The Stomach and Duodenum

Question 1

What are the four areas of the stomach?

Answer 1

Cardia
Fundus
Body
Antrum

Question 2

Where does the fundus lie?

Answer 2

Proximally, under the left diaphragm

Question 3

What does the antrum serve as?

Answer 3

A reservoir where food can be retained and broken up before being spelled into the small intestine

Question 4

What are the three layers of the stomach smooth muscle wall?

Answer 4

Outer longitudinal
Inner circular
Innermost oblique

Question 5

Which part of the stomach has thick folds or rugae?

Answer 5

The greater curvature

Question 6

Which cells are in the upper two thirds of the stomach?

Answer 6

Parietal cell

Chief cells

Question 7

What do parietal cells secrete?

Answer 7

HCl

Intrinsic factor

Question 8

What do chief cells secrete?

Answer 8

Pepsinogen

Question 9

Do HCl, intrinsic factor, gastrin and pepsinogen inhibit or stimulate acid production?

Answer 9

Stimulate

Question 10

Which cells are present in the antral mucosa of the stomach?

Answer 10

G and D cells

Question 11

What do G cells secrete?

Answer 11

Gastrin

Question 12

What do D cells secrete?

Answer 12

Somatostatin

Question 13

How do somatostatin, VIP and GIP affect acid sectretion?

Answer 13

Inhibits it

Question 14

What is the function of the mucosal barrier?

Answer 14

To protect gastric epithelium from damage.

Question 15

What is the function of prostaglandins?

Answer 15

Stimulate the production of mucus

Question 16

Which substances inhibit prostaglandins to inhibit the production of mucus?

Answer 16

Aspirin

NSAIDs

Question 17

Where are Brunner’s glands located?

Answer 17

Duodenum

Question 18

What is the function of Brunner’s glands?

Answer 18

They secrete alkaline mucous to help neutralise acid secretion along with pancreatic and biliary secretions

Question 19

Which nerve supplies the stomach?

Answer 19

The nerve of Laterjet

Question 20

What are the three phases of acid secretion?

Answer 20

Cephalic
Gastric
Intestinal

Question 21

What is the cephalic phase of acid secretion?

Answer 21

The thought, signs and smell of food stimulate the vagus, producing ACh

Question 22

What is the gastric phase of acid secretion?

Answer 22

Distension by food activates mechanoreceptors and directly stimulates secretory cells and gastrin release

Question 23

What is the intestinal phase of acid secretion?

Answer 23

The passage of food into the duodenum inhibits gastric secretion

Question 24

How does histamine increase acid secretion?

Answer 24

Stimulates the Gs (gastrin stimulating) protein via the H2 receptors and acts via cAMP to increase acid secretion

Question 25

How does prostaglandin E2 inhibit acid secretion?

Answer 25

Activates the Gi (gastrin inhibiting) protein to inhibit acid secretion

Question 26

How does ACh increase acid secretion?

Answer 26

Acts via the vagus M3 receptors and also via the enterochromaffin cells to increase acid secretion

Question 27

How does gastrin increase acid secretion?

Answer 27

Acts via the cholecystokinin B gastrin receptor, increasing intracellular free calcium. Also acts via the enterochromaffic-like cells, stimulating histamine to increase acid secretion

Question 28

What is gastritis?

Answer 28

The term used to indicate inflammation associated with mucosal injury

Question 29

What is gastropathy?

Answer 29

The term used to describe epithelial cell damage and regeneration without inflammation

Question 30

What are the causes of gastritis?

Answer 30

``` H. pylori (commonest) Autoimmune gastritis Viruses (CMV, HSV) Duodeno-gastric reflux Specific causes e.g. Crohn's ```

Question 31

What can chronic inflammation of the gastric mucosa cause?

Answer 31

Gastric intestinal metaplasia, a pre-cursor to gastric cancer

Question 32

Where does autoimmune gastritis affect, and what does this lead to?

Answer 32

Affects the fundus and body. | This leads to atrophic gastritis and loss of parietal cells

Question 33

What cause the clinical syndrome of pernicious anaemia in autoimmune gastritis?

Answer 33

Rhydria and intrinsic factor deficiency

Question 34

What is gastropathy usually caused by?

Answer 34

Irritants (drugs, NSAIDs, alcohol) Bile reflux Chronic congestion

Question 35

When can acute erosive or heaemorrhagic gastropathy be seen?

Answer 35

After severe stress (stress ulcers) Secondary to burns, trauma, shock or renal failure In portal hypertension (portal gastropathy)