1 - Overview Of GI Tract

Question 1

The GI tract adds …

Answer 1

water, ions, enzymes to a meal to create an AQUEOUS solution of molecules suitable for absorption and transport around the body

Question 2

How much fluid enters the upper gastrointenstinal tract each day?

Answer 2

8.5L

Oral intake + salivary, gastric, billary, pancreatic secretions

Question 3

Daily faecal fluid excretion?

Answer 3

150mL

Question 4

Net absorption in upper GI?

Answer 4

8L

Question 5

Where does most of the net absorption occur?

Answer 5

Small bowel

Question 6

The colon is unable to absorb more than…

Answer 6

2-3L a day

Question 7

What are the broad implications of embryology of the gut?

Answer 7

1. the folding of the embryo to form the gut results in the gut exposed to the outside
2. Gut is derived from endoderm, from from part of the yolk sac (except oral cavity and anal canal)
3. Divided into for/mid/hindgut which has implications for pain referral patterns
4. Lined by epithelium - also derived from endoderm

Question 8

What is gut microbiology?

Answer 8

Gut commensal bacteria (10-100 trillion organisms)

Question 9

Are humans born with their gut microbiota?

Answer 9

No they are born germ free. Later the pattern of bacteria remains relatively fixed

Question 10

Purpose of gut microbiota/commensal bacteria?

Answer 10

The diversity is important for health. Bacteria contribute to “barrier” function of epithelium to prevent sepsis, IgA production, epitehlial gene expression, reinforces tight junctions

Question 11

What are the implications of normal bacteria flora?

Answer 11

1. Breakdown of products of bacterial metabolism
2. Imbalance post antibiotics
   3.