Upper GI inflammation

list some causes of upper GI inflammation

environmental

genetic

cell damage

hormones

list physical manifestations of upper GI inflammation

Abdominal pain

Weight loss

Diarrhoea

Dysphasia

Fatigue

Cancer

Ulceration

Vomiting blood

Anaemia

Vomiting

Nausea

Funny taste

Ulceration 

what is the epithelium of the stomach

simple columnar epithelia

what covers the internal surface of the stomach

mucous cells

what is the epithelium of the oesophagus

non keratinised stratified squamous

what are the main differences between the stomach and the oesophagus

stomach - mucous production, adequate gastric acid production

oesophagus - do not secrete mucous, specialised goblet cells secrete mucous, less protection against gastric acid and can be insufficient if excess acid in oesophagus

list the cells of the gastric glands

surface mucus cells

mucus neck cells

parietal cells

chief cells

G cells

D cells

what is the secretory product of surface mucus cells

mucin in an alkaline fluid

what is the secretory product of mucus neck cells

mucin in an acidic fluid

what is the secretory product of parietal cells

HCL and intrinsic factor

what is the secretory product of chief cells

pepsinogen and lipase

what is the secretory product of G cells

gastrin

what is the secretory product of D cells

somatostatin

what affect does gastrin have on enterochromaffin

enterochromaffin to produce histamine

what affect does gastrin have on parietal cells

to produce gastrin

what affect does Ach have on G cells

to produce gastrin

what affect does Ach have on parietal cells

to produce acid

what does somatostatin inhibit

ECL cell histamine secretion

how does histamine stimulate acid secretion

by acting on parietal cells via H2 receptors

by acting on D cell via H3 receptor to inhibit somatostatic production

what receptor is associated with parietal cells in acid production by histamine

H2 receptor

what receptor is associated with D cells cells in acid production by histamine

H3 receptor

what is the role of pepsin

breaks down protein to assist transit through stomach

what is the role of hydrochloric acid

kills bacteria, viruses, parasites

optimises pH for action of pepsin

what is the role of intrinsic factor

binds free vitamin b12 to be absorbed in terminal ileum

what is the role of mucin

helps provide protection from auto-digestion by acid and pepsin

list common upper GI inflammatory conditions

gastro-oesophageal reflux disease

gastritis

ulcers

what is gastro-oesopheal reflux disorder

reflux of acid contents

incompetent lower oesophageal sphincter

what is the problem with the cells in GORD

cells do not produce mucus so there is less protection against acid

what is the symptoms of GORD

burning radiation behind sternum

when is GORD worse

bending, lying, jumping

spicy food

carbonated drinks

alcohol

smoking

what are common associations with GORD

obesity, pregnancy and structural abnormality

what is eosinophilic oesophagitis

chronic, allergic inflammatory

eosinophils, inflammation, narrowing and food bolus obstruction

what are risk factors of eosinophilic oesophagitis

asthma, allergy, environmental dust, dander, pollen

what is gastritis and duodenitis

inflammation lining of stomach or duodenum

imbalance in mucosal protection factors

what may cause gastritis and duodenitis

stress, alcohol, drugs, H.pylori and bile

what is an ulcer caused by

breakdown in mucosal integrity - imbalance in mucosal protection

what is the metastatic cascade

a multistep cellular process for spread of cancer from primary site to other sites in the body

define metaplasia

cell change from one type to another

define dysplasia

cell proliferation leading to atypical cell production

how does chronic inflammation lead to gastric and oesophageal cancer

sustained tissue damage

damage in dived cell proliferation

tissue repair

what is barrett’s oesophagus

metaplasia

abnormal change in epithelium

stratified squamous to simple columnar

goblet cells

what are gastric conditions which can occur

H.pylori

intestinal metaplasia

atrophic gastritis

what is intestinal metaplasia

cellular change - small bowel - goblet cells

what is atrophic gastritis

chronic inflammation

loss of gastric gland cells

replaced by intestinal type epithelium

what are the two types of oesophageal cancer

squamous cell cancer and adenocarcinoma

where in the oesophagus would squamous cell cancer occur

upper 2/3

where in the oesophagus would adenocarcinoma occur

lower 1/3

risk factors for squamous cell cancer

smoking and alcohol

risk factors for adenocarcinoma

GORD and barrett’s

how does GORD become adenocarcinoma

GORD → metaplasia → low grade dysplasia → high grade dysplasia → adenocarcinoma

what risk factors make individuals more susceptible for gastric cancers

• H.Pylori

• Smoking

• Overweight or obese

• A diet high in smoked, pickled or salty foods

• Stomach surgery for an ulcer

• Epstein barr virus infection

• Genes

• Working in coal, metal, timber or rubber industries

• Exposure to asbestos

how does H pylori gastritis become adenocarcinoma

H pylori gastritis → intestinal metaplasia → low grade dysplasia → high grade dysplasia → adenocarcinoma

list 4 common drug treatments

H2 antagonists

proton pump inhibitors

alignate/antacid

antacids

what is the role of antacids

calcium carbonate which will neutralise, raise gastric pH and reduce pepsin activity

what are types of H2 antagonists

cimitidine and famotidine

what is the mechanism of H2 antagonists

they block histamine from binding to H2 receptors so will prevent the production of acid from parietal cells

what are types of proton pump inhibitors

omeprazole and lansoprazole

what is the mechanism of proton pump inhibitors

Proton pump (H+/K+-ATPase) is the FINAL step in the secretion of acid in the gastric lumen from parietal cells.

-Bind irreversibly to the proton pump (H+/K+ antiporter) in parietal cell to INHIBIT acid secretion

By BLOCKING the secretion of H+ ions from the cell into the lumen

patient presenting with; trachealisation of the oesophagus, large eosinophilic count, narrowing, food bolus obstruction. what is this

eosinophilic oesophagitis

what is the metastatic pathway for adenocarcinoma cause by H.Pylori

chronic gastritis → atrophic gastritis → intestinal metaplasia → low grade dysplasia → high grade dysplasia → adenocarcinoma

Endoscopy reveals a non-healing ulcerating mass along the lesser curvature of the gastric antrum. Biopsy demonstrates a poorly differentiated malignancy with abundant intracellular mucin that displaces the nucleus to the cell periphery. Which subtype of gastric cancer is characterized by this "signet ring" cell morphology?

diffuse type gastric adenocarcinoma

mechanism of action of antacids

Formation of a physical viscous "raft" barrier floating on top of gastric contents to prevent reflux, neutralise, raise gastric pH and reduce action of pepsin

mechanism of action of proton pump inhibitors

will bind irreversibly to the proton pump (H+/K+ antiporter) in the parietal cells which will block secretion of H+ ions into the lumen

list the three types of gastric cancer

adenocarcinoma

lymphoma

signet ring cell

where might gastric and oesophageal cancer metastasise to

lung, liver, bones, adrenal gland, brain, lymph nodes