Lab 1: Presentation 2

Question 1

Define gastro-oesphageal reflux disease

Answer 1

Defined as the gastric acid from the stomach refluxes through the lower oesophageal sphincter and irritates the lining of the oesophagus.

Question 2

Why is the oesphageal more sensitive to gastric acid than the stomach is?

Answer 2

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.

Question 3

What are the most common symptoms for gastro-oesphageal reflux disease

Answer 3

• Heartburn
• Acid regurgitation
• Retrosternal or epigastric pain
• Bloating
• Nocturnal cough
• Hoarse voice

Question 4

The oesphageal is a 25cm muscular tube that connects from the ___ to the ____

Answer 4

A) Pharynx

B) Stomach

Question 5

What are the layers that make up the wall of the oesphagus

Answer 5

1. Mucosa (innermost)
2. Submucosa
3. Muscular external
   
   1. Circular
   2. Longitudinal
4. Adventitia/Serosa

Question 6

Where does the pharynx become continous with the oesphagus

Answer 6

At the level of C6 vertebrae

Question 7

The oesphagus passes through the ____ of the diaphragm

Answer 7

Right crus

Question 8

What anatomical and physiological arrangements protect against gastro-oesphageal reflux?

Answer 8

• 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

Question 9

What is a hiatus hernia?

Answer 9

This is when the upper part of the stomach protrudes through the diaphragm into the thoracic cavity

Question 10

Which cells (between chief and parietal cells) lies more superior in the gastric gland

Answer 10

Parietal cells lies closer to the enterance of the gastric gland in comparison to the Chief cells

Question 11

Which cell type in the gastric mucosa secretes intrinsic factor

Answer 11

Parietal cell

Question 12

Why is intrinsic factor important?

Answer 12

It binds to vitamin B12 and allows it to be absorbed from the ileum

Question 13

What type of epithelium lines the oesphagus?

Answer 13

Stratified squamous non-keratinised epithelium

Question 14

What is “metaplasia”

Answer 14

The change in the cells from one form to another

Question 15

What is the mechanism of action for omeprazole

Answer 15

Proton pump inhibitor

Question 16

What is the mechanims of action for Cimetidine

Answer 16

H2 receptor antagonist

Question 17

Name drugs that can be used to manage a patient with gastro-oesphageal reflux disease

Answer 17

• Omeprazole
• Cimetidine
• Gavison
• Aluminium hydroxide

Question 18

What is the mechanism of action for Alginate Antacid?

Answer 18

e.g. peptac/gavison

Forms a “raft” that floats on the surface of stomach contents to reduce reflux

Question 19

What is the mechanism of action ofr aluminium hydroxide?

Answer 19

Acts by binding to free H+ ions

Question 20

The oesphagus is located ___ to the trachea

Answer 20

Posterior

Question 21

The muscularis externa of the oesphagus contains two types of muscle fibres. Name them?

Answer 21

Skeletal and smooth muscle fibres

Question 22

Name the two types of hiatus hernia

Answer 22

Sliding and rolling

Question 23

Describe the difference between a sliding hiatus hernia and a rolling hiatus hernia

Answer 23

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

Question 24

Name some of the red flag symptoms of a GI investigation

Answer 24

1. Unexplained weight loss
2. Dysphagia (swallowing difficulties)
3. Persistent vomiting
4. GI blood loss
5. Upper abdominal mass

Question 25

Describe the mechanism of oesphageal phase of swallowing

Answer 25

* 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

Question 26

What are possible causes for dysphagia?

Answer 26

**Intrinsic causes**: foreign body, tumours etc **Extrinsic** **causes**: pressure from lymph nodes **Motility** **disorders**: achalasia, oesphageal spasm **Neuromuscular** **disorders**: cerebrovascular diseaes

Question 27

What does dysphagia mean

Answer 27

Swallowing difficulties

Question 28

Describe achalasia

Answer 28

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

Question 29

Describe Barrett's oesphagus

Answer 29

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.

Question 30

Describe oesphagitis

Answer 30

Inflammation of the squamous mucosa secondary to acid damage. Can cuse strictures (narrowing of the oesphagus)

Question 31

Barretts oesophagus is a risk factor for the development into?

Answer 31

Adenocarcinoma (maligant tumour of the oesphagus- high mortality rate)

Question 32

Oesophagitis is a risk factor for the development into?

Answer 32

Barrett's oesphagus (metaphasic changes in the epithelium) if chronic exposure of the oesphagus to gastric acid

Question 33

What are the complications of acid reflux?

Answer 33

* **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

Question 34

This image is an example of which condition of the oesphagus

Answer 34

Barrett's oesphagus

Question 35

Top section of the oesphagus is ____ muscle under ____ control

Answer 35

A) Skeletal muscle B) Voluntary control

Question 36

Lower section of the oesphagus is ____ muscle under ____ control

Answer 36

A) Smooth muscle B) involuntary control

Question 37

What is the angle of His

Answer 37

This is the angle in which the oesphagus becomes continous with the stomach. Important as it anatomical preventions acid reflux

Question 38

What tests could we do to examine oesophageal function?

Answer 38

**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.

Question 39

What is this test called

Answer 39

High resolution manometry

Question 40

Why is hiatus hernia's associated with gastro-oesphageal reflux disease?

Answer 40

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

Question 41

What are the possible treatments for gastro-oesphageal reflux disease

Answer 41

**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

Question 42

How does Proton pump inhibitor work?

Answer 42

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

Question 43

Name some of the surgical treatment options for gastro-oesphageal reflux disease

Answer 43

Surgery is called **laparoscopic** **fundoplication**. This involves tying the fundus of the stomach around the lower oesophagus to narrow the lower oesophageal sphincter.