Topic 5-Microorganisms and disease Flashcards
What are pathogens?
A disease-causing microorganism
How do the skin stop microbes getting into the body?
A layer of dead cells form a barrier on the body.
There is also a community of microbes on the skin, that makes it difficult for pathogens to come established on the skin surface.
How the platelets defend against infection?
Platelets clot the blood in a cut and form a scab
How do white blood cells defend against microbes that are inside the body?
Phagocytes engulf bacteria
Lymphocytes produces antibodies to inactivate bacteria or virus
Lymphocytes produce antitoxins the counteract toxins released by bacteria
What is an antibody?
Binds to antigen and destroys the foreign cell
What is an antigen?
A molecule on the cell surface that can be recognised by the immune system
During an immune response, what are the steps of the primary response?
1- lymphocyte recognises foreign antigen
2-clones differentiate. Most developed short lived plasma cells.
3- plasma cells produce antibodies that will destroy the cells carry on the specific for an antigen.
4 – symptoms develop into long lasting memory cells
During an immune response, what are the steps of the secondary response?
1- memory cells a long lasting and if they come across the specific antigen again they stimulate and immune response.
2- large numbers of plasma cells develop producing a large concentration of antibodies very quickly.
3-More memory cells produced. This boosts immunity.
Explain the difference between primary and secondary response
The primary response is slower than the secondary response
The concentration of antibodies produced in secondary response is higher than the primary response.
The concentration of antibodies stay much longer in the secondary response compared to the primary response
Why do people suffer from the flu more than once?
It mutates rapidly giving rise to new strains with different antigens
Describe how edward jenner used a vaccination against smallpox
He Hered that milkmaids who suffered from cowpox never suffered from smallpox.
He suggested that the purse in the blisters the milkmaids received from the cowpox protect them from smallpox.
In 1796 he inoculated a healthy boy with pus taken from a cowpox spot.
A few weeks later he inoculated the boy again this time with smallpox.
His theory was proved correct because the boy survived
What is a vaccination?
Where you are injected with a small amount pf dead or inactive pathogens into the body
What is an antibiotic?
A substance produced by a microorganism to kill other microorganisms
What is resistance?
The ability of an organism to survive exposure to a dose of poison that would normally kill it
What methods prevent the spreading of MRSA in hospitals?
Hand washing
Cleaning
Alcohol gels
MRSA screening before surgery
