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What mechanisms prevent gastric reflux?

Lower oesophageal sphincter (LES):

Usually closed, transiently relaxes to allow bolus through


Angle of His and mucosal flap valve, as well as the postero-lateral location of the fundus all prevent acid reaching the LES and refluxing


Right crus of diaphram acts as a sling around the oesophagus serving as an 'extrinsic' sphincter


The failure of anti-reflux mechanisms leads to what?

Prolonged contact of gastric juices with oesophageal mucosa

Gastro-oesophageal reflux disease and associated symptoms


What are the typical clinical features of Gastro-oesophageal reflux disease (GORD)? 


Worsens on lying down, bending over or drinking hot drinks


What investigations are indicated by a history that leads you to suspect GORD?

No investigations done in typical clinical presentations

Only if worrying symptoms, such as dysphagia or hiatus hernia are suspected

Endoscopic investigation in this case


What are some of the risk factors for GORD?

Pregnancy or obesity

Fat, Chocolate, Coffee or Alcohol

Large meals


Hiatus hernia


List lifestyle management techniques to prevent/treat GORD

Lose weight

Stop smoking

Reduce consumption of chocolate, coffee, alcohol, fatty foods


Outline the types of treatment available for GORD, including their mechanism and an examples of each type

Simple antacids:

Neutralises acid with a base

E.g. Calcium carbonate

Raft antacids (alginates):

Forms a protective raft that sits on top of stomach contents and prevents reflux

E.g. Gaviscon


Reduction of acid secretion by oxyntic cells

E.g. Omeprazole

H2 antagonists:

Blocks H2 receptor which reduces acid secretions

E.g. Ranitidine



What is a common complication of GORD?

Continual contact of gastric juices and oesophageal mucosa can lead to metaplastic change (Barrett's Oesophagus)


What is Gastritis?

Chronic or acute inflammation of the gastric mucosa


Differentiate acute and chronic gastritis


Infection with H. pylori

Inflammatory changes to mucosa leadsing to atrophy and metaplasia (possible cancer)


NSAIDs, Alcohol, Cocaine

Exfoliation of surface cells and decreased secretion of protective mucus


What are the common symptoms of gastritis?

Commonly asymptomatic

Symptoms when they appear include:

- Dyspepia (Pain/Discomfort)

- Nausea

- Vomiting

- Haematemesis

- Melena


Outline the complications of Gastritis

Increases risk of Peptic ulcer disease

Chronic gastritis can cause hypergastrinaemia due to increasing gastrin release from G cells, this in turn can lead to Duodenal ulceration (DU)

Chronic Antral H. Pylori gastritis can lead to Gastric cancer and mucosa associated lymphoid tissue lymphoma (MALT Lymphoma)


How is gastritis diagnosed?


Testing for H. Pylori

Blood test (Anaemia due to GI bleed)

Stool test (Blood due to GI bleed)


What types of drugs are used to treat gastritis?



H2 antagonists

General theme is reduction in acid secretion for promotion of healing


E.g. Clarithromycin/Amoxacillin

Treatment of H. Pylori infection



What is peptic ulcer disease?

A break in the superficial epithelial cells down to the muscularis mucosa of either stomach (GU) or duodenum (DU)



Where are peptic ulcers commonly found?


Lesser curvature and antrum


Duodenal cap


Outline the most common cause of peptic ulcer disease

Give statisitics


Inhibit prostaglandins and reduce production of unstirred layer of mucus

50% of patients with long term NSAIDs have mucosal damage

30% when endoscoped have petic ulcer(s)

5% are symptomatic

1-2% have complications such as GI bleed


What is the prevlance of the different forms of peptic ulcer disease and how do prevalence rates vary across ages and countries?

DU in 10% adult population

GU is 2-3x less common (3-5%)

Prevalence is lower among younger adults and higher in older

Developing countries have increasing prevalence of NSAID associated DU and decreasing prevalence of H. Pylori associated ulceration



What are the clinical features of Peptic ulcer disease?

