B1.3 Drug abuse Flashcards
What are the main differences between viruses and bacteria?
Bacteria are living cells that produce toxins that damage cells in the body
Viruses invade cells and replicate themselves, they cannot be seen with a microscope
How is the body adapted to fight disease?
Skin as a barrier
Cilia and mucus
Blood clots to seal wounds
White blood cells producing antibodies and anti toxins
How to white blood cells prevent illness?
An invading cell will have unrecognised antigens on its surface
The white blood cell produces new antibodies that are able to fit on these antigens and destroy the pathogen
The white blood cell can now remember this antibody and it is readily available if the pathogen tries to infect the person again.
How do vaccines immunise a person against disease?
The body is injected with a small amount of dead or inactive pathogens. These pathogens carry antigens and, despite being harmless, cause the body’s white blood cells to produce antibodies to eliminate them. The production of antibodies creates immunity against that pathogen in the future as white blood cells are able to recognise them quickly.
