Immunity

Question 1

2 types of adaptive immunity

Answer 1

Humoral immunity

Cell mediated immunity

Question 2

Humoral immunity

Answer 2

Against extracellular microbes and their toxins
Antibody mediated
1. Antigen presenting cell that expresses MHC II- macrophage, dendritic or b cell engulf the pathogen
2. Pathogens antigens are presented on cells surface
3. CD4+ T helper cell recognises these antigens
4. This activates the t helper cell
5. Helper T cell releases cytokines
6. Cytokines stimulate the production of B cells
7. B cells divide into either memory b cells or plasma cells
8. The plasma cells secrete antibodies IgM, IgA, IgD, IgE, or IgG
9. These cells are then released into the blood where its antibodies attach to complementary antigens by neutralisation complement activation forming antigen-antibody complex
10. Extracellular microbes are then cleared and eliminated and infection is blocked
11. Memory b cells remain in body and provide a heightened immune response if the same microbe is encountered by the body again

Question 3

Cell mediated T helper cell immunity

Answer 3

1. Antigen presenting cell that expresses MHC II- macrophage, dendritic or b cell engulf the pathogen
2. Pathogens antigens are presented on cells surface
3. CD4+ T helper cell recognises these antigens
4. T helper cells binds to these antigens on surface of MHC II cells
5. Helper T cell becomes activated releases cytokines
6. Cytokines cause differentiation of t cells, b lymphocytes, macrophages and natural killer cells
7. T cells differential into memory t cells or cytotoxic t cells

Question 4

Cell mediated cytotoxic T cell immunity

Answer 4

1. Antigen presenting cell that expresses MHC II- macrophage, dendritic or b cell engulf the pathogen
2. Pathogens antigens are presented on cells surface
3. CD4+ T helper cell recognises these antigens
4. T helper cells binds to these antigens on surface of MHC II cells
5. Helper T cell becomes activated releases cytokines
6. Cytokines cause differentiation of t cells into cytotoxic t cells
7. These cytotoxic t cells can differentiate into memory cytotoxic t cells
8. They can also fuse with the cell membrane of the target cell and release their toxins into target cell
9. Cytotoxins include perforin which forms pores in target cell membrane and the infected target cell is killed by apoptosis

Question 5

Innate immunity

Answer 5

No memory cells
produces the same response
rapid first line of defence
non-specific 
naturally occuring immunity
no allergic reaction produced

Question 6

Innate immunity barriers

Answer 6

Anatomic= skin, mucous
Chemical= lysosomes in tears, stomach acidity 
Physiological= temperature, ph

Question 7

Innate immunity phagocytosis

Answer 7

• Ingestion of microbe by phagocyte
• Folds around microbe to form phagosome
• Metabolic reactions occur in phagosome membrane- generates toxic O2 and N2 radicals which further help to damage the microbe
• Fusion of phagosome with lysosome= phagolysosome
• These microbe damaging enzymes and cationic protein combination lower ph and allows phagocytes to kill microorganism

Question 8

Innate immunity inflammatory defence barriers

Answer 8

• Vasodilation
• Increase in capillary permeability
• Phagocyte influx

Question 9

Innate immune response cells involved

Answer 9

dendritic
NK
plasma proteins
monocyte
macrophage
eosinophils
neutrophils

Question 10

Adaptive immune response

Answer 10

Not naturally present occurs in response to antigens
slow= days and weeks
memory cells
very specific

Question 11

Adaptive immune response cells involved

Answer 11

B cells

t cells- helper and cytotoxic