B2 - Keeping Healthy Flashcards
What are infections caused by?
Microorganisms damaging body cells or producing poisons (toxins) that harm cells.
What can infections be treated by?
Drugs called antimicrobials (e.g. antibiotics)
True or False?
All antimicrobials kill microorganisms.
False - Many antimicrobials kill the microorganisms but some just block or slow down their action.
Many antimicrobials kill the microorganisms but some just block or slow down their action.
What is this called? (HT)
Inhibition.
What are 3 types of microorganisms that cause infections? Give examples of each and state how each type can be treated.
- Bacteria, e.g. bubonic plague, tuberculosis (TB) and cystitis. treated by antibiotics.
- Fungi, e.g. athlete’s foot, thrush and ringworm. Treated by anti-fungal medicine and antibiotics.
- Viruses, e.g. Asian bird flu, common cold, HIV, measles and smallpox. Very difficult to treat as antibiotics don’t work on viruses
Where can microorganisms be found?
On any surface, in food and drink, in water and in the air we breathe.
What three conditions are ideally needed for microorganisms to grow rapidly?
- Warmth
- Plenty of nutrients
- Lots of moisture
Fill in the gaps.
Once in your body, harmful microorganisms reproduce very _______ - some populations can double as fast as every _______ minutes.
- rapidly
- 20
Symptoms of an illness only show when there’s a significant amount of infection. How are the symptoms caused?
By microorganisms damaging infected cells, e.g. bursting the cells or producing harmful toxins.
If microorganisms get into your body, what is activated?
The immune system
When microorganisms get into your body and the immune system is activated, what type of blood cell plays a major role in the body’s response?
The white blood cell
Two types of white blood cells are released when the body’s immune system is activated. What do the two types of white blood cells do?
One type of white blood cell engulfs and destroys the microorganisms, and the other makes antibodies.
How does a white blood cell digest microorganisms?
When microorganisms invade the body, the white blood cells find them and engulf them. They then ingest the micro-organism and digest and destroy them.
What are antigens?
Markers on the surface of the microorganism.
What happens when white blood cell are producing antibodies?
The white blood cells become sensitised to the antigens on the surface of the microorganism and produces antibodies that lock onto the specific shape of the microorganism’s antigens. This causes the microorganisms to clump together, so that other white blood cells can digest them.
Why do microorganisms have uniquely-shaped antigens on their surface?
Because different microorganisms cause different diseases.
How does the process of producing antibodies help the body’s immune system?
Some white blood cells act as ‘memory cells’ once the infection has been destroyed, so that when those microorganisms enter the body again, the immune system knows how to fight it off. This is natural immunity.
What happens when an individual is vaccinated?
A weakened/dead strain of the microorganism is injected into the system. White blood cells produce the antibodies to fight it off and the memory cells know how to fight that type of microorganism off when the real version enters the system.
True or False?
Vaccinations are completely safe all the time.
False - Vaccinations are never completely safe and can produce minor side effects, such as rashes. Extreme side effects are rare, but the vaccination usually carries less risk than the disease.
Why might some people be more affected by a vaccination than others?
Because of genetic variation.
Why do some vaccines have to be redeveloped regularly?
Because microorganisms mutate (randomly genetically change) to produce new varieties/strains.
True or False?
The more who say no to having a vaccination, the smaller the chance of a disease outbreak and a slower spread of disease.
False - The more who say no to having a vaccination, the more likely it is that there will be a disease epidemic/outbreak and the faster it will spread.
Why is it important to vaccinate as many people as possible? (HT)
Because it prevents a disease epidemic
What will happen to a population of which more than 95% are vaccinated against a disease?
The unvaccinated will be protected as well, as the risk of contact with an infected person is small.
What will happen to a population of which less that 95% are vaccinated against a disease?
There is a greater chance of contact with infected people and therefore the likelihood of a disease outbreak/epidemic is much higher.
Over time, bacteria and fungi can become _________ to antimicrobials.
Resistant.
When random mutations occur in genes of microorganisms, what can happen? (2 things) (HT)
- New strains develop
- These are less affected by antimicrobials, so they can reproduce and pass on their resistance.
Complete the sentence.
As varieties of bacteria and fungi become resistant…
…there are fewer ways to defeat them.
What two measures can be put in place to help prevent antimicrobial resistance?
- Doctors should only prescribe them when absolutely completely necessary
- Patients should always complete the course of medication prescribed to them.
What are new drugs tested for before they can be used?
Safety and effectiveness
What are some advantages of testing on human cells grown in a laboratory?
- Shows if the drugs are effective
- Shows if the drugs will damage cells
- No people or animals are harmed
What are some disadvantages of testing on human cells grown in a laboratory?
- Doesn’t show the effects on the whole organism
- Some might say that growing human cells is wrong/unethical
What are some advantages of testing on animals in a laboratory?
- Shows if the drugs are effective within whole body conditions
- Shows if drugs are safe for the whole body
What are some disadvantages of testing on animals in a laboratory?
- Animals can suffer and die (unethical issues)
- Animals may react differently to humans
Who are clinical trials carried out on?
- Healthy volunteers to test for safety
- People with the illness to test for safety and effectiveness
What is a placebo?
A harmless drug
What does using a placebo in a clinical trial mean?
The patient isn’t treated for the problem - you haven’t got any false reactions.
What do clinical trials compare the effects of? (HT)
Old and new drugs