Reccurent, burning epigastric pain:

Worse at night and when hungry in DU

Relieved by eating

Persistent severe pain:

Suggestive of penetrtion of ulcer into other organs

Back pain:

Suggests penetration of ulcer in posterior stomach

Nausea and vomitting:

Less common

Weight loss and anorexia:

GUs only

Sudden haematemesis:

Asymptomatic patients can suddenly present with haematemesis when a blood vessel is erroded


What are the common investigations for suspected Peptic ulcer disease?

Investigation of H. Pylori infection

In 55+ patients or those with alarming symptoms an endoscopy can be done to exclude cancer


How is peptic ulcer disease managed?

Triple therapy:


H2 antagonists

Antibiotics for H. Pylori (Clarithromycin/Amoxicillin)

If taking NSAIDs, review use and perhaps use alternatives


NSAIDs and PPIs used together if NSAIDs are long term


What are the complications of peptic ulcer disease?

Haemorrhage of blood vessels: 




More common in DUs, normally into peritoneal cavity

Gastric outlet obstruction:

Can be pre-pyloric, pyloric or duodenal

Occurs due to active ulcers w/oedema or due to healing of ulcer  with associated fibrosis/scarring

Normally presents as vomiting without pain


Describe H. pylori bacteria

Gram negatic, Aerobic


Urease producing

Found in the mucus layer of the stomach or adhered to gastric mucosa


What is the significance of H. pylori producing urease?

Urease produces ammonia and CO2


Used to neutralise surroundings and protect the bacterium

C13 Urea test:

C13 Urea can be ingested by the patient to test for H. Pylori infection

Urease breaks down C13 urea forming C13 CO2 which can be exhaled and detected


How does H. Pylori colonisation of the gastric mucosa cause disease?

Secretion of enzymes and other substances that damage mucosa:

Ammonia is toxic to epithelia

Vacuolating cytotoxin A disrupts tight junctions and leads to apoptosis


Inflammatory response to bacterium (Inflammatory cells and mediators)


What are some of the diseases caused by H. pylori infection?

Chronic gastritis

Peptic ulcer disease

Gastric Cancers

MALT lymphoma


How does H. pylori colonisation in different areas of the stomach affect clinical outcomes?

Antrum predominant colonisation:

DU risk

Antrum and body colonisation:

Largely asymptomatic

Body predominant:

GU and cancer risk



How is a bacterium implicated only in the colonisation of the stomach cause DU?

Antral H. pylori infection leads to hypergastrinaemia and hence increased acid production from oxyntic cells

Duodenal cap is inflammed and damaged by excess acid and metaplasia can occur

H. pylori colonises inflammed duodenal cap

Duodenal immune response leads to duodenitis and development of ulceration which is common intermittent


How can we test for H. pylori infection?

C13 Urea test

IgG serum levels


Gastric biopsy taken and H. pylori detected by histology and culture



How is H. pylori infection treated?

Same as Gastritis, GU or DU with H. pylori being the cause

PPI, H2 antagonist, Antibiotics (Clarithromycin/Amoxicillin)

90% successful in treatment of H. pylori


Outline the progression of H. pylori induced disease thus describing how it can lead to gastric carcinoma

Initial H pylori infection leads to chronic non-atrophic gastritis

Multifocal atrophy develops and leads to metaplasia of the underprotected mucosa

Dysplasia develops from metaplasia and progresses to carcinoma

Factors involved in progression:

H. pylori virulence factors

Virulence associated host gene polymorphisms (genetic predisposition)

Dietary and environmental factors alter progression


Why is gastric cancer a particulalry deadly cancer?

Mildly symptomatic/Asymptomatic until late stage

5-6th biggest cause of cancer death


Outline the mechanisms of drugs which reduce gastric acid production


Prevents H+ ions from being pumped into oxyntic cell canaliculi

H2 antagonists:

Removes amplification of the Gastrin/Ach signal for acid production


Describe the gross anatomy of the stomach

Expanded part of the GI tract between the oesophagus and the duodenum

2-3 litres in capacity

Resembles letter J

Position depends on posture, body shape, distention

5 parts:

- Body

- Cardia

- Fundus

- Pyloric canal

- Pyloric antrum

2 Curvatures, greater and lesser


Label the diagram

Horizontal boxes, top to bottom:

Cardiac notch of stomach






Diagonal boxes, left to right:

Lesser curvature

Greater curvaure


What are the sphincters of the stomach and where are thy found?

