Non Specific Immune Defenses Flashcards
Non specific immune defenses
does not stimulate the immune system to produce antibodies
affects all microorganisms the same way
1st line of defense (3)
- structural
- mechanical
- biochemical
structural defense
skin
mucous membreanes
mechanical defense
mucociliary defense
force of urine
tears
sneezing, coughing, talking and sneezing
biochemical defense
keratin
lysozymes
bile
acids
2nd line of defense (6 characteristics)
- inflammation
- phagocytosis
- fever
- interferon
- natural killer cells
- complement system
function of inflammation
destroys or removes microbial agents
isolates microbial agents if they can’t be removed
clean up and regenerate host tissue
2 stages of inflammation
- release of inflammatory mediators- indicate site of infection
- vasodilation of capillaries- increase membrane permeability, dilutes toxins, delivers O2, nutrients and clotting proteins
inflammatory mediators
bacterial byproducts complement fragments histamine kinins mast cells
phagocytes
macrophages and neutrophils
opsonization
phagocyte coats pathogen with compliment proteins or antibodies to enhance phagocytosis
phagocyte activation steps (4)
- leukocytosis
- margination
- emigration
- phagocytosis
leukocytosis
neutrophils form in red bone marrow
margination
neutrophils accumulate in capillaries of injured area
emigration
diapedesis
neutrophils enter tissues
phagocytosis
neutrophils engulf pathogens and debris
destroy pathogen with enzymes
fever
hypothalamus responds to pyrogen chemicals in blood
hypothalamus releases prostaglandins to reset body T higher
interferon
signal proteins produced by virus infected cells
stimulate healthy cells to produce antiviral proteins
natural killer cells
special T lymphocytes
respond before C cytotoxic cells
attack cancer cells, viruses and other cells without MHC self-antigens
release perforins to lyse membranes
complement system
large serum proteins
act as inflammatory mediators
form opsonins
form MAC complexes
complement systems activation
when large proteins are fragmented into smaller pieces
2 complement pathways
classical
alternate
classical complement pathway
part of SPECIFIC immune response
recognizes antigen/antibody complex
alternate complement pathway
NON SPECIFIC
binds cell wall components on bacterium
does not require antigen/antibody complex
interferon types
Alpha, Beta- target virus infected cells
Gamma- antigen binding cells, T cells
