PHY 503: EXAM 3 PRACTICE TEST QUESTIONS WITH
ACCURATE SOLUTIONS
1) The gastric phase of gastric secretion accounts for about 60% of the acid response
to a meal. Which substance can virtually eliminate the secretion of acid during the
gastric phase?
A) antacids
B) antigastrin antibodies
C) atropine
D) histamine H2 blocker
E) proton pump inhibitor -- Correct Answer ✔✔ E) proton pump inhibitor
A proton pump inhibitor such as omeprazole inhibits all acid secretion by directly
inhibiting H+/K+/ATPase. The parietal cell has receptors for secretagogues such
as gastrin, ACh, and histamine. Therefore antigastrin antibodies, atropine, and
histamine H2 blockers can reduce secretion of acid, but none can completely
eliminate acid secretion. Antacids neutralize gastric acid once it has entered the
stomach, but they cannot inhibit acid secretion from parietal cells.
2) Gastric acid is secreted when a meal is consumed. Which factors have a direct
action on the parietal cell to stimulate acid secretion?
A) gastrin
B) somatostatin
C) ACh
D) histamine -- Correct Answer ✔✔ A, C, and D
, Gastrin, ACh, and histamine can directly stimulate parietal cells to secrete acid.
These three secretagogues also have a multiplicative effect on acid secretion such
that the inhibition of one secretagogue reduces the effectiveness of the remaining
two. ACh also has an indirect effect to increase acid secretion by stimulating
gastrin secretion from G cells. Somatostatin inhibits acid secretion.
3) Which of the following can inhibit gastric acid secretion?
A) somatostatin
B) secretin
C) GLIP
D) enterogastrones
E) nervous reflexes
F) all of the above -- Correct Answer ✔✔ F) all of the above
Gastric acid stimulates the release of SST, which has a direct effect on the
parietal cell to inhibit acid secretion, as well as an indirect effect mediated by
suppression of gastrin secretion. Secretin and GLIP inhibit acid secretion though
direct action on parietal cells, as well as indirectly through suppression of gastrin
secretion. Enterogastrones are unidentified substances released from the
duodenum and jejunum that directly inhibit acid secretion. When acid or
hypertonic solutions enter the duodenum, an neurally mediated decrease in
gastric acid secretion follows.
4) An 82 y/o woman with upper abdominal pain and blood in the stool has been taking
NSAIDs for arthritis. Endoscopy reveals patchy gastritis throughout the stomach.
Biopsies were negative for H. pylori. Pentagastrin administered intravenously would
lead to a less than normal increase in which of the following?
A) duodenal mucosal growth
B) gastric acid secretion
C) gastrin secretion
D) pancreatic enzyme secretion
, E) pancreatic growth -- Correct Answer ✔✔ B) gastric acid secretion
NSAID use may result in NSAID-associated gastritis or peptic ulcer. Chronic
gastritis by definition is a histopathological entity characterized by chronic
inflammation of the stomach mucosa. When inflammation affects the gastric
corpus, parietal cells are inhibited, leading to reduced acid secretion.
Administration of pentagastrin should produce a less than expected increase in
gastric acid secretion. Although gastrin and pentagastrin can both stimulate
growth of the duodenal mucosa, it should be clear that IV pentagastrin would not
cause substantial growth in the context of a clinical test. In any case, chronic
administration of pentagastrin would not lead to less than expected growth of
the duodenal mucosa. Pentagastrin is not expected to increase gastrin secretion,
pancreatic enzyme secretion, or pancreatic growth.
5) Which substances have a physiological role in stimulating release of hormones or
stimulating neuronal reflexes, which in turn can inhibit gastric acid secretion?
A) acid
B) fatty acids
C) hyperosmotic solutions
D) isotonic solutions -- Correct Answer ✔✔ A, B, and C
The presence of acid, fatty acids, and hyperosmotic solutions in the duodenum
and jejunum leads to suppression of acid secretion. Acid stimulates the secretion
of secretin from the SI, which in turn inhibits acid secretion from parietal cells.
Acidification of the antrum and oxyntic gland area of the stomach stimulates SST
release, which in turn inhibits gastric acid secretion by a direct action on the
parietal cells, and an indirect action mediated by suppression of gastrin secretion.
The presence of fatty acids in the SI stimulates the release of GLIP, which inhibits
acid secretion both directly (parietal cell inhibition), and indirectly (by decreasing
gastrin secretion). Hyperosmotic solutions in the SI cause the release of
unidentified enterogastrones, which directly inhibit acid secretion from parietal
cells. Isotonic solutons have no effect on acid secretion.
