Lab 1: Presentation 2 Flashcards
Define gastro-oesphageal reflux disease
Defined as the gastric acid from the stomach refluxes through the lower oesophageal sphincter and irritates the lining of the oesophagus.
Why is the oesphageal more sensitive to gastric acid than the stomach is?
The oesophagus has a squamous epithelial lining making it more sensitive to the effects of stomach acid.
The stomach has a columnar epithelial lining that is more protected against stomach acid.
What are the most common symptoms for gastro-oesphageal reflux disease
- Heartburn
- Acid regurgitation
- Retrosternal or epigastric pain
- Bloating
- Nocturnal cough
- Hoarse voice
The oesphageal is a 25cm muscular tube that connects from the ___ to the ____
A) Pharynx
B) Stomach
What are the layers that make up the wall of the oesphagus
- Mucosa (innermost)
- Submucosa
- Muscular external
- Circular
- Longitudinal
- Adventitia/Serosa
Where does the pharynx become continous with the oesphagus
At the level of C6 vertebrae
The oesphagus passes through the ____ of the diaphragm
Right crus
What anatomical and physiological arrangements protect against gastro-oesphageal reflux?
- Presence of the lower oesphageal sphincter (physiological sphincter)
- The angle between the oesphagus and the cardia of the stomach (Angle of His)
- The crura of the diaphragm surrounding the oesphagus
- Peristalsis of the oesphageal and stomach
What is a hiatus hernia?
This is when the upper part of the stomach protrudes through the diaphragm into the thoracic cavity
Which cells (between chief and parietal cells) lies more superior in the gastric gland
Parietal cells lies closer to the enterance of the gastric gland in comparison to the Chief cells
Which cell type in the gastric mucosa secretes intrinsic factor
Parietal cell
Why is intrinsic factor important?
It binds to vitamin B12 and allows it to be absorbed from the ileum
What type of epithelium lines the oesphagus?
Stratified squamous non-keratinised epithelium
What is “metaplasia”
The change in the cells from one form to another
What is the mechanism of action for omeprazole
Proton pump inhibitor
What is the mechanims of action for Cimetidine
H2 receptor antagonist
Name drugs that can be used to manage a patient with gastro-oesphageal reflux disease
- Omeprazole
- Cimetidine
- Gavison
- Aluminium hydroxide
What is the mechanism of action for Alginate Antacid?
e.g. peptac/gavison
Forms a “raft” that floats on the surface of stomach contents to reduce reflux
What is the mechanism of action ofr aluminium hydroxide?
Acts by binding to free H+ ions
The oesphagus is located ___ to the trachea
Posterior
The muscularis externa of the oesphagus contains two types of muscle fibres. Name them?
Skeletal and smooth muscle fibres
Name the two types of hiatus hernia
Sliding and rolling
Describe the difference between a sliding hiatus hernia and a rolling hiatus hernia
A sliding HH is where the gastro-oesphageal junction slides up into the thorax.
A rolling HH is where the gastric fundus protudes up alongisde the gastro-oesphageal junction
Name some of the red flag symptoms of a GI investigation
- Unexplained weight loss
- Dysphagia (swallowing difficulties)
- Persistent vomiting
- GI blood loss
- Upper abdominal mass
Describe the mechanism of oesphageal phase of swallowing
- Food bolus pushed up against soft palate and into pharynx
- Upper oesphageal sphincter relaxes, respiration pauses, glottis closed- food enters the oesphagus
- Primary peristaltic wave propels bolus towards stomach
- Lower oesphageal sphincter opens at initiation of swallow- food enters the stomach
- Secondary peristalsis occurs locally in response to distension (if food is left over in the oesphagus) - this is a stronger wave-like contraction
What are possible causes for dysphagia?
Intrinsic causes: foreign body, tumours etc
Extrinsic causes: pressure from lymph nodes
Motility disorders: achalasia, oesphageal spasm
Neuromuscular disorders: cerebrovascular diseaes
What does dysphagia mean
Swallowing difficulties
Describe achalasia
A condition in which the lower oesphageal sphincter fails to relax during swallowing
As a result, the bolus fails to pass from the oesphagus into the stomach
Due to damage in the myenteric plexus in the lower two thirds of the oesphagus- therefore this region remains spastically contracted
Can lead to infections and enlargement of the eosphagus
Describe Barrett’s oesphagus
Constant reflux of acid results in the lower oesophageal epithelium changing in a process known as metaplasia from a squamous to a columnar epithelium. This change to columnar epithelium is called Barretts oesophagus.
When this change happens patients typically get an improvement in reflux symptoms.
Describe oesphagitis
Inflammation of the squamous mucosa secondary to acid damage.
Can cuse strictures (narrowing of the oesphagus)
Barretts oesophagus is a risk factor for the development into?
Adenocarcinoma (maligant tumour of the oesphagus- high mortality rate)
Oesophagitis is a risk factor for the development into?
Barrett’s oesphagus (metaphasic changes in the epithelium) if chronic exposure of the oesphagus to gastric acid
What are the complications of acid reflux?
- Oesphagitis - inflammation causing a narrowing of the oesphagus
- Barrett’s oesphagus- metaphasic change from stratified sqamous non-keratinised epithelium to mucus-secreting columnar epithelium - often premalignant
- Adenocarcinoma- malignant tumour of the oesphagus- high mortality rate
This image is an example of which condition of the oesphagus
Barrett’s oesphagus
Top section of the oesphagus is ____ muscle under ____ control
A) Skeletal muscle
B) Voluntary control
Lower section of the oesphagus is ____ muscle under ____ control
A) Smooth muscle
B) involuntary control
What is the angle of His
This is the angle in which the oesphagus becomes continous with the stomach.
Important as it anatomical preventions acid reflux
What tests could we do to examine oesophageal function?
Barium swallow - patient swallows barrium and X-ray can view the pathway for the barium into the stomach
High resolution manometry - Catheter inserted through the nose and allows recording of the pressures within the oesphagus and proximal stomach.
What is this test called
High resolution manometry
Why is hiatus hernia’s associated with gastro-oesphageal reflux disease?
In the HH, part of the stomach protrudes through the diagraphm into the thorax region.
The parietal cells in this protuding part of the stomach does not have food present to buffer the acid they produce.
Similiarly, no lower oesphageal present or angle of His to prevent the reflux
What are the possible treatments for gastro-oesphageal reflux disease
Lifestyle advice
- Reduce tea, coffee and alcohol
- Weight loss
- Avoid smoking
- Smaller, lighter meals
- Avoid heavy meals before bed time
- Stay upright after meals rather than lying flat
Acid neutralising medication when required:
- Gaviscon
- Rennie
Proton pump inhibitors (reduce acid secretion in the stomach)
- Omeprazole
- Lansoprazole
Ranitidine
- This is an alternative to PPIs
- H2 receptor antagonist (antihistamine)
- Reduces stomach acid
How does Proton pump inhibitor work?
Proton pump inhibitors act by irreversibly blocking the H+/K+ ATPase or the gastric proton pump of the gastric parietal cells.
The proton pump is the terminal stage in gastric acid secretion, being directly responsible for secreting H+ ions into the gastric lumen
Less H+ are secreted into the lumen of the stomach. Less gastric acid formed
Name some of the surgical treatment options for gastro-oesphageal reflux disease
Surgery is called laparoscopic fundoplication.
This involves tying the fundus of the stomach around the lower oesophagus to narrow the lower oesophageal sphincter.
