14. How The Gut Protects Itself

Question 1

What are some things that are damaging to the gut?

Answer 1

Acid/pepsin
Ingested drugs
Refluxed bile
Smoking
Microorganisms
Ischaemia
Food allergens

Question 2

What are some things that are protective in the gut?

Answer 2

Mucus/HCO3
Cell membrane
Cell migration and renewal
Mucosal blood flow
Prostaglandins
Immune system
Acid inhibition
Apoptosis

Question 3

How does the stomach protect itself from acid and proteolytic breakdown?

Answer 3

Secretion of mucus that traps water and bicarbonate - diffusion barrier for acid
Physical barrier over proteolytic attack
Cell surface has a diff phospholipid bilayer
Tight junctions between cells - slows acid diffusion - if they do diffuse then blood takes it away to help antioxidant function