Immunological Mechanisms and Infections of the GIT Flashcards Preview

LSS 2 - Alim - Laz > Immunological Mechanisms and Infections of the GIT > Flashcards

Flashcards in Immunological Mechanisms and Infections of the GIT Deck (21)
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1

State three infections of the GIT.


Oral candidiasis
Helicobacter pylori
Traveller's Diarrhoea

2

What does H. pylori cause?


Increased acid secretion

3

State three causes of Traveller's Diarrhoea.


Escherichia coli
Salmonella
Shigella

4

Name a superbug.

Clostridium difficile

5

What is the treatment for C. difficile?


Metronidazole and Vancomycin

6

What components make up mucosal defence?


Anatomical and chemical barriers
Commensal bacteria
GALT and MALT

7

What makes up the epithelial barrier?

Goblet cells, Paneth cells, antimicrobial peptides, secretory IgA

8


What is GALT and what does it do?


Collections of T and B cells which generate lymphoid cells and antibodies
Produces secretory and interstitial IgA, IgM, IgG and cell mediated immunity

9

What do Peyer's Patches consist of?

Naïve T and B cells

10

How is the epithelium above Peyer's patches different to normal gut epithelia?

It is Follicle Associated Epithelium (FAE) - there are no goblet cells, no microvilli and no secretory IgA

11


In which layer of the gut wall are Peyer's patches found?

Lamina Propria

12


Where do activated T and B cells go to proliferate?

Superior Mesenteric Lymph Nodes

13


What is the role of secretory IgA?

Prevent attachment and entry of pathogens

14

What immune cell makes up 1/5 of intestinal epithelium?


Intraepithelial lymphocytes

15

What is the difference between conventional and unconventional T cells?


Conventional - migrate from other tissues
Unconventional - resident

16

What other innate cells are involved?

NK cells

17


What three signals determine the T cell response?

Presentation of antigen on MHC
Costimulation
Cytokines

18


What are the mechanisms of immune tolerance?


Anergy
Deletion
Regulation (Tregs)

19

What is Crohn's disease?






Inflammatory thickening of the bowel wall - leads to ulceration, diarrhoea and pain

20

Name 4 structures where GALT is ORGANISED

Cryptopatches
Peyer's Patches
Isolated lymphoid follicles
Mesenteric lymphoid follicles

21

Name 2 places where GALT isn’t organised

Intra-epithelial lymphocytes
Lamina propria lymphocytes