Gastro-Intestinal Diseases Flashcards
Definition of dysphagia
Difficulty swallowing
Definition of heartburn
Retrosternal burning, common symptom of acid reflux
Definition of dyspepsia
Range of symptoms referring to upper GI tract including nausea, heartburn, acidity and pain
Definition of flatulence
Passing excess wind (belching, abdominal distention or passing of flatus per rectum)
Definition of vomiting
Stimulation of vomiting centres in lateral reticular formation of medulla. Either from stimulation of chemoreceptor trigger zones in the floor of the 4th ventricle or vagal afferents from the gut.
Nausea and vomiting with pain indicative of
GI origin
Nausea and vomiting without pain indicative of and examples
non-GI origin. Eg, CNS disease (raised intracranial pressures), drugs (chemo) or metabolic agents (uraemia, diabetic ketoacidosis)
Definition of constipation
Mean infrequent passage of stools (<2 per week) or difficulty passage of hard stool
Definition of diarrhea
Increased amounts of loose stool (>250g/day)
Definition of steatorrhoea and cause
Increased passage of pale, bulky stools that contain fat. Indicative of fat malabsorption as a result of small bowel, pancreatic or biliary disease.
Valve between distal end of oesophagus and stomach. How this valve opens/closes. Failure of this valve to open and outcome
Cardiac sphincter. Normally closed. Opens shortly after swallowing. After propelling bolus through peristalsis, the wave shuts it and prevents reflex. Failure of cardiac sphincter to open is known as achalasia. Leads to an accumulation of food in the oesophagus.
4 secretions of the stomach
Gastrin, gastric juice, bile and intrinsic factor
What is absorbed in the stomach
Water, alcohol and aspirin
Relationship of gastrin and gastric juice. Sequence of events after secretion.
Gastrin released from gastric antrum (in response to presence of food) and from duodenum (in response to presence of chyme). Gastrin stimulates secretion of gastric juice.
Increased gastrin leads to increased gastric juice leads to increased pepsin, increased gastric motility, enhancing growth of gastric and duodenal mucosa
What causes stimulation of mucous
Mucosal irritation (mechanical or chemical)
Acid in lumen of stomach
Vagal and sympathetic stimulation
Importance of intrinsic factor
Aids absorption of vitamin B12 from distal ileum
What does gastric motility cause
Mixes stomach contents with gastric juice
Converts to semi-liquid chyme
Propels contents through the stomach and into duodenum
Bile produced, stored and secreted?
Produced in liver, stored and concentrated in gall bladder and released into duodenum
Where does the oesophagus enter the diaphragm
Right and left crus
Common symptoms of problems with the oesophagus
Cough/vomiting (if foods/liquids do not pass normally to the stomach, causing them to reflux back to the pharynx), pain (maybe from acid reflux or spasm) and dysphagia. Sometimes vomiting blood which is known as haematemesis.
Common diseases associated with the oesophagus
Achalasia pharyngeal pouches oesophageal web carcinoma of the oesophagus Peptic ulcer disease/reflux Oesophageal spasm
Anatomy of the pharynx
3 overlapping constrictor muscles: superior, middle and inferior
Inferior constrictors include cricopharyngeus and thyropharyngeus
Name and cause of potential weakness in the oesophagus. Clinical significance
Meeting point of the 2 parts of the inferior constrictor muscles (thyropharyngeus and cricopharyngeus). Called Killian’s dehiscence. Thyropharyngeus pushes food forwards towards stomach (propulsive) but cricopharyngeus acts like a sphicter (constricts normally but then relaxes). If cricopharyngeus fails to relax, a posterior mucosal herniation may occur via Killian’s dehiscence known as Zeneker’s diverticulum or pharyngeal pouch.
Muscles of the oesophagus
Nervous supply
Lining mucosa
Musculo-tendenous tube connecting pharynx to the stomach
Outer longitudinal muscle with an inner circular coat. Upper 1/3 of the oesophagus is striated
Middle 1/3 is mixed
Lower 1/3 is smooth muscle
Motor and sensory from Vagus nerve
Nerve plexi between outer longitudunal and inner circular muscle planes
Lining mucosa= stratified squamous non keratinising
Process of moving food from mouth to oesophagus and explanation
Initial phase of swallow is voluntary
Triggers peristaltic wave
Pushes food bolus to stomach
Stretching gut causes depolarization and propagates creating a wave of muscle relaxation and contraction known as peristalsis
Cardiac sphincter at gastro-oesophageal junction is weak (not a clearly defined anatomical feature- cannot be seen)
Differential diagnosis for pain in the oesophagus
Often poorly localised so can be confused with mediastinal structures (eg the heart)
Causes of dysphagia and examples
Intrinsic Lesion (foreign body, benign/malignant structure, oesophageal web or pharyngeal pouch) Neuromuscular Disorder (Stroke, Bulbar palsy) Motility Disorders (Achalasia, diabetes, scleroderma) Extrinsic lesion compressing the oesophagus (lymphadenopathy, tumours in the neck and mediastinum)
Pharyngeal Pouch definition and clinical features
Herniation of mucosa around Killian’s dehiscence. Pouch hangs down due to gravity and may appear as a swelling in lower neck, usually left sided.
