Immunity Flashcards
What is a virus?
An infectious microbe consisting of a segment of nucleic acid (either DNA or RNA) surrounded by a protein coat. They cannot replicate independently but instead rely on a host cell. They typically insert their genetic material into the host cell and then the use the host cell machinery to replicate the virus.
What are Protozoa?
Single celled organisms
E.g. Plasmodium which causes malaria
What are Parasitic worms/Helminths?
Large microparasites that are soil transmitted and infect the GI tract. They feed on a living host to gain nourishment and protection while causing poor nutrient absorption, weakness and disease in the host.
What is different between a gram positive bacteria and a gram negative bacteria?
Gram positive- lack an outer membrane but are surrounded by layers of peptidoglycan many times thicker than is found in gram negatives
Gram negative- thin peptidoglycan cell wall which is then surrounded by an outer membrane containing lipopolysaccharide
What colours do gram positive and gram negative bacteria stain?
Positive= stains purple
Negative = red/pink
What are 3 main shapes of bacteria?
Cocci- circular
Bacilli- Rod
Spirochaetes- Helical
What do antibiotics do?
Kill or slow the growth of bacteria
Do viruses contain RNA or DNA?
They can contain either but NOT BOTH!
What can antiviral medicines do?
They can block receptors so viruses can’t bind to and enter healthy cells
Boost the immune system, helping it fight off a viral infection
Lower the viral load (amount of active virus) in the body
What causes prion diseases?
This is when proteins in the brain misfold causing symptoms.
What is meant by the following terms?
Mutualism
Commensalism
Parasitism
Mutualism (symbiosis)- Both microbe and host benefit from the association
Commensalism- Microbe benefits from the association, no harm to host
Parasitism- Host is damaged while microbe benefits.
Can UTIs spread?
No they cannot spread from person to person like an STI. They occur when bacteria on usually your own skin or rectum comes into contact with your urethra and infects your urinary tract.
When taking blood from your finger for a blood smear, should you squeeze your finger to draw blood?
No- as this dilutes the blood
What are neutrophils?
How many lobes to the Nucleus do they have?
They are part of the innate immune response. They are very toxic to bacteria and fungi. They are typically the first cell to arrive at a site of infection. They are a type of phagocyte.
They have a multilobed nucleus (usually 2-6)
What are Eosinophils?
What does the nucleus look like?
They are part of the innate immune response. They secrete a range of highly toxic proteins and free radicals that kill bacteria and parasites.
They have 2 lobes to the nucleus
What are Basophils?
Part of the innate immune response. Basophils release histamine which plays a key role in mounting an allergic response.
They have lots of granules in their cell which masks the nucleus
What is a zoonotic infection?
An infection that spreads from animals to humans
What is the major difference between bacteria and for example protozoa and fungi?
Bacteria are prokaryotes while the rest are eukaryotes
What is the transmission of mother to child called?
Vertical transmission
Which cells of the innate immune system do you usually find in the blood?
Monocytes, Natural Killer cells, Neutrophils
What is a pyrogen?
A fever inducing substance
What are physical barriers of the body?
Mucociliary escalator, Skin (including sebum- oily secretion), Lacrimal apparatus (tears), Saliva, Gastric Juice, Urine, Body temperature