Session 4- Stomach

Question 1

What allows the stomach to maintain a similar pressure despite changes in volume with food?

Answer 1

Rugae, allow stomach to expand

Question 2

What are the main functions of the stomach?

Answer 2

Temporary storage, digestion, mechanical breakdown, innate immunity

Question 3

What are rugae in the stomach?

Answer 3

Temporary folds within the stomach mucosa

Question 4

What are the cells found within the gastric glands?

Answer 4

Chief, parietal, enteroendocrine cells

Question 5

What is the function of gastrin and where is it released?

Answer 5

Released from G cells. Stimulates acid production

Question 6

What is the function of intrinsic factor and where is it produced?

Answer 6

Produced in parietal cells in stomach, it helps with absorption of vitamin B12 in ileum

Question 7

What is the function of pepsinogen and where is it produced?

Answer 7

Inactivate form of pepsin which is a protease, produced by chief cells

Question 8

What are the sections of the stomach?

Answer 8

The fundus, corpus (body), antrum

Question 9

How does stomach acid help with the digestion of proteins?

Answer 9

The acid unravel proteins increasing the surface area for enzymes to act on

Question 10

Where is the greatest number of G cells found within the stomach?

Answer 10

In the pyloric antrum

Question 11

What are the three layers of muscles in the stomach?

Answer 11

The oblique, circular and longitudinal layers

Question 12

What do the ECL cells secrete in response to gastrin?

Answer 12

Histamine

Question 13

What effect does histamine from ECL cells have?

Answer 13

Stimulates parietal cells to produce more acid

Question 14

What do D-cells produce?

Answer 14

Secretin

Question 15

What effect does secretin have on acid production?

Answer 15

Reduces acid production

Question 16

What are D cells sensitive to?

Answer 16

Low pH

Question 17

How do prostaglandins help protect the stomach?

Answer 17

Increase blood flow and support mucus

Question 18

How does stomach protect itself?

Answer 18

Mucus with carbonate ions from epithelia, good blood flow, quick turnover of epithelia

Question 19

What helps prevent reflux?

Answer 19

The lower oesophageal sphincter, angle of entry of oesophagus into stomach

Question 20

What three things that stimulate parietal cells to produce stomach acid?

Answer 20

Gastrin, histamine and Ach

Question 21

Through what receptor does gastrin bind to on parietal cells?

Answer 21

Cholecystokinin receptors

Question 22

What receptors on parietal cells does Ach bind to?

Answer 22

Muscarinic receptors

Question 23

Why is that stomach acid production increases when amino acids/peptides are detected in the stomach and when the stomach is distended?

Answer 23

Amino acids: G cells detect these and release gastrin which acts on CCK receptors on parietal cells
Distentension: stretch is detected by vagus nerve causing Ach to bind to muscarinic receptors on parietal cells

Question 24

What are the three stages of digestion?

Answer 24

Cephalic, gastric, intestinal

Question 25

What are the most common pathologies of the stomach?

Answer 25

GORD, gastritis, peptic ulcer disease and cancer

Question 26

What is the term dyspepsia used to describe?

Answer 26

Upper GI tract symptoms lasting over four weeks, including: upper abdominal pain/discomfort, heartburn, acid reflux, nausea/vomiting

Question 27

What are four common triggers/causes for GORD?

Answer 27

Altered LOS function, delayed gastric emptying, obesity, pregnancy

Question 28

What is Barrett’s oesophagus?

Answer 28

Metaplasia of oesophageal epithelia from acid reflux

Question 29

What is gastritis?

Answer 29

Inflammation of the stomachs mucosal layer

Question 30

What can cause acute gastritis?

Answer 30

Excessive alcohol consumption or NSAID use

Question 31

What is the most common cause of chronic gastritis?

Answer 31

H-pylori infection

Question 32

How does H-pylori infection cause damage to the stomach lining?

Answer 32

Breaks down urea into CO2 and ammonia, ammonia being toxic to cells

Question 33

What is peptic ulcer disease?

Answer 33

A breach in the gastric or duodenal membrane passing through the muscularis mucosa

Question 34

Are gastric or duodenal ulcers more common?

Answer 34

Duodenal

Question 35

How would you treat a patient with a symptomatic H-pylori infection?

Answer 35

Treatment program involving two antibiotics and a proton pump inhibitor

Question 36

How is a h-pyloric infection investigated?

Answer 36

Urea breath test, stool antigen test, blood test

Question 37

What are the intrinsic and extrinsic parts of the lower oesophageal sphincter?

Answer 37

Intrinsic is smooth muscle within the stomach, extrinsic comes from the crux of the right part of the diaphragm

Question 38

What is receptive relaxation?

Answer 38

As peristalsis occurs in the oesophagus this alerts the stomach to incoming food and so the fundus of the stomach relaxes and distends

Question 39

What drugs can be used to reduce acids secretion?

Answer 39

Proton pump inhibitors and H2 receptor inhibitors

Question 40

What can be a complication of a peptic ulcer?

Answer 40

Erosion through the stomach lining causing peritonitis, or erosion through to an artery causing a bleed