Upper GI Inflammation

Question 1

what are the causes of upper GI inflammation?

Answer 1

environmental (smoking, chemicals, drugs, viruses, bacteria)
hormonal secretion
genetic
host immunity

Question 2

what are the outcomes of GI inflammation?

Answer 2

imbalance in mucosal protection
cell damage & metaplasia (abnormal turnover)
inflammation/irritation

Question 3

what are the physical manifestations of upper GI inflammation?

Answer 3

abdominal pain
weight loss
diarrhoea
dysphagia (stuck food feeling)
fatigue
vomiting (possibly blood)
anaemia
nausea
ulceration

Question 4

describe the cellular function of the stomach

Answer 4

simple columnar epithelium
all cells contribute to mucous secretion (covers most of internal surface)
adequate gastric acid protection

Question 5

describe the cellular function of the oesophagus

Answer 5

non-keratinised stratified squamous epithelium
no mucous decretion unless goblet cell
less protection againest gastric acid

Question 6

name the cells of gastric glands and their secretory products

Answer 6

surface mucous - mucin (alkaline fluid)
mucous neck - mucin (acidic fluid)
parietal cells - HCl/intrinsic factor
chief cells - pepsinogen/lipase
G cells (enteroendocrine) - gastrin
D cells (pyloric region) - somatostatin

Question 7

what does gastrin stimulate?

Answer 7

enterochromaffin like cell (ECL) to produce histamine
parietal cells to produce acid

Question 8

what does acetylcholine stimulate in the stomach?

Answer 8

G cells - gastrin
parietal cells - HCl

Question 9

what does somatostatin inhibit?

Answer 9

ECL - histamine

Question 10

what does histamine stimulate in the stomach?

Answer 10

HCl - parietal cells (H2 receptor)
HCl - D cell (H3 receptor) to inhibit somatostatin

Question 11

what is the function of intrinsic factor in the stomach?

Answer 11

binds free vitamin B12 to be absorbed in terminal ileum

Question 12

what is the function of HCl in the stomach?

Answer 12

pH 0.8
kills bacteria/viruses/parasites
optimises pH for pepsin action

Question 13

what is the function of mucin in the stomach?

Answer 13

helps provide protection from auto-digestion by acid and pepsin

Question 14

explain the physiology of GORD

Answer 14

reflux of acidic stomach content
incompetent lower oesophageal sphincter

Question 15

what are the symptoms and exacerbation factors of GORD?

Answer 15

symptoms - burning, radiation behind sternum
exacerbation factors - bending/jumping/lying

Question 16

what are the generalised risk factors for GORD

Answer 16

spicy food/carbonated drink/alcohol consumption
smoking
obesity
pregnancy
structural abnormality
dysphagia

Question 17

what is eosinophilic oesophagitis and what are the risk factors?

Answer 17

chronic allergic inflammation of the oesophagus

RF - asthma, allergies, environmental factors

Question 18

what is gastritis/duodenitis and what are the risk factors?

Answer 18

inflammation of the stomach/duodenal lining (dyspepsia)
imbalance in mucosal protection factors

RF - stress, alcohol, drugs, H.Pylori, bile

Question 19

explain antacids

Answer 19

calcium carbonate - neutralisation action
raises gastric pH, reduces pepsin activity

Question 20

explain alignate/antacid dual medication

Answer 20

raft barrier - gel like block preventing stomach content reaching oesophagus
raises pH

Question 21

explain H2 antagonists

Answer 21

cimitidine/famotidine
reduces stomach acid production by reversibly inhibiting histamine binding

Question 22

explain proton pump inhibitors

Answer 22

omeprazole, lansoprazole
binds irreversibly to H+/K+ proton pump in parietal cells to inhibit acid secretion (blocks H+ ions entering lumen from cell)

Question 23

explain the gastric/oesophageal pre-cancerous cascade

Answer 23

chronic inflammation
sustained tissue damage
damage induced cell proliferation
metaplasia (cell changing types)
dysplasia (cell proliferation with atypical cell production)
cancer

Question 24

describe the common oesophageal pre-malignant change

Answer 24

barret’s oesophagus:
- abnormal cell change in epithelium
- stratified squamous -> simple columnar
- chronic acid damage
can become barret’s metaplasia/adenocarcinoma

Question 25

what are some of the factors/signs of gastric cancer?

Answer 25

H.Pylori bacteria (gram -ve) cellular change (small bowel/goblet cells) atrophic gastritis (chronic inflammation, loss of gastric gland cells and rugae, replaced by intestinal type epithelium)

Question 26

what cancer is most common in the oesophagus and what are the common risk factors?

Answer 26

upper 2/3 - squamous cell cancer (smoking/alcohol) lower 1/3 - adenocarcinoma (GORD/Barret's)

Question 27

what are the common metastasis sites of oesophageal and stomach cancer?

Answer 27

lymph nodes lung liver bones adrenal glands brain

Question 28

what are the stages of the metatstatic cascade in oesophageal and stomach cancers?

Answer 28

risk factor (GORD, gastritis, H.Pylori) metaplasia low grade dysplasia high grade dysplasia adenocarcinoma/cancer

Question 29

what are the common types of stomach cancer?

Answer 29

adenocarcinoma (stomach folds) signet ring cell lymphoma

Question 30

what are the risk factors for stomach cancer?

Answer 30

H.Pylori smoking obesity diet heavy in smoked/pickled/salty foods stomach surgery (ulcer) epstein-barr virus infection genetics industry work (coal/metal/timber/rubber/asbestos exposure)