11.2 immunity

Question 1

what is part of innate defenses? what is art of adaptive defenses?

Answer 1

Innate: surface barriers and internal defenses

Adaptive: Humoral (B cells) and Cellular (T cells) immunity

Question 2

describe the skin as a line of defense

Answer 2

• 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

Question 3

describe the role of intact mucous membranes in surface barriers, what are there

Answer 3

• 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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Question 4

role of cells as internal defenses

Answer 4

• 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

Question 5

describe interferons

Answer 5

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

Question 6

describe complement

Answer 6

* 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

Question 7

inflamation as an internal defense

Answer 7

*2nd line

• results in heat, redness, pain and swelling
• bringing more blood to area to flush eveyrthing out

Question 8

fever as an internal defense

Answer 8

• high body temperature inhibits micrboes from multiplying and enhances body repair process

Question 9

role of B cell in immune response

Answer 9

• matures in bone marrow
• forms plasma memory cells

Question 10

role of plasma cell in adaptive immune repsonse

Answer 10

antibody producing machins

• is an effector B cell

Question 11

role of T cells in adaptive immune repsonse

Answer 11

• 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

Question 12

role of memory cell in adaptive immune repsonse

Answer 12

• 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

Question 13

role of antigen presenting cells in adaptive immune repsonse

Answer 13

• 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

Question 14

what is involved in humoral immunity

Answer 14

• 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

Question 15

describe the primary response of humoral immunity

Answer 15

*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)

Question 16

secondary response of humoral immunity

Answer 16

• same antigen inquired so get more rapid reponse die o memory B cells

Question 17

what are the types of humoral immunity

Answer 17

• 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)

Question 18

what are the different types of antibodies

Answer 18

*humoral immunity: 3rd line of defense

• B cells switch from making one class of Ab to antoher as they become plasma cells

1. IgM (pentamer):
   
   • First Ab released in primary response
   • Readily fixes & activates complement
   • Potent agglutinating agent
2. IgA (dimer)
   
   • Found in body secretions (saliva, sweat, intestinal juice & milk)
   • helps stop pathogens from attaching to epithelial cell surfaces
3. IgD (monormer)
   
   • Found on B cell surfaces
4. 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
5. IgE (monomer)
   
   • stem end bidns to mast cells or basophila
   • mediates inflammation and allergic rxn

Question 19

what is main Ab in primary respons? in secondary response?

Answer 19

IgM: primary repsonse

IgG: seoncdary and late primary

Question 20

describe class I MHC

Answer 20

• 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

Question 21

decribe class II MHC

Answer 21

• 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

Question 22