1. Exposure to which substance protects the mucosal barrier of the stomach?

a. Prostaglandins

b. Helicobacter pylori

c. Aspirin

d. Regurgitated bile

Prostaglandins. Prostaglandins and enterogastrones,such as gastric inhibitory

peptide, somatostatin, and secretin, inhibit acid secretion.

2. Glucose transport enhances the absorption of which electrolyte?

a. Sodium

b. Potassium

c. Phosphate

d. Chloride

Sodium. Sodium passes through the tight junctions and is actively transported

across cell membranes. Sodium and glucose share a common active transport

carrier (sodium-glucose ligand transporter 1 [SGLT1]).

3. What isthe cause of gastroesophageal reflux disease?

a. Excessive production of hydrochloric acid

b. Zone of low pressure of the lower esophageal sphincter

c. Presence of Helicobacter pylori in the esophagus

d. Reverse muscular peristalsis of the esophagus

Zone of low pressure of the lower esophageal sphincter. Normally, the resting

tone of the lower esophageal sphincter maintains a zone of high pressure that

prevents gastroesophageal reflux. In individuals who develop reflux esophagitis,

this pressure tends to be lower than normal from either transient relaxation or a

weakness of the sphincter.

4. By what mechanism doesintussusception cause an intestinal obstruction?

a. Telescoping of part of the intestine into anothersection of intestine,

usually causing strangulation of the blood supply

b. Twisting the intestine on its mesenteric pedicle, causing occlusion of the

blood supply

c. Loss of peristaltic motor activity in the intestine, causing an adynamic ileus

d. Forming fibrin and scar tissue that attach to the intestinal omentum,

causing obstruction

A. Intussusception is the telescoping of part of the intestine into another section

of intestine, usually causing strangulation of the blood supply.

5. What is the most immediate result of a small intestinal obstruction?

a. Vomiting

b. Electrolyte imbalances