Immunology Flashcards
which part of the GI tract plays the largest role in immunity?
Colonic mucosa
how does colonic mucosa identify pathogens
detects and recognises luminal contents, then differentiates between antigens of ‘good bacteria’ and pathogens.
what happens if the immune system is responsive to self- antigens
autoimmune disease
what must immune system not be responsive to
- own antibodies
- food
- good bacteria/ normal flora
function of epithelial layer of gut in terms of immunity
tight junctions enable epithelial layer to act as a barrier, which decides what goes from lumen side into the host
function of mucous layer in lumen
physical barrier keeping microbes from host cells
examples of antigen presenting cells:
- dendritic cells
- macrophages
innate immune response
initial immune response at site of insult
adaptive immune response
more specialised, developed over time (e.g. from previous infection)
cells involved in innate immune response
granulocyte mast cell monocyte dendritic cell macrophage natural killer cell
cells involved in adaptive immune response
T cells
b cells
plasma cells
function of cytokine proteins in immune response
decide what happens to cells, and how T cells should differentiate
they are produced by cells and act on cells
Describe Peyers Patches
specialised lymphocyte aggregations - sample whats in the lumen by reaching across epithelium to take a bit of the protein. they well then pass these on to antigen presenting cells, who pass them to T cells to make a response decision
describe macrophages
- phagocytic
- first line of defence in the gut
- sample particular antigens
function of dendritic cells in mucosal immunity
- can give rise to different T cell responses (tolerance vs. immunity)
- distinguish cell markers
- DC presents antigens to indecisive T cells