coughing and sneezing
Control/prevention/treatment
Prevented by MMR vaccination
Cold and flus
Spread Air born (droplet infection) through coughing and sneezing
Control/prevention/treatment
Flu vaccination for targeted groups
Polio
Spread
Usually spread through drinking water contaminated with faeces
Control/prevention/treatment
Polio vaccination currently eradicated polio in the uk
Salmonella
Spread
Food contamination
Control/prevention/treatment
Food cooked thoroughly and not mixing cooked and uncooked foods can control spread
Antibiotics
Gonorrhoea
Spread
Sexual contact
Control/prevention/treatment
Condom reduces risk of infection
Antibiotics
Tuberculosis
Spread Air born (water droplets) through coughing and sneezing
Control/prevention/treatment
BCG vaccination.
If contacted treated with drugs and antibiotics
Chlamydia
Spread
Sexual contact
Control/prevention/treatment
Condoms reduce risk of infection
Antibiotics
Athletes foot
Spread
Contact
Control/prevention/treatment
Avoid direct contact in area where spores are likely to be present
Flip flops in changing rooms and around pool
Non-specific defences to diseases
>lungs >eyes >hair >stomach >cuts >skin
Lungs (defence)
Cells produce mucus which traps dust and germs. Cilla moves the mucus upwards
Eyes (defence)
Tear glands make an antiseptic fluid which kills germs
Hair (defence)
Follicles- glands in the skin make an antiseptic oil
Stomach (defence)
Acid made by lining of the stomach kills germs
Cuts (defence)
When cut the blood forms a clot which develops a scab to prevent entry of bacteria
Skin (defence)
Dead outer layer of skin forms a barrier
Why does your blood clot?
If skin is broken at any point there is a chance that pathogens could enter
How does the blood clot?
When cut, platelets in bloodstream come into contact with the air. They rupture releasing chemicals that cause a protein fibrinogen to become insoluble protein fibrin.
This forms a mesh of fibres over the wound and cause more to rupture. They become sticky and become a platelet plug.
What does blood clotting prevent?
> blood loss
>pathogens entering the bloodstream
what is the immune sexy stem responsible for?
It deals with any pathogens that breach the physical barriers and will enter the body causing an infection
What deals with pathogens (foreign invaders)?
White blood cells
Phagocytes
White blood cells capable of detecting, ingesting and digesting foreign cells- known as PHAGOCYTES
they have loved uncles and can change shape
Phagocytosis (stages)
- Digestion
- Migration- the phagocytes changes shape and moves towards the bacteria
- Bacteria becomes engulfed
- Digestion- bacteria are digested by enzymes
The role of lymphocytes
> to recognise and label non-self (foreign) molecules
>produce antibodies following exposure to these foreign molecules