Gastric disease

Question 1

What is the main gastric cancer?

Answer 1

adenocarcinoma

Question 2

What is gastric cancer caused by?

Answer 2

H. pylori infection causing gastritis and intestinal metaplasia then leading to dysplasia

Question 3

What are the symptoms of gastric cancer?

Answer 3

weight loss, lethargy, abdominal pain, early satiety, nausea and vomiting, haematemesis or melaena

Question 4

What is the treatment for gastric cancer?

Answer 4

Surgery or chemo-radiotherapy to first shirnk then surgery

Question 5

What does nausea involve?

Answer 5

the feeling of needing to be sick

• pallor
• sweating
• excessive salivation
• relaxation of the stomach and oesophagus
• reverse peristalsis

Question 6

What is retching?

Answer 6

• rhythmic reverse peristalsis of the stomach and oesophagus (cardiac into thorax)
• contraction of anterior abdominal muscles
• reverse peristalsis
• pallor

Question 7

What are the key events in vomiting?

Answer 7

• Suspension of intestinal slow wave activity
• Retrograde contractions from ileum to stomach
• Suspension of breathing
• Relaxation of LOS contraction of diaphragm and abdominal muscles compresses the stomach
• Ejection of gastric contents through open UOS
• Repeat

Question 8

What is vomiting coordinated by?

Answer 8

vomiting centre in the medulla oblongata

Question 9

What stimulates vomiting?

Answer 9

• Toxic materials in gut
• Stimulates enterochromaffin cells in the mucosa
• Depolarisation of sensory afferent terminals in mucosa
• Action potential discharge in vagal afferents to brainstem
• Coordination of vomiting by the vomiting centre

Question 10

What is the main thing that is stimulated to cause vomiting?

Answer 10

CTZ of the medulla

Question 11

What are some of the severe causes of vomiting?

Answer 11

• dehydration
• loss of gastric protons and chloride
• hypokalaemia

Question 12

What are the three main centres in the brain that are involved in vomiting?

Answer 12

Chemoreceptor trigger zone
Nucleus tractussoltarius
Vomiting Centre

Question 13

What are the motor outputs that coordinate vomiting?

Answer 13

• somatic motor neurones outflow is to diaphragm and anterior abdominal muscle
• vagal efferent outflow is to stomach, oesophagus and small intestine
• autonomic/ somatic efferent outflow to the heart, salivary glands, skin and sphincters at bladder and anus

Question 14

What is dyspepsia?

Answer 14

Dyspepsia is classed as epigastric pain, postprandial fullness and early satiety

Question 15

What are the factors that can make dyspepsia more likely?

Answer 15

H.pylori

NSAID use

Question 16

What can dyspepsia be caused by?

Answer 16

• Organic (peptic ulcer disease, drugs or gastric cancer)

- Functional (no evidence of structural disease even on endoscopy)

Question 17

What are the symptoms of dyspepsia?

Answer 17

• uncomplicated = epigastric pain

- complicated = mass, vomiting or peritonism

Question 18

What features does H.pylori have that helps it colonise the gastric mucosa?

Answer 18

• flagella to burrow into mucus lining where the pH is more neutral
• adhesins on surface so it adheres to the gastric mucosa
• production or urease to neutralise stomach acid