GI Medicine Flashcards
Upper GI disease
-Gastro-Oesophageal Reflux Disease (GORD)
-Peptic Ulcer Disease (PUD)
What are the components of the Upper GI tract?
Mouth
Pharynx
Oesophagus
Stomach
Small intestine (duodenum)
Function of GI tract
Ingestion of food
Digestion of food
Nutrient absorption
Anal canal
What are the components of the Lower GI tract?
Small intestine (jejunum, ileum)
Colon (caecum, ascending, transverse, descending, sigmoid)
Rectum
Anus
Which parts of the GI tract are involved in the ingestion of food?
Mouth and pharynx.
What components aid in the digestion of food in the GI tract?
Teeth, saliva, stomach acid, stomach enzymes, bile, and pancreatic enzymes.
Where does nutrient absorption occur in the GI tract?
Small intestine and colon.
What part of the GI tract is responsible for excretion of waste products?
Anal canal.
What are the four layers of the GI tract?
Mucosa, submucosa, muscularis externa, and adventitia/serosa.
What is the fibromuscular tube in the GI tract that transports food from the pharynx to the stomach?
Oesophagus
What process moves food through the oesophagus to the stomach?
Peristalsis
What is the function of sphincters in the GI tract?
To prevent the reflux of the food bolus and stomach contents.
What are the two types of digestion that occur in the stomach?
Chemical digestion (HCl acid, pepsin, lipase) and mechanical digestion.
What substances are absorbed by the stomach?
Vitamin B12 (via parietal cells), alcohol, and water.
Which endocrine hormones are secreted by the stomach, and what are their functions?
-Gastrin (stimulates HCl secretion)
-CCK (stimulates the gall bladder).
What do chief cells in the stomach produce?
Pepsin
What do parietal cells in the stomach produce?
HCl and intrinsic factor
What is the function of mucus cells in the stomach?
Mucus
What does GORD stand for?
Gastro-oesophageal reflux disease
What percentage of the population is affected by GORD?
10-30%
What happens in GORD?
Acid and stomach contents flow through the lower oesophageal sphincter (LOS) into the oesophagus.
What are the causes of GORD?
Laxity of LOS)
Increased gastric pressure
Delayed gastric emptying
What are the consequences of gastric acid irritating the oesophageal mucosa?
-Symptoms of irritation
-Metaplasia of oesophageal epithelium (Barrett’s oesophagus, a precancerous condition)
What are the common symptoms/signs of GORD?
Dyspepsia (indigestion or “heartburn”)
Epigastric pain
Bloating
Nausea/vomiting
Vocal hoarseness
Dental erosion
What are the risk factors for GORD?
Stress and anxiety
Smoking
Alcohol consumption
Trigger foods (e.g., coffee, chocolate, fatty meals)
Obesity
NSAIDs (non-steroidal anti-inflammatory drugs)
Pregnancy
Lying flat after a large meal
What are the management strategies for upper GI conditions?
-Lifestyle changes:
Weight loss
Stopping smoking
Reducing alcohol
Eating smaller meals
-Medications:
Antacids
Proton pump inhibitors (e.g., omeprazole)
H2 receptor antagonists (e.g., ranitidine)
Surgery in extreme cases
What are the red flag features in GI disease that warrant a GP referral for upper GI endoscopy (OGD)?
Unexplained weight loss
Loss of appetite
Dysphagia (difficulty swallowing)
Vomiting blood
Rectal bleeding or blood in stool
Unexplained iron deficiency anaemia
What is the role of antacids in the medical management of GORD, and how do they work?
Role: Provides symptomatic relief.
Mechanism: Creates a foam on the surface of gastric acid and neutralizes pH.
Example: Gaviscon.
How do proton pump inhibitors (PPIs) work in the treatment of GORD?
Mechanism: Inhibit the proton pump (H⁺) of parietal cells, reducing the production of HCl (gastric acid).
Examples: Omeprazole, lansoprazole.
What is the mechanism of action of H2 receptor antagonists in managing GORD?
Mechanism: Bind to H2 receptors on parietal cells, preventing the binding of histamine and the stimulation of parietal cells to produce gastric acid.
Examples: Ranitidine, famotidine.
What is Barrett’s oesophagus, and what are its causes and risks?
Definition: A complication of GORD involving metaplasia of the oesophageal epithelium at the gastro-oesophageal junction.
Cause: Prolonged exposure to gastric acid, leading to the transformation of squamous epithelium into columnar epithelium.
Risk: Malignant potential, increasing the risk of oesophageal adenocarcinoma.
What are the dental implications of GORD?
Erosion:
Acid softens tooth structure and causes loss of tooth tissue.
Affects palatal and labial aspects of upper teeth and occlusal surfaces of lower teeth.
Restorations may “stand proud” due to surrounding tooth erosion.
Symptoms:
Burning mouth symptoms.
Taste disturbance (dysgeusia).
Significance:
Dentists may be the first to detect GORD through these oral signs.
What are the two main types of oesophageal cancer, and what are their causes?
Upper 2/3 of oesophagus: Squamous cell carcinoma
Risk factors: Smoking and alcohol.
Lower 1/3 of oesophagus: Adenocarcinoma
Associated with Barrett
What is peptic ulcer disease and how does it occur?
Definition: Ulceration of the mucosa in the stomach, duodenum, or oesophagus (rarer).
Cause: Lack of mucus production disrupts the protective coating against gastric juices (acidic), leading to mucosal damage.
What are the key risk factors for peptic ulcer disease that disrupt the mucus barrier?
NSAIDs (due to topical effects and COX-1 inhibition).
Helicobacter pylori infection.
What are the risk factors for increased stomach acid production in peptic ulcer disease?
Stress.
Caffeine.
Smoking and alcohol.
Spicy foods.