Communicable diseases Flashcards
What is a communicable disease ?
They are spread from person to person. They are infectious
What are communicable diseases spread by?
Pathogens
What are pathogens?
Microorganisms that cause infectious diseases
What are 4 main pathogens?
Viruses, bacteria, fungi and protists
How do bacteria make us ill ?
Bacteria reproduce very quickly.
They may produce toxins (poisons) that affect your body and make you feel ill.
How do viruses make you ill ?
Viruses cannot reproduce themselves .
First the virus invades the host cell. Then the virus reproduces inside the host cell when the virus leaves it can cause the cell to burst open.
What’s bigger bacteria or viruses ?
Bacteria
What are The 4 main ways pathogens spread?
By air
Through direct contact
By water
By vectors e.g. mosquitoes
What are 2 examples of pathogens being spread through the air ?
While you talk or if you sneeze
What are 2 examples of how pathogens can spread through direct contact ?
Through sexual contact
Through cuts/blood
What is an example of how pathogens can spread through water ?
Eating/drinking contaminated food/drink
explain process of vaccination
- small quantities of dead or inactive forms of pathogen introduced into body
- this stimulates white blood cells to produce antibodies
- if same pathogen re-enters the body, white blood cells respond quickly to produce same antibodies, preventing infection
What is an antigen?
a toxin or other foreign substance which induces an immune response in the body, especially the production of antibodies.
What happens when the vaccine is put into your body?
The small amount of dead/inactive pathogen stimulates your white blood cells to produce the antibodies needed to fight the pathogen.
What is an advantage of vaccination?
Help to control communicable diseases
What is an disadvantage of vaccination?
Don’t always work and you can have a bad reaction to it
What is antibiotics ?
Antibiotics are medicines that fight infections caused by bacteria in humans and animals by either killing the bacteria or making it difficult for the bacteria to grow
What is Chemotherapy ?
Use of drugs to treat a disease
Examples of antibiotics ?
Penicillin, tetracyclines, polymyxins and sulfa drugs
Name an example of what antibiotics can and can’t kill ?
Can kill bacteria and fungi, but not viruses
How do antibiotics kill ?
Antibiotics work by blocking vital processes in bacteria, killing the bacteria or stopping them from multiplying.
Why an antibiotics not kill viruses?
Antibiotics cannot kill viruses because viruses have different structures and replicate in a different way than bacteria.
Why must new medical drugs be tested before being used?
To check that they are safe for everyone
What 3 things are new drugs tested for?
Toxicity
Efficacy - how well they do their job
Dosage
How long can it take for a new medicine to be tested and reach your doctors surgery?
12 years
Give 3 examples of things used to carry out preclinical tests on.
Cells
Tissues
Live animals
Where are preclinical tests carried out?
In labs
Who are involved in clinical trials?
Healthy volunteers and patients
Why are clinical trials kept small to start with and patients are only given small dosage?
This is the first time when you test for side effects, so originally there could be some health risks
What is a double blind trial
A blind trial is where people don’t know which treatment they are getting. They could be one of the following: the new treatment. the standard treatment.
What is a blind trial ?
Where the patient doesn’t know if he’s getting real drug or fake one but the doctor knows.
What is a placebo?
A replica of the real drug but the placebo is a fake one that has no effect
What are 4 stages of drug development ?
- Discovery and Development - Research for a new drug
- Preclinical Research - Tested on animals like mouse
- Clinical Research - tested on people to make sure they are safe
- Review the drug - Check they are safe for everyone and if they will release or not
