Topic 3 - Infection and Die Flashcards
What are pathogens?
Microorganisms that can cause disease
What are the name of diseases that can be spread?
Communicable
How do pathogens spread?
Air
Constipated food and water
Direct contact
How do you stop pathogens spreading?
Hygiene
Kill the vectors
Vaccination
Isolate or quarantine
What are the four types of pathogens?
Virus
Bacteria
Protists
Fungi
What’s are viruses?
Viruses are dead and cannot reproduce by themselves
How do viruses reproduce?
They can reproduce inside a cell by creating copies of themselves
Why do viruses make us feel ill?
Due to the damage of cells when the colonise the body
What is measles and how is it spread?
Causes red rash on body, fever and can be spread by droplets when someone coughs or sneezes
What is HIV and how is it spread?
Causes a deficient immune system to an extent where unusual infections can be easily caught, shared by sexual contact or exchanging of bodily fluids
What is TMV and how is it spread?
Tobacco mosaic virus is a widespread plant pathogen. It will give a distinct mosaic pattern of discolouration which effects the growth of the plant due to lack of photosynthesis
What is a bacterial disease?
Diseases that reproduce rapidly in our cells and release toxins that causes damage to our cells
What is salmonella and how is it spread?
Causes food poisoning, fever, vomiting. Spread by ingesting unhygienic food or poultry that contracted the bacteria.
Poultry in the uk are vaccinated
What is gonorrhoea and how is it spread?
Std that spread from sexual contact. Causes pain urinating and thick yellow discharge
What is fungi?
Eukaryotic organisms that can be unicellular or multicellular
Multicellular fungi can cause disease and spores
What is rose black spot and how is it spread?
A fungal disease that causes black spots on leaves, causing them to drop off and limiting photosynthesis
Can be treated with fungicides
Spreads by wind or rain
What are protists?
They’re eukaryotic cells and some can be parasites which live on or inside another organism
How can a parasite be spread?
By a vector, an organism that carries the parasite but doesn’t get infected
What is malaria and how is it spread?
Causes fever and can be fatal, spread by mosquitoes
How can you stop the spread of malaria?
Kill the vectors
Insecticides or repellents
How is skin part of the defence system?
It is a physical barrier and it secrete oils which have antiobicrobil substances
How is nose part of defence system?
Has lots of little hairs and mucus to stop to trap pathogens
How is the trachea or oesophagus part of the defence system?
Trachea is covered mucus which will trap particles and the cilia move the mucus up into throat to swallow
Stomach has hydrochloric acid so it kills pathogens
What js the most important part of the immune system?
White blood cells which constantly patrol the body
What are the three main functions of white blood cells?
Phagocytosis - white blood cells engulf pathogens
Anti toxins - small molecules that can counteract toxins produced by pathogens
Anti bodies - small proteins that destroy pathogens - creates immunity
How do vaccines work?
Vaccines give weakened or inactivated pathogens to a person to stimulate the white blood cell to produce antibodies and immunity to that pathogen
What are some pros of vaccines?
Protection from diseases
Control of common disease
Preventing outbreaks
What is herd immunity?
Unvaccinated people are unlikely to catch disease because the people around them are vaccinated and the pathogens is killed before it spreads
What are the cons of vaccines?
Don’t always work
Bad reactions to vaccine
What’s are painkillers?
Medicines used tote treat or relieve the symptoms of disease but don’t kill he pathogens
What are antibiotics?
Used to directly kill bacteria and stop them growing, they cannot kill viral pathogens - viruses
What do antibiotics do?
Specific bacteria are killed by specific antibiotics, they can greatly reduce death from bacterial diseases.
Why can’t antibiotics kill viruses?
Antibiotics won’t be able to find them as they hide in cells so drugs may damage cells
They are very different from bacteria and antibiotics are designed to kill bacteria
Where does digitalis come from and what does it do?
It originates from foxgloves and it used to treat the heart
Where do drugs traditionally come from?
Plants and microorganisms
Where is aspirin form and what does it do?
Originates from willow bark and it is a painkiller
Where is penicillin from and what is it used for?
Discovered by Alexander Fleming from penicillium mould - fungus - antibiotic
What are the three things that drugs are tested for?
Toxicity, efficacy, dose
What is efficacy?
How well a drug works and how quickly it works and produces the desired effect
What is toxicity?
How harmful the drug is and what side effects it causes
What is stage 1 of drug testing?
On cells, tissues to test substances but it doesn’t tell us the effects on an entire organism
What is stage 2 of drug testing?
Still preclinical trials, tests live animals such as mice and rabbits - mammals, gives idea on efficacy and toxicity
What is stage 3 of drug testing?
Clinical testing, drug is given to humans
Giving drug to healthy volunteers in low dose
Increase dose to find maximum dose before side effects
What happens after stage 3 of testing?
Drug is given to people with the illness, slowly increasing dose to find max efficacy and min toxicity.
What is a blind test?
Uses a placebo - like the real drug but doesn’t do anything.
It is blind as they patients don’t know what there are taking
What is the purpose of blind testing?
Avoid bias. E.g, more side effects noticed in people that have taken drug
Why is drug testing peer - reviewed?
Analysed by other scientists to check for false results
