Topic 4 part 1.a&b - disorders of small & large intestine

Question 1

GIT condition: Hiatal Hernia

Answer 1

occurs when part of the stomach protrudes through the diaphram. Gastro-oesophageal reflux occurs as a result.

Question 2

GIT condition: Dysphagia

Answer 2

difficulty in swallowing (leading to pain in swallowing). Causes: narrowing of oesophagus, decreased saliva

Question 3

GIT condition: Achalasia

Answer 3

is failure of Lower Oesophageal Sphincter to relax (giving a ‘birds beak’ appearance.

Question 4

GIT condition: Oesophageal Diverticulum

Answer 4

outpouching of oesophageal wall due to muscularis layer weakness.

Question 5

GIT condition: Enterocolitis

Answer 5

inflammation of both the small & large intestine: from Viral, Bacterial or Protozoan infection.

Question 6

GIT condition: Appendicitis

Answer 6

Appendix of the GIT becomes inflammed, swolllen & gangrenous

Question 7

GIT condition: Peritomitis

Answer 7

inflammation of the peritoneum. Due to: perforated peptic ulcer, ruptured appendix, perforated diverticulum, gangrenous bowel. Leading cause of death after abdominal surgery.

Question 8

GIT condition: Irritable Bowel Syndrome

Answer 8

functional GIT disorder not explained by structural or biochemical abnormalities.
3 subgroups: 
- constipation
- diarrhea
- combo of both

Question 9

Define: Haematemesis

Answer 9

blood in vomitus.

• Bright red = haemorrhage above the stomach.
• Coffee grounds in appearence = haemorrhage in stomach w’ partial digestion of blood.

Question 10

Define: Occult Blood

Answer 10

haemorrhage in intestines w’ blood ‘occult’ or hidden in stools.

Question 11

Define: Melana

Answer 11

haemorrhage into intestines w’ large volume of blood = black tarry & smelly faeces.

Question 12

Define: Haematochezia

Answer 12

blood in faeces from rectum (haemorrhoids)

Question 13

Describe the neuronal coordination of vomiting

Answer 13

2 ways:
1. neurons in the CTZ (Chemoreceptor Trigger Zone) responds to blood born emetics, i.e. toxins from bacteria, drugs.
2. Sensory input from sense centres / area of brain i.e. sight, smell.
Neuro-transmitters = Acetylcholine (Ach), Serotonin (5-HT), Histamine & Dopamine (DA).
These 2 ways activate the emetic centre = initiates the vomiting process.

Question 14

Treatment of Nausea / Vomiting

Answer 14

Antagonist of the neuro-transmiter receptors.

• Anticholinergics: used for motion induced nausea.
• 5-HT(3) receptor antagonist: inhibit CTZ.
• H1 (histamine) receptor antagonist:
• Dopamine antagonist: inhibit CTZ.

Question 15

Pathogenesis of Gastro-oesophageal reflux

Answer 15

GERD/GORD is a clinical syndrome involving the reflux of gastric contents into the esophagus due to weak / incompetent LES.

Question 16

Pharmacological treatments of Gastro-oesophageal reflux

Answer 16

• Antacids: neutralise gastric acid & raise gastric pH.
• Proton Pump inhibitors: inhibits H+/K+ ATPase (proton pump) to reduce gastric acid secretion.
• H2 receptor antagonists: competively block histamine from stimulating parietal cells.