August 10, 2015 - Gastric Secretion

Question 1

Mucus Cells

Answer 1

Secrete mucus and pepsinogen II.

Question 2

Parietal Cells

Answer 2

Secrete HCl and intrinsic factor.

(Intrinsic factor is needed for the absorption of vitamin B₁₂ later in the small intestine)

Question 3

Chief Cells

Answer 3

Secrete pepsinogen I

Question 4

D Cells

Answer 4

Secrete somatostatin

(Somatostatin acts directly on the acid-producing parietal cells thus antagonizing the stimulatory effect of histamine to reduce acid secretion.)

Question 5

G Cells

Answer 5

Secrete gastrin

(Gastrin is a peptide hormone that stimulates the secretion of HCl by the parietal cells of the stomach)

Question 6

Mast Cells

Answer 6

Secrete histamine

Question 7

Things that will cause an increase in acid secretion

Answer 7

• Histamine
• Acetylcholine
• Gastrin

Question 8

Things that will cause a decrease in acid secretion

Answer 8

• Prostaglandins
• Somatostatin

Question 9

Zollinger-Ellison Syndrome

Answer 9

Is caused by a non-beta islet cell (islet of Langerhands) gastrin-secreting tumor of the pancrease that stimulates the acid-secreting cells of the stomach to maximal activity, with consequent gastrointestinal mucosal ulceration. The high acidity causes multiple ulcers to form in the stomach and duodenum.

The primary tumor is usually located in the pancreas, duodenum, or abdominal lymph nodes.

TREATMENT is done by administering proton pump inhibitors and tumors may need to be surgically removed or treated with chemotherapy.

Question 10

Peptic Ulcer Disease Symptoms

Answer 10

Abdominal pain that may be described as…

• Burning, gnawing
• Stabbing through the back
• Worsen with food (often gastric ulcers)
• Improve with eating (often duodenal ulcer)

Will also typically include…

• Bloating or cramping
• Nausea, vomiting (blood or coffee-grounds)
• Decreased appetite
• Weight loss
• Bloody or tarry black stolls
• Fatigue and malaise

Question 11

Agressive Factors for Ulcers

Answer 11

• Acid, pepsin
• NSAIDs
• Alcohol
• Bile
• H. pylori

Question 12

Helicobacter pylori and the World

Answer 12

In North America, adults are typically 20-30% positive

In developing countries, adults are 80-90% positive

Acquisition generally occurs in childhood through the drinking of contaminated water, or through oral-oral or oral-fecal routes.