B3 Infection And Response Flashcards
Pathogens are…
Microorganisms that enter the body and cause disease. Affect both plants and humans
Bacteria are
Very small cells that rapidly reproduce. They produce toxins that damages cells and tissues.
Viruses are
Not cells, they’re smaller and reproduce rapidly. Live inside cells and replicate themselves using cells mechanisms. Cells burst and the virus spreads and causes cell damage.
Protests are
All eukaryotes and mainly single called. Some are parasites and they live on organisms and cause damage to organisms. They’re transfers to the organism by vectors.
Fungi are
Sometime single called and others have bodies made up of hyphae. These grow and penetrate human skin and plants. They produce spores and spread.
Ways pathogens can spread
Water e.g cholera through contaminated water
Air as pathogens are carried in the air and can be produced through coughs or sneezing
Direct contact e.g athletes foot
Viral diseases examples
Measles spread by droplets from infected sneezes. A red rash and fever happens.
Stopped by vaccination.
HIV is spread by sexual contact or sharing of bodily flood. Flu like symptoms. Controlled with anti removal drugs to stop virus replicating.
Tobacco mosaic virus affects plants like tomatoes. Mosaic pattern on leaves and leaves become discoloured> no photosynthesis
Fungal disease examples
Rose black spot is a fungus that causes purple or blacks spots on leave of rose plants. Leaves go yellow and fall off meaning less photosynthesis. Spread through wind and water. Treated with fungicide and removing affected leaves
Protest disease examples
Malaria is spread by the vector mosquitos. They get the malarial protist when they feed on infected animals. Causes repetitive fever. Spread can be stop by stopping breeding of mosquitos. Use insecticides and mosquito nets
Bacterial diseases examples
Salmonella is a type of bacteria. Causes fever vomiting and diarrhoea. Caused by toxins produced by bacteria. Get it by eating food that has been contaminated with the bacteria. In uk most poultry given a vaccination
Gonorrhoea is a std which causes pain when urinating or a thick yellow discharge. Treated with different antibiotics and prevented with contraception
Preventing diseases
Hygiene. Washing hands etc
Destroying vectors by getting rid of organisms that spread disease. Insecticides or destroying habitats
Isolating infected individuals to prevent the spread
Vaccination means you can develop the infection and stop the spread
Fighting disease with your bodies defence system
Skin acts as a barrier against pathogens and secretes antimicrobial substances to kill pathogens.
Hair and mucus in the nose trap particles that coils contain pathogens.
Trachea and bronchi secrete mucus to trap pathogens. Lined with cilia to waft mucus to throat where is can be swallowed.
Stomach produces hydrochloric acid to kill pathogens
If pathogens gets into the body, the immune system helps
What does the immune system do to kill of pathogens
White blood cells engulf and digest foreign cells.
They then produce antibodies to lock onto invading cells so they can be found and destroyed. Antibodies are specific and produced rapidly. If a person is infected by the same thing again, antibodies are quickly produced to kill off the pathogens(unique molecules on pathogen surface) > naturally immune.
Producing antitoxins which counteract the toxins produced.
Vaccination
Vaccinations inject a small amount of dead or inactive pathogens which carry antigens, so white blood cells can create antibodies. This means if the pathogen comes into the body the antibodies can be produced straight away and kill off the pathogens rather than waiting a few days to produce the anti bodies and then becoming ill.
Pros and cons of vaccination
Pros - controls communicable diseases like small pox and polio
Big outbreaks (epidemics) can be prevented with vaccinations
Cons - don’t always work
Sometimes have a bad reaction like swelling.
