Extra Qs GI

Question 1

What are the functions of the stomach?

Answer 1

1.	What are the functions of the stomach?
Stores and mixes food
Regulates emptying into the duodenum
Kill microbes
Secrete proteases
Secrete intrinsic factor
Mucosal protection

Question 2

WHat does Acl act on?

Answer 2

Parietal cells

G cells

Question 3

What seretes somatostain, what does it do

Answer 3

D cells in pancreas
Delta cells in the pyloric antrum, the duodenum and the pancreatic islets

inhibits cells

Question 4

WHat do chief cells release>

Answer 4

pepsinogen and chymosin
-stain blue due to pepsinogen etc
pesinogen is converted to pepsin = protein digestion

Question 5

Name two enterogastrones

Answer 5

CCK, secretin

Question 6

How is fat digested and absorbed?

Answer 6

Pancreatic lipase and colipase digest the fats
Emulsifaction – breaks lipids into small fat droplet by contraction of stomach and small intestine and bile salts are the emulsifying agents that keep the droplets separated.
Pancreatic lipase breaks these emulsifaction droplets down into monoglycerides and fatty acids, these can then re-aggregate to form micelles.
Free fatty acids can diffuse into enterocytes when there is a diffusion gradient and form micelles.
Micelles continuously breakdown and reform, if there is a concentration gradient, free fatty acids diffuse into the enterocytes. In the enterocytes they combine with proteins to form chylomicrons. Chylomicrons can then enter the lymph

Question 7

How are carbohydrates absorbed in the Intestine?

Answer 7

1. Amylase and BB enzymes break down
2. Glucose and galactose are cotransported with sodium through SGCT1 into enterocyte
3. Fructose is transported in via GLUT5
4. GLUT2 into blood

Question 8

Histological feature of duodenum

Answer 8

Duodenum
Brunners glands – alkaline mucus secreting – neutralises chyme
)pinky, round

Question 9

Histological feature of ileum

Answer 9

Peyers matches - submucosa - lymoid (purple)
shorter vaso recta
more arcades
less pliace circularis

Question 10

How do NSAIDs cause gastric ulcers?

Answer 10

Cyclo oxygenase 1 stimlates prostaglandins which stimulates mucus secretion
NSAIDs inhibit cyclooxygenase 1
So reduced mucosal defence

Question 11

What layer of the GI tract houses pacemaker cells and what are they called?

Answer 11

Interstitial cells of cajal 
Muscularis propria (circular smooth muscle layer)

Question 12

Affect of GORD on oesophagus

Answer 12

Oesophagus may be affected by acid reflux

This causes the stratified squamous epithelium to change to simple cuboidal (metaplasia).

Question 13

What are the stages of the embryological development of the midgut?

Answer 13

Elongation of the midgut forming the primary intestinal loop
Umbilical herniation
Rotation
Retraction
Fixation