Dysphagia
Undigested food may get regurtitated into mouth
Overflow into lungs may cause respiratory problems
Can go septic, toxic or regurgitate straight into the larynx
Fungal infection of oesophagus? Possible reason?
Candida oesophagitis. Immunocompromised, transplant patients, HIV infection, chemotherapy
Aetiology and pathophysiology of Achalasia
Unknown aetiology but
Loss of ganglia from the intramural plexus leading to failure of relaxation of the smooth muscle of the gastro-oesophageal sphincter
Functional obstruction to oesophageal emptying
Failure of peristalsis leads to progressive dilatation of the oesophagus
Clinical Features of achalasia
Dysphagia
Weight loss if late-stage disease
Retrosternal chest pain
Non-peristaltic contractions may occur
Regurgitation of undigested solids during or shortly after a meal
Respiratory problems sometimes as food or fluid is aspirated into the lungs
Investigations (and explanation of investigations) and Treatment for achalasia
Barium swallow with fluoroscopy and manometry
Fluoroscopy- continuous X ray image like an x ray movie
Manometry- catheter with pressure sensors placed through oesophagus into stomach to measure rhythmic muscle contractions that occur when you swallow
Calcium channel blockers to relax the sphincter (eg, nifedipine, amlodipine) Balloon dilatation (endoscope with a balloon at the end that dilates to open up cardiac sphincter) Cardiomyotomy (muscles of cardiac sphincter cut, allowing food and liquid to pass through to the stomach) Botulinum toxin injections (promote dilation of oesophagus)
Definition and aetiology of oesophageal spasm
Descriptive term for spasm due to a variety of causes
Attacks of dysphagia and pain
Causes include: Atypical achalasia Gastro-oesophageal reflux Motor disorders Symptomatic peristalsis Obstruction at the cardia Neuromuscular disorder
Distinguishing between oesophageal spasm and achalasia
Diagnosed by radiological appearance after a barium swallow or oesophageal manometry
Oesophageal spasm can lead to a corkscrew oesophagus appearance
Pain resembles reflux and heartburn
Regurgitation of meals from less time ago in oesophageal spasms as oesophagus can hold a lot less volume compared to achalasia
In what kind of patients is oesophageal web common, and why is it important despite being rare
Chronic anaemics, middle aged women
Premalignant
Clinical features of oesophageal web
Glossitis
Iron deficiency anaemia
Dysphagia
Koilonychia
How an oesophageal web forms and investigation(s)
Mucosa becomes atrophic (tired and wasted)
Fibrous structure forms at the upper end of the oesophagus
Forms a web, visible on barium swallow
Treatment of oesophageal web
Dilatation of the stricture and correction of the iron deficiency. Understand why pt is anaemic
Monitor for recurrence and malignant transformation
Aetiology of GORD
Multifactoral
Caused by:
Malfunctioning lower oesophageal sphincter (cardiac sphincter) with defective relaxation of the sphincter
Abnormal motility of the lower oesophageal body, resulting in deficient of intermittent inefficiency of peristalsis
Clinical features of GORD
symptoms after a meal reflux most commonly heart burn regurgitation nausea bloating
Investigations and tx of GORD
Endoscopy and barium swallow but both may appear normal in GORD
Protein pump inhibitors eg omeprazole
H2 antagonists eg ranitidine
Antacids to control predisposing factors
Relationship of GORD and peptic ulcer disease
GORD increases chances of peptic ulcer disease
H. Pylori infection not related to pathogenesis of GORD
Peptic Ulcer Disease definition and promoting factors (why these factors increase risk of peptic ulcer disease)
Failure of the cardiac sphincter
Leads to acid reflux in oesophagus
Decreased mucosal protection coat:
Smoking (decreased vasculation and mucosal impairment)
NSAIDs and Aspirin (block cyclooxygenase and prostaglandin production, impairing mucosal production)
Steriods (same)
H.pylori infection (colonises mucous)
Peptic v gastric ulcers
Peptic ulcers can affect oesophagus, stomach or duodenum (anywhere the acid can get to)
Gastric ulcers is in the stomach only
Clinical features of PUD
Pain Vomitting Haematemesis- blood with vomiting Ulcers with scarring Spasm
Likely sites for ulcers to appear in the upper GI tract
Lower oesophagus, lesser curve of stomach, first part of the duodenum
Investigtions and treatment of PUD
Barium meal and endoscopy
Endoscopy most reliable. Cells taken for biopsy and culture
Proton pump inhibitors eg omeprazole
H2 antagonists eg ranitidine
Control predisposing factors using antacids
Treatment of H.pylori infection
Surgery includes inspection/ligation of bleeding vessels, transfusion and repair but surgical tx declined recently
Tx for H.Pylori infection
Quadruple therapy
Proton pump inhibor eg omeprazole
Bismuth-based (pepto-bismol)
2 antibiotics (amoxicillin and clarithromycin)
How can peptic ulcer disease cause acute upper GI bleeding
PUD either leads to scarring (may lead to stricture or obstruction) or
Healing (local scarring healed by secondary intent)
If it spreads through the gut wall, perforation and bleeds
Complications of cardiac sphincter failure
Barett’s oesophagus, GORD, Achalasia, PUD