IMMUNE 2 Flashcards
what does vasodilation of local arterioles result in
hyperemia (increased blood flow), which brings more immune cells and chemicals to the injured area ad causes redness and heat
what does vasodilation increase
capillary and venule permeability
what does increased capillary and venule permeability cause to seep from blood to tissue
Exudate (fluid w/clotting factors and antibodies)
what does increased capillary and venule permeability sweep
foreign substances into lymphatic system
what do increased capillary and venule permeability deliver
clotting factors → form fibrin mesh scaffold for repair and isolation of area
what does increased capillary and venule permeability cause
swelling and pain
what are the four steps to mobilize phagocytes
leukocytosis, margination, diapedesis, chemotaxis
how does leukocytosis happen
increase in white blood cells; neutrophils enter blood in response chemical release
what do phagocytes do in margination
cling to inner walls of capillaries
what do infumaed endothelial cells sprout during maringation + what adheres to them
cell adhesion molecules (CAMs) - Neutrophils adhere to CAMs
what do neutrophils do during diapedesis
flatten and squeeze through capillary walls
what do inflammatory chemicals draw during chemotaxis
draw neutrophils and WBCs to site of injury; devour foreign material
what do antimicrobial proteins do to microorgansms
attack directly or prevent reproduction
what are larger antimicrobial proteins usually
usually lytic enzymes
what do lytic enzymes do to pathogens
break them apart
what do smaller antimicrobial proteins do
act by disrupting structure/function of microbial cell membranes / plasma membrane
what are the three types of antimicrobial proteins
1) Interferons
2) Complement
3) Transferriniron-binding
what are examples of proteins (1) and macromolecules (2) of larger antimicrobial proteins
nutrient binding proteins, or target specific microbial macromolecule
what are interferons
small proteins secreted by virus-infected cells to protect/warn non-infected cells
what do interferons stimulate production of
proteins that “interfere” with viral replication in healthy cells
what do interferons have an indirect role in
fighting cancer
what are some tasks of alpha + beta and gamma interferons
α and β (alpha and beta) interferons:
» Anti-viral properties
» Activate natural killer cells
γ (gamma) interferons:
Secreted by lymphocytes
» Activate macrophages
» Enhances T cell activity
what happens after interferon warns healthy cell
healthy cell turns on genes for antiviral proteins which block viral reproduction
what are complement antimicrobial proteins
system of ~20 plasma proteins that normally circulate in inactive state that come together to complement the effectiveness of the innate and adaptive defenses
what are complement antimicrobial proteins activates by
pathogens or pathogen-bound antibodies
what are the three pathways of antimicrobial proteins
1) Classical
2) Lectin
3) Alternative
describe the classical pathway
activated by antibodies in target cell
describe the lectin pathway
activated by lectins biding to specific sugars on microorganisms surface
whats the alternative pathway
activated spontaneously; lack of inhibitors on microroganism’s surface allows process to proceed
do all pathways come together
yes, at C3 to initiate final complement
what are the two options after pathways come together at C3
enhances inflammation; opsonization
describe how the three complement pathways enhance inflammation
stimulates histamine release, increased blood vessel permeability, attracts phagocytes by chemotaxis
whats opsonooizationn
coats pathogen surfaces, which enhances phagocytosis
what are two ways to describe fever
- Abnormally high body temperature
- Systemic response to invading microorganisms
how does fever act on hypothalamus to increase body temp
leukocytes and macrophages are released to act on the foreign substance, which release pyrogens to increase body temp
why is a high fever dangerous
denatures enzymes
why does liver hoard zinc and iron during fever
needed to bacteria growth, so hoarding them can prevent bacteria growth
why does fever increase metabolic rate of tissue cells
speeds up repair
what must the third line of defense be activated by
initial exposure, unlike innate (vaccines!)
what does it mean that the adaptive defense is antigen specific
recognizes and is directed toward specific antigens
what does it mean that the adaptive immune system is systemic
immunity not restricted to initial infection site
what does it mean that the adaptive immune system has memory
after initial exposure, it recognizes and mounts even stronger attacks on the previously encountered pathogen
what are the two types of immunity in adaptive defense
humoral and cellular
what humoral immunity adapted by
Antibody-mediated immunity
- Freely circulating antibodies (from B cells) mark pathogens for destruction
what cellular immunity adapted by
cells
what do lymphocytes (T cells) do in cellular immunity
attack virus, parasite infected cells, and cancer cells; direct and indirect
differentiate between direct and indirect lymphocytes
» Direct: kill pathogens themselves
» Indirect: amplify inflammatory response allowing phagocytes to take out the pathogen
what are antigens
Substances that can trigger adaptive defenses
what are complete antigens
can mobilize immune system and provoke an immune response
» eg. pollen, bacteria, fungi, virus particles
whats immunogenicity
ability to stimulate proliferation of specific lymphocytes and antibodies
whats reactivity
ability to react with the released antibodies and activated lymphocytes
what are incomplete antigens (haptens)
reactive but not immunogenic
- A chemical that only serves as an antigen when it is bound to a protein in the body
» eg. found in animal dander, detergents, cosmetics, poison ivy
