11.2 immunity Flashcards
what is part of innate defenses? what is art of adaptive defenses?
Innate: surface barriers and internal defenses
Adaptive: Humoral (B cells) and Cellular (T cells) immunity
describe the skin as a line of defense
- mechanical barrier that prevents entry of harmful substnaces
- acid mantle: skin secretions are acidic (inhibits bacterial growth) & contains bactericidal chemicals
- keratin provides resistance against acids, alkalis and bacterial enzymes
describe the role of intact mucous membranes in surface barriers, what are there
- mechanical barrier that prevents entry of pathogens
- nasal hairs filter and trap microorganisms
- mucos traps them in respiratory and digestive tracts, cilia propel mucus twds epiglottis
- gastric juice high in HCl and protein digesting enzymes
- acid mantale of vagina inhibits most bacterial and fungal growth
- lacrimal and salivary glands lubricate eyes/mouth + contain lysozyme
- urine is acidic (inhibit bacterial growth)
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role of cells as internal defenses
- phagocytes engulf and destroy pathogens that break surface membranes
NK cells: promote apoptosis by attaching virus infected or cancer body cells
*2nd line of defense
describe interferons
Antimicrobial proteins
*2nd line
*help protect other cells from also being infected, does not save initial cell
- proteins released by virus infected cells & certain lymphocytes
- act as chemical messengers to protect uninfected tissue cells from viral takeover
- mobilize immune system
describe complement
* antimicrobial proteins - second line of defense
- group of blood borne protiens that lyse microorganism when activated
- enhance phagocytosis by opsonisation and intensif inflammatory and other immune responses
*form membrane attack complexes and encourage macrophages to come
inflamation as an internal defense
*2nd line
- results in heat, redness, pain and swelling
- bringing more blood to area to flush eveyrthing out
fever as an internal defense
- high body temperature inhibits micrboes from multiplying and enhances body repair process
role of B cell in immune response
- matures in bone marrow
- forms plasma memory cells
role of plasma cell in adaptive immune repsonse
antibody producing machins
- is an effector B cell
role of T cells in adaptive immune repsonse
- Helper T cells have CD4 protien
- involved in humoral and cellular immunity
- stimulates production of cytotoxic T cells and plasma cells
- activates macrophages, acts directly and indirectly be releasing cyokines
- Cytotoxic cells have CD8 protein
- kills invaded body cells and cancer cells
role of memory cell in adaptive immune repsonse
- descendant of activated B cell or any class of activated T cell
- generated during initial immune response
- amy exist in body for years so it can respond quickly and efficiently to subsequent encounters with same antigen
role of antigen presenting cells in adaptive immune repsonse
- can be dendritic, macrophage or B cell that engulfed and bidgested an antigen
- presents part of antigen on PM bound to a MHC to be recognized by T cells
- function, antigen presentation is essential for activation of T cells
what is involved in humoral immunity
- get an antigen-antibody complex
- compliment bindss, fixes and activates to lead to lysis
- inacivated by: neutralization, aggulination and precipitation
hummoral immunity does PLAN
Pricipittation, Lysis, Agglutination, Neutralization
describe the primary response of humoral immunity
*initial encounter with Ag
- Ag bidns to receptor on specific B lymphocyte (B lymphocytes with noncomplementary receptors remain inactive)
- this activates B cell which then go to plasma cells, which secrete antibodies and initiate “PLAN”
- plasma cells also form memory B cells (primed to respond to same Ag)
secondary response of humoral immunity
- same antigen inquired so get more rapid reponse die o memory B cells
what are the types of humoral immunity
- Active
- Naturally acquired: infection, contact with pathogen
- Artificially acquired: vaccine
- Passive (no memory)
- Naturally acquired: antibodies passed from mother to feetus via placenta or infant in milk
- Artifically acuqire; injection of exogenous antibodies (gamma globulid)
what are the different types of antibodies
*humoral immunity: 3rd line of defense
- B cells switch from making one class of Ab to antoher as they become plasma cells
- IgM (pentamer):
- First Ab released in primary response
- Readily fixes & activates complement
- Potent agglutinating agent
- IgA (dimer)
- Found in body secretions (saliva, sweat, intestinal juice & milk)
- helps stop pathogens from attaching to epithelial cell surfaces
- IgD (monormer)
- Found on B cell surfaces
- IgG (monomer)
- Most abundant Ab in plasma (75-85% of circulating Ab)
- main Ab for secondary and late primary responses
- crosses placenta to give passive immunity
- IgE (monomer)
- stem end bidns to mast cells or basophila
- mediates inflammation and allergic rxn
what is main Ab in primary respons? in secondary response?
IgM: primary repsonse
IgG: seoncdary and late primary
describe class I MHC
- desplayed on: all nucleated cells
- Regognized by: Native CD8 cels and cytotoxic T cells
- Foreign antigens on MHC are: endogenous (intracellualr pathogens or proteins made by canerous cells)
- > if cell is an APD: i belong to celf but have captured foreign invader, this is what it looks like, kill any cell that displaces it
- > if cell is not an APD: i belond to cell but have been anvaded or beomce cancous, kill me
decribe class II MHC
- desplayed on: APC (dendritic cells, macrophages, B cells)
*found bacterial and ate it, here is what it looks like)
- Regognized by: Naive CD4 cells and T helper cels
- Foreign antigens on MHC are: exogenous (phagocytied extracellular pathogens)
* i belong to self, but have captured foreign invader, this is what it looks lik,e help me mount a defense against it
