GI Motility

Question 1

Gastroparesis

Answer 1

Slow emptying of the stomach/ paralysis of the stomach 
-20% Type 1 diabetic patients (some type 2) 
Cause: Damage to the Vagus N. 
- Idopathic 
- High blood glucose (diabetic gastroparesis)
Symptoms: 
- Nausea
- Vomiting 
- Early feeling of fullness when eating
- Weight Loss
- Abdominal Bloating 
- Abdominal Discomfort 

• DAMAGE TO THE VAGUS N IS ASSOCIATED WITH HIGH LEVELS OF GLUCOSE

Question 2

Pernicious Anemia

What is it?
What causes it? (2)

Answer 2

Stomach does not produce enough IF
loss of Vitamin B12

Common Causes:
- Atrophic Gastritis - chronic inflammation of the stomach mucosa that leads to the loss of parietal cells

• Autoimmune Metaplastic Atrophic Gastritis - immune system attacks IF protein or gastric parietal cells

Question 3

Zollinger-Ellison Syndrome

Answer 3

• The highest rates of H+ secretion
• A tumor (usually In the pancreas) secretes large quantities of gastrin
• Two effects of high gastrin:
  1. Increased H+ secretion by parietal cells
  2. Increased parietal cell mass
• The delivery of excessive amounts of H+ to the duodenum overwhelms the buffering capacity of the duodenum. - Overwhelms the buffering capacity of HCO3- in pancreatic juices and erodes the mucosa and produces an ulcer
• Can cause STEATORRHEA - low duodenal pH will inactivate the pancreatic lipases necessary for fat digestion

Secretin stimulation test

Question 4

Peptic Ulcers

Answer 4

• Caused by H. pylori infection and the use of NSAIDs (Asprin)
• Ulcerative lesion of gastric or duodenal mucosa
• Cause by the erosive and digestive action of H+ and pepsin on the mucosa which is normally protected by the layer of mucus and HCO3-
• Could be the result of:
• Loss of protective mucosal barrier
• Excessive H+ and pepsin secretions
• Combination of the two

Two types: gastric ulcers and duodenal ulcers

Question 5

Gastric Ulcers

Answer 5

Found in the lining of the stomach - main problem is the defective gastric mucosa barrier, rather than having an increase in acid production.

Net H+ is LOWER because some of the secreted H+ leaks into the damaged mucosa –> secretion of gastrin is INCREASED because of the reduced net H+

Major causative agent is H. pylori

Question 6

Duodenal Ulcers

Answer 6

• Formed on the lining of the duodenum
• More common than gastric ulcers
• Usually do not become malignant
• H+ secretion is HIGHER than normal –> if excess H+ is delivered to the duodenum then it will overwhelm the buffering capacity of HCO3- in pancreatic juice
  Acting with pepsin, this excess H+ will digest and damage the duodenal mucosa
• Caused by H. pylori infection