Inferior oesophageal sphincter:

Found immediately superior to Z-line

In horizonatal plane with xiphoid process to the left of T11

Pyloric sphincter:

At the pyloric end of the stomach


Describe the structure and function of the inferior oesophageal sphincter

Immediately superior to the Z-line the diaphragmatic musculature forms the oesophageal hiatus

This functions as a physiological sphincter

Contracts and relaxes to allow boluses to pass and prevent stomach contents from refluxing


What is the Z-line?

The line where oesophageal mucosa abruptly changes to gastric mucosa

This marks the boundaries of each structure


Describe the structure and function of the pyloric sphincter

Circular muscle coat at the end of the pyloric portion of the stomach is thickened to form an anatomical sphincter

Regulates the passage of chyme into the duodenum


Label the boxes

From top left clockwise:


Endothoracic fascia


Upper phrenico-oesophageal ligament

Endoabdominal fascia

Cardiac notch

Lower phrenico-oesophageal ligament

Cardiac orifice of stomach




Label the diagram

Top to bottom:

Pyloric canal

Pyloric orifice/sphincter



What features of the stomach are most clearly seen when empty?


Longitudinal folds in the gastric mucosa

Gastric canal:

Found on the lesser curvature, a canal between gastric folds that allows saliva and small amounts of chewed food to reach the pylorus


Label this diagram, answers given in columns

Column 1:

Gastric pit

Mucous epithelium

Lymph vessel

Lamina propria

Musc. Mucosa


Oblique muscle

Circular muscle

Longitudinal muscle


Column 2:

Gastric pit

Artery + Veins

Gastric gland

Myenteric plexus

Column 3:

Mucous cells


Pariteal cells

Chief cells

Smooth muscle cell

G cell


Outline how the stomach has regions that are histologically distinct from each other

Different zones carry different types of cells in their gastric pits


Only neck cells

Fundus and Body:

Neck cells

Parietal cells

Chief cells


Neck cells



Describe the greater omentum

Prominent, four layered peritoneal fold hanging like an apron from the greater curvature

After descending it folds back up and attaches to the anterior transverse colon and its mesentery


Describe the lesser omentum

Small, double layered peritoneal fold that connects the lesser curvature of the stomach and the proximal part of the duodenum to the liver

Also connects the stomach to the portal triad


Describe the epiploic foramen

Opening siutated posterior to the free edge of the lesser omentum (hepatoduodenal ligament)


Label the boxes

Top to botom, left to right:

Lesser omentum

Finger inserted into epiploic foramen

Greater omentum


What is the coeliac trunk?

Branch of the abdominal aorta at the level of T12

Gives rise to the splenic, left gastric and common hepatic arteries

Supplies blood to the liver, stomach, abdominal, oesophagus, spleen and the superior half of both the duodenum and the pancreas.


Label this diagram

Top left clockwise:

Left gastric artery

Oesophageal branch of left gastric

Aortic hiatus

Posterior gastric artery

Splenic artery

Short gastric arteries


Left gastro-omental artery

Abd. Aorta

Right gastro-omental artery

Superior pancreaticoduodenal artery

Supraduodenal artery

Gastroduodenal artery

Common hepatic artery

Right gastric artery

Hepatic artery proper

Cystic artery

Coeliac trunk


Describe the blood supply to the lesser and greater curvature and the fundus and body of the stomach

Lesser curvature:

Left gastric (branch of the coeliac trunk)

Right gastric (branch of the common hepatic)

Greater curvature:

Left gastro-omental (branch of the splenic)

Right gastro-omental (branch of the gastro-duodenal, in turn a branch of the common hepatic)

Fundus and body:

Posterior/small gastric arteries (branches of the splenic)


Label this diagram

Top left anti-clockwise:

Left gastric vein

Right gastric vein

Portal vein

Pre-pyloric vein

Pancreaticoduodenal vein

Right gastro-omental vein

Splenic vein

Left gastro-omental vein

Middle gastric vein

Short gastric vein