Paper 1: Topic 3 Infection & response - Fighting disease (IV form) Flashcards
Describe what a single-blind trial is
The patient doesn’t know if they are being given a drug or a placebo but the doctor knows what the patient takes
Explain why not all bacterial disease can be treated with penicillin
Different antibiotics kill different types of bacteria It is important medical professionals prescribe the correct antibiotic
Describe what is a placebo
Placebos are tablets/capsules that look identical to the new drug but contain no active ingredient i.e. they are a dummy tablet with no actual drug in them
Name a disease that has been eradicated completely due to vaccination
Smallpox
Explain why is it important that drugs test & trial results are peer reviewed before they are published?
To prevent false claims
Explain 2 ways that the hairs and mucus in the nasal passages act as a non-specific line of defence for the body
- The mucus traps the pathogens (any type hence non-specific response)
- The cilia then beat to waft the mucus to the top of the throat
- where it can be coughed out or swallowed
- and therefore prevent the entry of the pathogen to the lungs
Describe the importance of the discovery of antibiotics
The discovery of antibiotics has led to a significant reduction in communicable diseases
Explain why viral infections are harder to treat
The virus lives inside host cells Hence it is hidden from the immune system This prevents the lymphocytes and phagocytes from identifying and destroying the virus
Describe what the purpose is of a phase 2 of a clinical trial
To determine the effectiveness of the drug
Explain what antibodies are
Specialised proteins that bind to antigens on the surface of a pathogen
Describe what happens in phase 3 of a clinical trial
This will involve thousands of people It will include people with the disease The volunteers will be randomised The effects of the drug will be compared with established drugs
Describe the term ‘peer review’
When scientists who have not been involved in the drug trail in anyway check that the work has been carried out rigorously and the results are valid
State 2 disadvantages of vaccinations
Vaccines do not always work - some people do not produce the antibodies and develop immunity to the pathogen Some people experience side effects to the chemicals in the vaccine e.g. swelling, fever
State the 3 main stages of a drug test
1 Testing on human cells and tissues 2 Testing on live animals 3 Testing on human volunteers
Describe what happens in phase 2 of a clinical trial
The drug is tested on ~200 people This phase will involve the use of a placebo It can involve blind trials and double-blind trials This is used to determine the optimal dose of the drug
Describe phagocytosis
White blood cells engulf the pathogen The white blood cell then breaks down the pathogen
Explain what is meant by the ‘efficacy of the drug’?
How well the drug works to kill the pathogen or relieve the symptoms
What is the optimal dose for any drug?
The dose that has the best effect with minimal (preferably no) side effects
Who discovered penicillin?
Alexander Flemming
Describe how antitoxins help fight pathogens
Antitoxins counteract the toxins produced by the invading bacteria
Explain 2 ways that the skin acts as a non-specific line of defence for the body
The skin forms a barrier to prevent the entry of pathogens The skin secretes antimicrobial chemicals which kill pathogens
Describe what a double-blind trial is
Some patients are given a placebo and some get the new drug but neither the patient or the doctor knows what the patient takes until the trial is complete
Give 2 examples of medicinal drugs that have been obtained from plants. For each example state where it has been discovered
Aspirin - found in willow Digitalis - found in foxgloves
Explain what is meant by the ‘toxicity of the drug’?
Whether or not the drugs might cause harm to cells and tissues of the patient
Explain where antibiotics are obtained from
Many antibiotics are produced by moulds e.g. Penicillin
Why are dead or inactive pathogens used in vaccination?
If the actual pathogen was injected it would cause the disease By injecting dead or inactive pathogens the antigens are still present and therefore stimulate the B-lymphocytes to produce antibodies The dead or inactive pathogens are harmless