GI Intro

Question 1

List 3 functions of the Mouth

Answer 1

• Physical food breakdown
• Initial digestive enzyme release
• Infection control

Question 2

List 3 functions of the Oesophagus

Answer 2

• Rapid bolus transport to stomach through thorax
• Prevents air from entering the GI tract (Via UOS)
• Prevents reflux into Oesophagus (Via LOS)

Question 3

List the Organs food passes through in order from mouth to anus

Answer 3

Mouth
Oesophagus
Stomach

Duodenum
Jejunum
Ileum

(Start of Jejunum is wider than end of Ileum)

Cecum 
Ascending Colon 
Transverse Colon
Descending Colon 
Sigmoid Colon 
Rectum 
Anus

Question 4

List 5 functions of Stomach

Answer 4

Storage 
Physical breakdown 
Chemical breakdown 
Infection control 
Intrinsic Factor secretion 
Digestion begins

Question 5

Differentiate between how Upper and Lower stomach physically breaks down food

Answer 5

Upper: Creates basal tone (Slow sustained contractions)

Lower: Powerful peristaltic contractions (Thicker muscle)

Question 6

What are 2 challenges of the GI’s ability to kill pathogens

Answer 6

Thin epithelia

Large SA

Question 7

Different regions of the GI use different types of movement to move food along.

List them

Answer 7

Peristalsis
Segmentation
Haustral shuttling
Mass movements

Question 8

List 2 functions of Duodenum

Answer 8

• Neutralisation/ osmotic stabilisation of Chyme (Via HCO3 rich secretions from Liver and Pancreas)
• Concluding digestion (Via Bile and Pancreatic secretions)

Question 9

List 2 functions of the Jejunum

Answer 9

• Final point of digestion

- Nutrient absorption (Many folds so very high SA)

Question 10

List 3 functions of the Ileum

Answer 10

• Water/ electrolyte absorption (Small amount in jejunum)
• Bile reabsorption
• B12 absorption

Question 11

List 2 functions of the Large Bowel

What do the bacteria living here use as fuel?

Answer 11

• Final H2O Absorption (Mostly in Small Intestine)
• Temporary Storage
  (Also does some bile reabsorption)

Short chain fatty acids made by body