Immune System Flashcards
What are the different types of pathogens?
Viruses Bacteria Parasites Fungus & yeasts Prions
What does the immune system do?
Defence against disease-producing agents (pathogens)
What are the properties of a virus?
Infectious particles, rather than living cells.
Cannot replicate on their own but must hijack the hosts genetic machinery.
What can a virus not do?
Replicate on its own.
What are the properties of a bacteria?
Multiply quickly
True living cells,
larger and more highly organised than viruses.
Can multiply outside the host cell. (Binary fission)
They grow rapidly, dividing roughly once every 20 minutes in ideal conditions.
What is the process of the bacteria multiplying outside the cell called?
Binary fission
In ideal conditions how rapidly does bacteria grow?
Divide roughly once every 20 minutes
Parasites can be be put into 2 categories. What are they?
Single-celled (protozoa)
Multicellular (helminths)
Where are single-celled (protozoa) parasites found?
Live freely in soil or water.
Can u name any parasitic single celled diseases?
Malaria
Amoebic dysentery
Giardia (affects small intestine)
Where are multicellular (helminths) parasites found?
Inhabit the guts of animals
How are multicellular parasites transmitted?
Faeces or ingestion
Can you name any multicellular (helminth) parasites?
Roundworm
Tapeworm
Threadworm
Liver fluke
What are the properties of yeast & fungi?
Cause diseases known collectively as mycoses.
Why are mycoses important in people with compromised immune systems?
Cause “opportunistic infections”
Give an example of an opportunistic infection?
Oral thrush (candida)
What are prions?
Abnormal proteins
What conditions can prions cause?
CJD (creutzfeld-Jacob disease)
CJDv (new variant CJD)
Kuru
What is the immune systems second line of defence?
Blood & lymph
When would the immune systems second line of defence be recruited?
If pathogens breach the physical & chemical defences.
What is involved in the second line of defence in its simplest form?
Huge array of blood cells & circulating proteins
What 2 components is the human immune system divided into?
Natural (innate) immune system
Adaptive immune system