B6 - Preventing and Treating Disease Flashcards
What is an antigen?
A unique protein on the surface of a cell
What type of cell produces antibodies?
White blood cells - Lymphocytes
What does an antibody do?
They join to antigens and destroy the pathogen
How does immunity occur (naturally)?
Upon first encountering a new pathogen, white blood cells need to create new antibodies to destroy them.
Some white blood cells will “remember” how to make these specific antibodies if the same pathogen enters the body.
This allows the WBCs to kill the pathogens quickly, before they can have any effect upon the body, making you immune
What does a vaccine contain?
A dead or inactivated form of a disease-causing microorganism
What does a vaccine do?
It causes immunity through stimulating the WBCs to create antibodies to kill the inactivated pathogen
Now that the WBCs know how to make these antibodies, they can defend against the living version of the pathogen
What types of disease can vaccines protect you against?
Bacterial such as Tetanus and Diphtheria
Viral such as Polio, Measles, and Mumps
Give an example of a disease that has been eradicated through vaccines
Smallpox
What disease do doctors think vaccines can soon eradicate?
Polio
What is herd immunity?
Immunising a large proportion of the population to reduce the spread of a pathogen and so a disease
What would happen if the herd immunity is lost?
The disease would reappear
Give an example of when herd immunity was lost.
1970s UK
There was a scare about the safety of the whooping cough vaccine
Vaccination rates fell from 80% to 30%
In the following years, thousands of children got whooping cough again and many died
People began to use vaccines again so the herd immunity was regained
How does the World Health Organisation want to achieve global herd immunity for measles?
WHO wants 95% of children to have two doses of measles vaccine to give global herd immunity
What are the current statistics of achieving global herd immunity for measles?
85% of children receive the first dose
56% of children receive the second dose
Name two common painkillers
Paracetamol
Aspirin
What can painkillers do?
Relieve headaches and sore throats
Reduce pain
What do painkillers NOT do?
Kill viruses, bacteria or cure the disease
What type of drugs are used to cure bacterial diseases?
Antibiotics
What are antiseptics used for?
Killing bacteria outside the body
Why are antiseptics and disinfectants not used inside the body?
They are very poisonous and they would kill you
When did antibiotics first become widely available?
The 1940s
Who discovered Penicillin and what is Penicillin an example of?
Alexander Fleming
Antibiotics
How do antibiotics work?
They kill the bacterial cells inside your body, without damaging your own cells
Why can antibiotics not be used on viruses?
Viruses invade the human’s cells and reproduce inside them
Antibiotics do not effect a human’s cells and so the viruses are not killed
It is extremely difficult to develop drugs that will kill viruses without damaging the body’s cells at the same time
How do antibiotics enter the body?
Usually through a syrup or a pill
If very ill, they could be put straight into the bloodstream
How do bacteria become resistant to antibiotics?
Evolving / mutating
Where can drugs be extract from?
Plants or microorganisms such as moulds
What two drugs are extracted from foxgloves and what is their purpose?
Digitalis and Digoxin
They have been used since the 18th century to help strengthen the heartbeat
What drug originates from the bark of willow trees?
Aspirin
How was penicillin discovered?
Alexander Fleming was careless and often left the lids off of his culture plates
After one holiday, he noticed mould growing on lots of the plates
He also noticed a clear ring in the jelly around some of the mould.
He realised that something had killed the bacteria
“Penicillin” was named after “Penicillium” (the mould that produced it
