Pathophysiology: Chapter 42: Alterations of Digestive Function Flashcards
Where in the brain is the vomiting center located?
a. Hypothalamus c. Pons
b. Medulla oblongata d. Midbrain
ANS: B
The vomiting center of the brain lies in the medulla oblongata. The other locations listed
are not related to vomiting.
Antiemetic agents, such as domperidone and haloperidol, are antagonists for which receptors? a. 5-Hydroxytryptamine (5-HT) serotonin b. Histamine-2 c. Acetylcholine d. Dopamine
ANS: D
Metoclopramide, domperidone, and haloperidol are dopamine antagonists, making them
effective antiemetic agents. This selection is the only option that identifies a receptor that
is involved in the process of vomiting.
What type of vomiting is caused by the direct stimulation of the vomiting center by
neurologic lesions involving the brainstem?
a. Retch c. Duodenal
b. Periodic d. Projectile
ANS: D
Of the available options, only projectile vomiting is caused by the direct stimulation of the
vomiting center by neurologic lesions, such as increased intracranial pressure, tumors, or
aneurysms involving the brainstem.
Considering the normal frequency of bowel evacuation, how infrequently can evacuation
occur and still be considered within normal range?
a. Once a day
b. Once every 2 days
c. Once a week
d. Once every 2 weeks
ANS: C
Normal bowel habits range from two or three evacuations per day to one per week.
How many stools per day are considered the upper limits of normal?
a. Two c. Five
b. Three d. Seven
l.
ANS: B
More than three stools per day is considered abnorma
The adult intestine processes approximately how many liters of luminal content per day?
a. 3 c. 9
b. 6 d. 12
ANS: C
The adult intestine processes approximately 9 L of luminal content per day. Of this
amount, 2 L is ingested and the remaining 7 L consists of intestinal secretions.
A person who has cholera would be expected to have which type of diarrhea?
a. Osmotic c. Small volume
b. Secretory d. Motility
ANS: B
Primary causes of secretory diarrhea are bacterial enterotoxins, particularly those released
by cholera or strains of Escherichia coli, and neoplasms, such as gastrinoma or thyroid
carcinoma. None of the other options are associated with secretory diarrhea.
What type of diarrhea is a result of lactase deficiency?
a. Motility c. Secretory
b. Osmotic d. Small-volume
ANS: B
Malabsorption related to lactase deficiency, pancreatic enzyme or bile salt deficiency,
small intestine bacterial overgrowth, and celiac disease cause osmotic diarrhea. None of
the other options are associated with lactase deficiencies.
Which statement is false concerning how abdominal pain is produced?
a. Chemical mediators, such as histamine, bradykinin, and serotonin, produce
abdominal pain.
b. Edema and vascular congestion produce abdominal pain by stretching.
c. Ischemia, caused by distention of bowel obstruction or mesenteric vessel
thrombosis, produces abdominal pain.
d. Low concentrations of anaerobes, such as Streptococci, Lactobacilli,
Staphylococci, Enterobacteria, and Bacteroides, produce abdominal pain.
ANS: D
Low concentrations of anaerobes are not typically a cause of abdominal pain.
How can abdominal pain that is visceral in nature best be described?
a. Abdominal pain that is visceral in nature is diffused, vague, poorly localized, and
dull.
b. It travels from a specific organ to the spinal cord.
c. The pain lateralizes from only one side of the nervous system.
d. Abdominal pain is associated with the peristalsis of the gastrointestinal tract.
ANS: A
Pain is usually felt near the midline in the epigastrium (upper midabdomen), midabdomen,
or lower abdomen. The pain is poorly localized, is dull rather than sharp, and is difficult to
describe. None of the other options accurately describe this type of pain.
What is the 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
.
ANS: B
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. This selection is the only option that accurately describes the
cause of gastroesophageal reflux disease
What term is used to identify frank bleeding of the rectum?
a. Melena c. Occult bleeding
b. Hematochezia d. Hematemesis
ANS: B
Hematochezia is the only available option that is associated with frank bright red or
burgundy blood from the rectum.
What is the cause of functional dysphagia?
a. Intrinsic mechanical obstruction
b. Extrinsic mechanical obstruction
c. Tumor
d. Neural or muscular disorders
ANS: D
Neural or muscular disorders that interfere with voluntary swallowing or peristalsis cause
functional dysphagia. This selection is the only option that accurately identifies a cause of
functional dysphagia.
What is the cause of reflux esophagitis?
a. Immune response to gastroesophageal reflux
b. Delayed gastric emptying
c. Congenital anomaly
d. Secretory response to gastroesophageal reflux
ANS: B
Delayed gastric emptying contributes to reflux esophagitis by (1) lengthening the period
during which reflux is possible and (2) increasing the acid content of chyme. None of the
other options are accurate descriptions of the cause of reflux esophagitis.
