Wk 3 - Immunology: GI Mucosa and Coeliac Disease

Question 1

What is the definition of mucosa?

Answer 1

‘mucosa’ a membrane rich in mucous glands which lines body cavities and passages (as of the gastrointestinal or respiratory tract) which communicate directly or indirectly with the outside of the body

Question 2

What is the role of the gut mucosa?

Answer 2

• Nutrient absorption
• Production of digestion enzymes
• Physical barrier
• Chemical barrier

Question 3

List the enzymes that enterocytes produce to aid digestion.

Answer 3

1. Maltase - digest maltose to 2 glucose
2. Sucrase - digest sucrose to glucose and fructose
3. Lactase - digest lactose to glucose and galactose
4. Lipase (intestinal) - digest fats into fatty acids and glycerol
5. Peptidases (intestinal) - digest peptides to amino acids

Question 4

What makes up the physical barrier of the gut that protects it?

Answer 4

1. Mucus
2. Glycocalyx
3. Cell monolayer

Question 5

What is the Glycocalyx (part of the physical barrier of the gut)?

Answer 5

Meshwork of glycoprotein and glycolipid molecules

Question 6

How does the glycocalyx protect the gut?

Answer 6

1. Interact with pathogens to prevent them from invading
2. Interact with commensal organisms resulting in a change in the glycocalyx

Question 7

What does the cell monolayer of the gut (ie enterocyte monolayer) do?

Answer 7

Regulated to allow permeability

Question 8

The enterocyte monolayer is held together by _____ called _____.

Answer 8

The enterocyte monolayer is held together by specialised proteins (tight junctions) called claudins, occludin and junctional adhesions (JAM).