Topic 12 Flashcards
2 types of resistance
- innate
- adaptive
Innate
prevents entry of microbes into body or remove foregone material.
Physical barriers for innate
skin, mucous membranes
Mechanical barriers for innate
flow of tears, sweat, mucus, cilia beating, coughing, sneezing
Chemical barriers for innate
- gastric acid, lysozyme (salvia, tears)
- interferons = produced by virus infected cells. trigger mechanisms in nearby uninfected cells that prevent infection
Normal micro biome for innate
outcompete newcomers
Phagocytes for innate
macrophages and neutrophils
Inflammation for innate
local tissue damage. release of chemicals (ex: histamine (vasodilator) from mast cells. results in swelling, heat, redness, pain/loss of function.. attracts neutrophils and then macrophages
Fever for innate
immune cells and microbe chemicals trigger release of prostaglandins in hypothalamus, increase in temp.
Aspirin/ibuprofen/acetaminophen
decreases prostaglandin synthesis so decrease in fever
Natural killer cells
used in inmate resistance
Adaptive immunity
production of specific lymphocyte or antibody against recognized antigen.
Antigen (Ag)
protein/polysaccharide recognized as foreign by immune system (parts of bacteria, virus, pollen, parasites, transplants)
Antibody (Ab)
plasma protein (y globulin) matches a specific Ag. produced by plasma cells
1st step in immune response
phagocyte (macrophage) eats invader and displays parts of it (Ag) on its surface
2nd step in immune response
Th binds and is activated (proliferates). releases chemical which maya activate cytotoxic T lymphocytes or B cells
If cytotoxic T lymphocytes are activated..
they proliferate and directly destroy cells contain virus, cells altered by cancer or translated organs
When cytotoxin T lymphocytes are activated its called..
cell mediated immunity
If B cells are activated
proliferate and convert to plasma cells then antibody.
When B cells are activated its called…
humoral (antibody mediated) immunity
Memory B/T cells also produced ..
long lived permit rapid response on next encounter with some Ag
2 types of humoral immunity
- active
- passive
Active immunity
lasts years. body makes Ab, memory B cells after exposure to disease organ (natural) OR injection with killed/inactivated disease organ/ vaccination (artificial)
Passive immunity
lasts weeks (give Abs and lasts as long as Abs is present)
Natural passive immunity
mother to baby across placenta/ in milk
Artificial passive immunity
produced Ab (from person, animal, monoclonal) and injected for tetanus, rabies, snake bites, Rh favour. it mops up Ag before it can trigger an immune response in person
