Topic 3//Fighting disease/Vaccination/Drugs/Developing drugs Flashcards
What 6 things in human defence system prevent pathogens entering body
Skin
Hairs/Mucus
Trachea/Bronchi
Stomach
how does skin prevent pathogens entering body
skin acts as a barrier to pathogens and secretes antimicrobial substances which kill pathogens
how does hairs and mucus prevent pathogens entering body
Hairs and mucus in your nose trap particles that could contain pathogens
how does the trachea and bronchi prevent pathogens entering body
trachea and bronchi are lined with cilia which is hair like structure which waft the mucus up to the back of the throat where it can be swallowed
how does the stomach prevent pathogens entering body
produces HCL which kills pathogen to make it that far from mouth
What happens if pathogens make it into your body and passes your defence system
Your white blood cells from your immune system which travel around in your blood and crawl into every part of you constantly patrolling for microbes. When they come across invading microbes, they have 3 lines of attack
What is the 1st line of attack for white blood cells
Consuming them:
White blood cells can engulf foreign cells and digest them which is called phagocytosis
What is the 2nd line of attack for white blood cells
Producing antibodies:
every invading pathogen has unique molecules called antigens on it surface. when white blood cells come across foreign antigen, the white blood cells produce proteins called antibodies to bind onto the antigen on the pathogen so they can be found and destroyed by other white blood cells. The antibodies produced are specific to that type of antigen. Antibodies are then produced rapidly and carries around body to find all similar bacteria or virus. The person is naturally immune to that pathogen and wont get ill
what is the 3rd line of attack for white blood cells
Producing antitoxins:
Counteract any toxins produced
How does vaccinations work
involves injecting small amount of dead or inactive pathogens which carry antigens which causes your body to produce antibodies to attack pathogens
What happens if a person is infected with the same pathogen again
The white blood cells will rapidly produce the antibodies to kill it because the person is naturally immune to that pathogen and wont get ill
How does immunisation work
When vaccinated, you are injected with dead or inactive pathogens which have antigens on them. once the Lymphocytes detect a foreign antigen, white blood cells produce antibodies which fight and kill the pathogens.
What is active immunity
the immunity which results from the production of antibodies
What are 2 pros of vaccines
- Has helped control lots of communicable diseases
- Big outbreaks of diseases called epidemics can be prevented if majority population is vaccinated
What are 2 cons of vaccines
- Dont always work sometimes dont give you immunity
- you can sometimes have bad reactions to vaccines
What are painkillers
drugs that relieve pain
Why arent Pain killers used to cure a problem
They actually dont tackle the cause of the disease or kill pathogens they just help relieve symptoms
What does antibiotics do
different types of antibiotics kill different types of bacteria causing the problem without killing your own body cells
Why do doctors not give antibiotics to patients with minor infections
To prevent resistant bacteria developing
Why do antibiotics not destroy viruses
Viruses reproduce using your own body cells which makes it very difficult to develop drugs that destroy only the virus without killing body cells
how does bacteria cause disease once entering body
By producing toxins which damage the host cells and cause diseases
Name a type of medicine that kills bacteria inside your body
Antibiotics
How are antibiotics efficient
Has greatly reduced the number of deaths from communicable diseases caused by bacteria
How can bacteria become resistant to antibiotics
By bacteria mutating, they become resistant to an antibiotic
How can a resistant strain cause a serious infection that cannot be treated by antibiotics
when you have an infection, some bacteria might be resistant to antibiotics so only non-resistant bacteria will get killed. The resistant bacteria will survive and reproduce and population of resistant bacteria will increase. Then the resistant strain could cause serious infection that cannot be treated by antibiotics
How do you slow down the rate of development of resistant strains
Doctors have to avoid over prescribing antibiotics so you wont get them for a sore throat only something serious
Why do most drugs come from plants
Plants produce a variety of chemicals to defend themselves against pests and pathogens which can be used as drugs to treat human disease and relieve symptoms
What are the three main stages in drug preclinical testing
- Drugs are tested on human cells and tissues in the lab
- Test drugs on live animals to test the success of the drug and find out its toxicity and find best dosage
- If passes test on animal, its tested on human volunteers
