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
Q

State three infections of the GIT.

A

Oral candidiasis
Helicobacter pylori
Traveller’s Diarrhoea

2
Q

What does H. pylori cause?

A

Increased acid secretion

3
Q

State three causes of Traveller’s Diarrhoea.

A

Escherichia coli
Salmonella
Shigella

4
Q

Name a superbug.

A

Clostridium difficile

5
Q

What is the treatment for C. difficile?

A

Metronidazole and Vancomycin

6
Q

What components make up mucosal defence?

A

Anatomical and chemical barriers
Commensal bacteria
GALT and MALT

7
Q

What makes up the epithelial barrier?

A

Goblet cells, Paneth cells, antimicrobial peptides, secretory IgA

8
Q

What is GALT and what does it do?

A

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

9
Q

What do Peyer’s Patches consist of?

A

Naïve T and B cells

10
Q

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

A

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

11
Q

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

A

Lamina Propria

12
Q

Where do activated T and B cells go to proliferate?

A

Superior Mesenteric Lymph Nodes

13
Q

What is the role of secretory IgA?

A

Prevent attachment and entry of pathogens

14
Q

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

A

Intraepithelial lymphocytes

15
Q

What is the difference between conventional and unconventional T cells?

A

Conventional - migrate from other tissues

Unconventional - resident

16
Q

What other innate cells are involved?

A

NK cells

17
Q

What three signals determine the T cell response?

A

Presentation of antigen on MHC
Costimulation
Cytokines

18
Q

What are the mechanisms of immune tolerance?

A

Anergy
Deletion
Regulation (Tregs)

19
Q

What is Crohn’s disease?

A

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

20
Q

Name 4 structures where GALT is ORGANISED

A

Cryptopatches
Peyer’s Patches
Isolated lymphoid follicles
Mesenteric lymphoid follicles

21
Q

Name 2 places where GALT isn’t organised

A

Intra-epithelial lymphocytes

Lamina propria lymphocytes