Pathophysiology Of Gastric Disease Flashcards
What is Zollinger-Ellison syndrome?
Very rare
Gastrin secreting tumour of the pancreas
Acid production increased
Nasty erosions
Define GORD and symptoms
Gastro-oesophageal reflux disease
Reflux of stomach contents
Damages mucosa
Sx = heartburn, cough, sore throat, dysphagia
Why might GORD cause dysphagia?
Strictures formed in the oesophagus due to the damage to the mucosa
What are some causes of GORD?
Lower oesophageal sphincter problems
Delayed gastric emptying (often in diabetes)
Hiatus hernia
Obesity (increased abdo pressure)
Describe a hiatus hernia
LOS problem
Stomach herniates through into thorax
Easier to reflux
What metaplasia occurs in Barrett’s oesophagus?
Stratified squamous to simple columnar
What are the treatments for GORD?
Life style modifications (diet, smaller meals)
Pharmacological - antacids, PPIs, H2 antagonists
Surgery (rare)
Describe what happens in acute gastritis and some of the causes
Inflammation of the mucosal lining
< few weeks
Due to: heavy use of NSAIDs, lots of alcohol, chemotherapy or bile reflux
(Things that break down the normal protective mechanisms)
How can chemotherapy lead to acute gastritis?
Decrease the turnover rate of cells
Cannot shed stomach lining as quickly
What are the Sx of acute gastritis?
Pain
Nausea
Vomiting
(Occasionally bleeding)
What are the common causes of chronic gastritis?
Bacterial - H. Pylori infection (most common)
Autoimmune - antibodies to parietal cells
Chemical/reactive - chronic alcohol abuse, NSAIDs, bile reflux
How can autoimmune causes of gastritis lead to pernicious anaemia?
Damage to parietal cells
Intrinsic factor not released
Cannot absorb vit B12
Vit B12 deficiency -> pernicious anaemia
What are the Sx of H. Pylori causing chronic gastritis?
Asymptomatic or similar to acute gastritis
Sx may develop due to complications
What are the Sx of an autoimmune chronic gastritis?
Anaemia
Glossitis (inflammation of tongue)
Anorexia (decreased appetite)
Neurological Sx
To be classed as an ulceration, which layer must it extend through?
Muscularis mucosa
Where is the most common place to get a peptic ulcer?
1st part of the duodenum
Why is the 1st part of the duodenum exposed to ulcers?
Very acidic chyme coming out of the stomach
Often not neutralised fast enough
Describe the problems with the physiology that can lead to ulcers
Decreased mucus Decreased HCO3- Decreased blood flow Decreased prostaglandins Decreased epithelial renewal
Describe the common Sx of peptic ulcers
Epigastric pain (foregut)
Burning/gnawing pain
Follows meal times (worse with acid release)
Often at night (esp duodenal)
Describe the Sx of a very serious peptic ulcer
Normal Sx plus: Bleeding - vomiting Anaemia Satiety Weight loss
What is functional dyspepsia?
Having symptoms of ulcer disease with no physical evidence of the disease
Common
Diagnosis of exclusion
How do we diagnose gastric pathologies?
Upper GI endoscopy Biopsy - benign/malignant Urease breath test - H. Pylori Erect chest x-ray - perforations Blood test - anaemia
How does H. Pylori survive the harsh environment of the stomach?
Uses urease to breakdown urea into ammonia
Creates a cloud of increased pH around itself to protect from the acid conditions
How do we eradicate H. Pylori?
Triple therapy
PPI + clarithomycin + amoxicillin
How is H. Pylori spread?
Oral-oral
Faecal-oral
Describe some features of H.pylori
Helix shaped Gram negative Aerobic (only needs a small amount) Produces urease Flagellum - good motility
What are the problems with having H.pylori present in the stomach?
Release of cytotoxins - direct epithelial injury
Express enzymes - ammonia is toxic to epithelia
Possible degrades mucus layer
Promotes inflammatory response - self injury
(Breakdown of the protective barrier)
Where is the majority of H.pylori colonisation?
Antrum (and body)
To cause a stomach ulcer, H.pylori would commonly colonise where?
Body
What problems can occur as a result of Zollinger-Ellison syndrome?
Proliferation of parietal cells - increased acid
Severe ulceration of stomach/small bowel
Abdominal pain
Diarrhoea
Stress ulceration of the stomach give occur following these massive physiological stresses:
Severe burns Increased intracranial pressure Sepsis Severe trauma Multiple organ failure
How common is stomach cancer?
3rd most common cancer in the world
Name some Sx that can occur with stomach cancer
Dysphagia Loss of appetite Malaena Weight loss Nausea/vomiting Virchow's nodes
Give some major risk factors for getting stomach cancer
Male
H.pylori
Diet (high salt)
Smoking
What are the 2 types of adenocarcinoma?
Intestinal
Diffuse
What do we do to diagnose stomach cancer?
Bloods
Upper GI endoscopy - visualise and biopsy
CT scan - staging
