Immunity Flashcards
What is the difference between a gram + and a gram - bacteria?
Gram - has an extra cell wall which prevents the dye (ethyl violet) from changing the color of the peptidaglycan layer
What is the difference between a cocci and a bacillus bacteria?
cocci- sphere shaped
bacillus- rod shaped
What type of climate would be ideal for an aerobic bacteria?
- Requires O2, would die without it
- found on skin and in respiratory tract
What type of climate does a microaerobic bacteria need?
- Needs a little O2, but cannot tolerate lots
- found in stomach
What type of climate does a Facultative anaerobic bacteria need?
- Can use O2 if they have it, but can survive without it
- not great at either
What type of toxin do gram - and gram + bacteria release?
- Gram - : endotoxin
- release by bacterial cell death
- Gram + : Exotoxin
- secreted from live bacteria (ex. botulinum toxin)
What is a spore?
- Hard shell around a bacteria makes it extremely difficult to kill.
- It will emerge from spore when environment is improved.
Staphylococcus
gram stain
O2 req
shape
characteristic
Gram +
Aerobic
cocci
clusters
1st and 2nd most common bact. b/c of MRSA
Streptococcus
gram stain
O2 req
shape
characteristics
gram +
aerobic
cocci
chains, pairs
Clostridium
gram stain
O2 req
shape
characteristic
Gram +
anaerobic
bacilli
spore forming
What are the 4 clostridiums that cause disease in humans?
perfingens
difficil
botulinum
tetanus
Bacillus
gram stain
O2 req
shape
characteristics
Gram +
aerobic
bacilli
spore forming
Bacteroides
gram stain
O2 req
shape
characteristic
Gram -
anaerobic
bacilli
Most common cell in body
What is a plasmid?
DNA found in bacteria that is separate from it’s chromosomal DNA. Contains genes that give the bacteria a genetic advantage (superpower).
Can be easily shared to other bacteria via a Pilus
How does a virus infect a host cell?
- becomes attached to a specific plasma protein
- releases enzymes that weaken the membrane and allow it to enter the cell
- uncoats itself
- enters the nucleus and the host cell replicates it
- matures and escapes cell to infect other host cells
What are the three most medically relevant Fungi and what do that do?
- Candida albacans
- normal gut flora
- causes opportunistic infections
- Aspergillus spp.
- highly aerobic
- causes respiratory infections
- Tinea (skin plant):
- Capitus- head
- cruris-jock
- pedis- foot
What happens after a Mast cell has been activated?
- Degranulation- release of the active substances the cell holds
- histamine- causes vascular effects
- chemotactic factors- attracts neutrophils and eosinophils
- Synthesis- lipid based molecules are made out of the phospholipids of the plasma membrane
- platelet activator
- prostaglandins
- leukotrienes
What are the stages of inflammation?
- Initiate response- vessel leakage
- Recruitment of cells- chemotaxis, leukocyte growth and proliferation
- Remove debris- activate leukocytes, lymphocyte growth, and antibody synthesis
- Promote repair and regeneration- induce fibroblast growth and collagen production
epitope
the part of the antigen (a large polysaccharide or protein) that is recognized by the antibody.
IgA
IgE
IgG
IgM
- IgA- Gets secreted into orifices
- GI, bronchi, mouth, vagina
- IgE- tissue
- IgG- blood
- IgM- all of them start as IgM
Describe the structure of an Antibody
An antibody is made up of a light chain and a heavy chain. The light chain is made specifically to bind with an antigen. The heavy chain is constant and easy for the macrophages to recognize.
How is a parasite destroyed (with IgE)?
- Antigens released by the parasite cause B-cells to produce IgE antibody
- IgE binds to the mast cell surface
- Antigens from the parasite then link to the IgE on the mast cell
- causes the mast cell to degranulate, causing inflammation and releasing chemotactic factor
- Eosinophils are attracted by the chemotactic factor and come
- Eosinophil attaches to the parasite and releases lysosomal enzymes that damage it
What is the difference between primary and secondary immune response?
- Primary immune response
- IgM dominates
- process takes longer
- IgG response is much smaller
- Secondary immune response
- Response happens much quicker
- larger amounts of IgG are produced
What is a Peyer’s patch and how does it function?
- Peyer’s patch- an aggregation of lymphoid tissue found in the ileum.
- antigens in the lumen of the digestive tract are captured by M-cells
- antigen is recognized by B-cells and they are displayed by APCs to Thelper cells
- B-cells are stimulated by TH cells to become IgA-secreting plasma cells which are then transported into the intestinal lumen.
What is the difference between Class I and Class II MHC cells?
- Class I
- found on all nucleated cells and platelets
- presents “endogenous” antigens
- Class II
- found on B cells, APCs, and some epithelial cells
- presents “exogenous” antigens
What areas are immune privileged?
placenta/fetus
testes and ovaries
eyes
brain thymus
What type of climate is ideal for an obligate anaerobe?
- Cannot tolerate oxygen
- Found in colon or deep penetrating wounds
