Term
| What is bigger, a virus or bacteria? |
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Definition
| Viruses are smaller than bacteria |
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Term
| What do we call micro-organisms that cause disease? |
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Definition
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Term
| How do bacteria make you feel ill? |
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Definition
| They reproduce inside your body and produce toxins (poisons). The toxins move around your body in blood and these toxins make you feel ill. |
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Term
| How do viruses make you feel ill? |
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Definition
| Viruses reproduce inside your cells. When they have reproduced they burst out of the cell, completely destroying the cell. This cell damage makes you feel ill. |
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Term
| How do viruses make you feel ill? |
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Definition
| Viruses reproduce inside your cells. When they have reproduced they burst out of the cell, completely destroying the cell. This cell damage makes you feel ill. |
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Term
| How do viruses make you feel ill? |
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Definition
| Viruses reproduce inside your cells. When they have reproduced they burst out of the cell, completely destroying the cell. This cell damage makes you feel ill. |
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Term
| What was the problem in the hospital that Semmelweiss worked in and what did he do about it? |
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Definition
Many people were dying, including women who came in to give birth and were not ill.
Semmelweiss thought the doctors must have something on their hands that spread disease from ill people to healthy people so he made doctors wash their hands in chlorine water before examining the pregnant women. |
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Term
| Why did people not believe Semmelweiss and not wash their hands? |
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Definition
| Micro-organisms had never been seen and people did not believe that doctors could be unclean and spread infection by something that could not be seen. They did not believe it even though death rates dramatically dropped after he introduced hand-washing. |
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Term
| How was Semmelweiss’ work important? |
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Definition
| After Pasteur discovered micro-organisms people realised that Semmelweiss’ theory was correct. Handwashing is now a very important part of hospital hygiene. |
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Term
| What are the three ways that white blood cells as part of your immune system? |
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Definition
1) by ingesting pathogens
2) by producing antibodies which destroy particular bacteria or viruses
3) by producing antitoxins which counteract the toxins (poisons) released by pathogens. |
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Term
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Definition
| When a lot of people in a country have a disease at the same time. |
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Term
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Definition
| When an epidemic spreads worldwide |
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Term
| How do antibodies destroy pathogens? |
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Definition
| Antibodies are produced by white blood cells. There are many different antibodies and each has a specific structure. This means different antibodies are specific to different pathogens. Antibodies group round pathogens and bind to antigens (on the surface of pathogens) and kill them directly or once clumped they are ingested by other white blood cells. |
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Term
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Definition
| Relieve the symptoms of infectious disease. They do not kill the pathogens. |
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Term
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Definition
| They help to cure bacterial disease by killing infective disease inside the body. They cannot kill viruses. |
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Term
| Why is it difficult to produce good antiviral drugs to kill viruses? |
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Definition
| Because viruses reproduce inside your cells it is difficult to develop drugs which kill viruses without also damaging the body’s tissues. |
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Term
| Many antibiotics are originally found naturally, e.g. from fungi. Why is it better to then make the substance chemically rather than extracting it from fungi? |
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Definition
| Because if you make it chemically you can guarantee that is pure and you can easily control the strength. |
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Term
| Why should doctors not prescribe antibiotics too often? |
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Definition
| Because antibiotic resistance can develop. |
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Term
| How does antibiotic resistant bacteria, such as MRSA develop? |
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Definition
| As a result of natural selection. Some bacteria are naturally resistant to antibiotics. These few bacteria are not killed when an antibiotic is used. They can then grow without any competitors. More bacteria will grow and will not be killed if the antibiotic is given again. |
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Term
| New diseases are developing. Why do people worry about new diseases, such as SARS and bird flu? |
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Definition
| Because they can spread quickly and people do not know what the effects can be. Doctors do not know how best to treat the new diseases and vaccinations are not available. |
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Term
| How do new diseases develop? |
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Definition
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Term
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Definition
| An injection of a small quantity of dead or inactive forms of the pathogen into the body. |
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Term
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Definition
Vaccines stimulate the white blood cells to produce antibodies that destroy the pathogens. The white blood cells produce a different type of antibody to match the specific antigens on specific pathogens. For a new pathogen this can take some time.
The vaccine makes the person immune to future infections by the microorganism, because the body can respond by rapidly making the correct antibody, in the same way as if the person had previously had the disease. |
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Term
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Definition
| The MMR vaccine is used to protect children against measles, mumps and rubella. It is sometimes called the ‘triple vaccine.’ |
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Term
| Why are many people not giving their children the MMR vaccine and what problem is this causing? |
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Definition
| There was a report that the MMR vaccine could cause autism so parents became worried. No scientific evidence has proven any link. Many people are not having the vaccine and so there are now measles epidemics and many children are dying from this disease. |
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