ACCURATE SOLUTIONS
1) The gastric phase of gastric secretion accounts for about 60% of the acid response
to a meal. Which substance can virtually eliminate the secretion of acid during the
gastric phase?
A) antacids
B) antigastrin antibodies
C) atropine
D) histamine H2 blocker
E) proton pump inhibitor -- Correct Answer ✔✔ E) proton pump inhibitor
A proton pump inhibitor such as omeprazole inhibits all acid secretion by directly
inhibiting H+/K+/ATPase. The parietal cell has receptors for secretagogues such
as gastrin, ACh, and histamine. Therefore antigastrin antibodies, atropine, and
histamine H2 blockers can reduce secretion of acid, but none can completely
eliminate acid secretion. Antacids neutralize gastric acid once it has entered the
stomach, but they cannot inhibit acid secretion from parietal cells.
2) Gastric acid is secreted when a meal is consumed. Which factors have a direct
action on the parietal cell to stimulate acid secretion?
A) gastrin
B) somatostatin
C) ACh
D) histamine -- Correct Answer ✔✔ A, C, and D
, Gastrin, ACh, and histamine can directly stimulate parietal cells to secrete acid.
These three secretagogues also have a multiplicative effect on acid secretion such
that the inhibition of one secretagogue reduces the effectiveness of the remaining
two. ACh also has an indirect effect to increase acid secretion by stimulating
gastrin secretion from G cells. Somatostatin inhibits acid secretion.
3) Which of the following can inhibit gastric acid secretion?
A) somatostatin
B) secretin
C) GLIP
D) enterogastrones
E) nervous reflexes
F) all of the above -- Correct Answer ✔✔ F) all of the above
Gastric acid stimulates the release of SST, which has a direct effect on the
parietal cell to inhibit acid secretion, as well as an indirect effect mediated by
suppression of gastrin secretion. Secretin and GLIP inhibit acid secretion though
direct action on parietal cells, as well as indirectly through suppression of gastrin
secretion. Enterogastrones are unidentified substances released from the
duodenum and jejunum that directly inhibit acid secretion. When acid or
hypertonic solutions enter the duodenum, an neurally mediated decrease in
gastric acid secretion follows.
4) An 82 y/o woman with upper abdominal pain and blood in the stool has been taking
NSAIDs for arthritis. Endoscopy reveals patchy gastritis throughout the stomach.
Biopsies were negative for H. pylori. Pentagastrin administered intravenously would
lead to a less than normal increase in which of the following?
A) duodenal mucosal growth
B) gastric acid secretion
C) gastrin secretion
D) pancreatic enzyme secretion
, E) pancreatic growth -- Correct Answer ✔✔ B) gastric acid secretion
NSAID use may result in NSAID-associated gastritis or peptic ulcer. Chronic
gastritis by definition is a histopathological entity characterized by chronic
inflammation of the stomach mucosa. When inflammation affects the gastric
corpus, parietal cells are inhibited, leading to reduced acid secretion.
Administration of pentagastrin should produce a less than expected increase in
gastric acid secretion. Although gastrin and pentagastrin can both stimulate
growth of the duodenal mucosa, it should be clear that IV pentagastrin would not
cause substantial growth in the context of a clinical test. In any case, chronic
administration of pentagastrin would not lead to less than expected growth of
the duodenal mucosa. Pentagastrin is not expected to increase gastrin secretion,
pancreatic enzyme secretion, or pancreatic growth.
5) Which substances have a physiological role in stimulating release of hormones or
stimulating neuronal reflexes, which in turn can inhibit gastric acid secretion?
A) acid
B) fatty acids
C) hyperosmotic solutions
D) isotonic solutions -- Correct Answer ✔✔ A, B, and C
The presence of acid, fatty acids, and hyperosmotic solutions in the duodenum
and jejunum leads to suppression of acid secretion. Acid stimulates the secretion
of secretin from the SI, which in turn inhibits acid secretion from parietal cells.
Acidification of the antrum and oxyntic gland area of the stomach stimulates SST
release, which in turn inhibits gastric acid secretion by a direct action on the
parietal cells, and an indirect action mediated by suppression of gastrin secretion.
The presence of fatty acids in the SI stimulates the release of GLIP, which inhibits
acid secretion both directly (parietal cell inhibition), and indirectly (by decreasing
gastrin secretion). Hyperosmotic solutions in the SI cause the release of
unidentified enterogastrones, which directly inhibit acid secretion from parietal
cells. Isotonic solutons have no effect on acid secretion.
