Musocal Immunity

Question 1

Inductive site

Answer 1

regional MALT and epithelial cells containing M-cells

Question 2

Gut-associated Immune System

Answer 2

Continuously exposed to foreign non-pathogenic and pathogenic antigens

Gut is the largest lymphoid organ

Question 3

Protective functions of gut flora

Answer 3

Pathogen displacement
Nutrient competition
Production of anti-microbial factors

Question 4

Structural functions of gut floa

Answer 4

Barrier fortification
Induction of IgA
Tightening of tight junctions
Immune system development

Question 5

Metabolic functions of gut flora

Answer 5

Synthesis of vitamins
Fermentation  of non-digestible dietary residues and mucous
Ion absorption
Salvage of energy
Formation of by-products

Question 6

Functions of mucosal immunity

Answer 6

1. Maintains immunological homeostasis along epithelial surface
2. Mediates symbiotic relationship between host and endogenous organism
3. First line of defense

Question 7

Anatomical organization of GALT

Answer 7

Peyer's patches (small intestine)
Lymphoid follices (entire gut)

Question 8

Immune cells of lamina propria

Answer 8

IgA
Memory T and B cells
Effector T cells
Dendritic cells, macrophages, mast cells

Question 9

Immune cells of the epithelium

Answer 9

Intraepithelial lymphocytes (effector T-cells)

Question 10

Functions of IgA

Answer 10

1. Binds and neutralizes pathogens
2. Neutralizes intracellular LPS
3. Exports pathogens and toxins to apical surface
4. Limits access of pathogens to mucosal surfaces without risking inflammatory damage