GI Flashcards
Where are Peyer’s patches found?
Ileum
Where can antigen capture occur in the GI tract?
both in Peyer’s patches and
directly across the epithelium
Which cells can extend process across the epithelium and capture antigens?
Dendritic cells
What are Peyer’s patches covered by?
Epithelial layer containing specialised cells called M cells with characteristic membrane ruffles
How do M cells take up antigens?
endocytosis and phagocytosis
How is the antigen transported across M cells and where is it released?
In vesicles, and at basal surface
What is the antigen bound by and what do these activate?
Dendritic cells, these activate T cells
Where is intestinal immune response initiated
mesenteric lymph nodes
Does the lymphoid tissue in the gut contain M cells and B cells?
yes
How do T cells enter Peyer’s patches?
from blood vessels directed by receptors CCR7 and L-selectin
What are T cells in Peyer’s patch activated by?
dendritic cells
What happens when T cells are activated in GALT?
CCR7 is lost and cells can no longer recirculate
What does the polarised columnar monolayer separating the microbiota
from the lamina propria consist of?
- enteroabsorptive cells, 2. goblet cells, 3. neuroendocrine cells, 4. paneth cells and 5. M cells
Does the large intestine contain crypts?
Yes
Does the large intestine contain villi?
No