By what mechanism does intussusception cause an intestinal obstruction?
a. Telescoping of part of the intestine into another section 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
ANS: A
Intussusception is the telescoping of part of the intestine into another section of intestine,
usually causing strangulation of the blood supply. This selection is the only option that
accurately describes how intussusception causes an intestinal obstruction.
What is the most immediate result of a small intestinal obstruction?
a. Vomiting c. Electrolyte imbalances
b. Dehydration d. Distention
ANS: D
Distention begins almost immediately, as gases and fluids accumulate proximal to the
obstruction. Within 24 hours, up to 8 L of fluid and electrolytes enters the lumen in the
form of saliva, gastric juice, bile, pancreatic juice, and intestinal secretions. Copious
vomiting or sequestration of fluids in the intestinal lumen prevents their reabsorption and
produces severe fluid and electrolyte disturbances.
An intestinal obstruction at the pylorus or high in the small intestine causes metabolic
alkalosis by causing which outcome?
a. Gain of bicarbonate from pancreatic secretions that cannot be absorbed
b. Excessive loss of hydrogen ions normally absorbed from gastric juices
c. Excessive loss of potassium, promoting atony of the intestinal wall
d. Loss of bile acid secretions that cannot be absorbed
ANS: B
If the obstruction is at the pylorus or high in the small intestine, then metabolic alkalosis
initially develops as a result of excessive loss of hydrogen ions that normally would be
reabsorbed from the gastric juices. This selection is the only option that accurately
describes the cause of metabolic alkalosis in this situation.
What are the cardinal symptoms of small intestinal obstruction?
a. Constant, dull pain in the lower abdomen relieved by defecation
b. Acute, intermittent pain 30 minutes to 2 hours after eating
c. Colicky pain caused by distention, followed by vomiting
d. Excruciating pain in the hypogastric area caused by ischemia
ANS: C
Of the options available, only colicky pain caused by distention followed by vomiting are
considered the cardinal symptoms of a small intestinal obstruction.
What is a cause of chronic antral gastritis?
a. Helicobacter pylori bacteria
b. Development of autoantibodies to gastric H+/K+ ATPase
c. Pernicious anemia
d. Reflux of bile and alkaline pancreatic secretions
ANS: A
Chronic antral gastritis generally involves only the antrum and is more common than
fundal gastritis. It is caused by H. pylori bacteria or the chronic use of alcohol, tobacco,
and nonsteroidal antiinflammatory drugs. None of the other options are associated with the
cause of chronic antral gastritis.
What is the primary cause of peptic ulcers?
a. Hypersecretion of gastric acid
b. Hyposecretion of pepsin
c. Helicobacter pylori
d. Escherichia coli
ANS: C
Infection with H. pylori is a primary cause of peptic ulcers.
ANS: C
Infection with H. pylori is a primary cause of peptic ulcers.
A peptic ulcer may occur in all of the following areas except the:
a. Stomach c. Jejunum
b. Duodenum d. Esophagus
ANS: C
A peptic ulcer is a break, or ulceration, in the protective mucosal lining of the lower
esophagus, stomach, or duodenum. This type of ulcer is not associated with the jejunum.
Which statement is false regarding the contributing factors of duodenal ulcers?
a. Bleeding from duodenal ulcers causes hematemesis or melena.
b. Gastric emptying is slowed, causing greater exposure of the mucosa to acid.
c. The characteristic pain begins 30 minutes to 2 hours after eating when the stomach
is empty.
d. Duodenal ulcers occur with greater frequency than other types of peptic ulcers.
ANS: B
Duodenal ulcers can be associated with altered mucosal defenses, rapid gastric emptying,
elevated serum gastrin levels, or acid production stimulated by smoking. The other options
provide correct information regarding duodenal ulcers
After a partial gastrectomy or pyloroplasty, clinical manifestations that include increased
pulse, hypotension, weakness, pallor, sweating, and dizziness are the results of which
mechanism?
a. Anaphylactic reaction in which chemical mediators, such as histamine,
prostaglandins, and leukotrienes, relax vascular smooth muscles, causing shock
b. Postoperative hemorrhage during which a large volume of blood is lost, causing
hypotension with compensatory tachycardia
c. Concentrated bolus that moves from the stomach into the small intestine, causing
hyperglycemia and resulting in polyuria and eventually hypovolemic shock
d. Rapid gastric emptying and the creation of a high osmotic gradient in the small
intestine, causing a sudden shift of fluid from the blood vessels to the intestinal
lumen
ANS: D
Dumping syndrome occurs with varying severity in 5% to 10% of individuals who have
undergone partial gastrectomy or pyloroplasty. Rapid gastric emptying and the creation of
a high osmotic gradient in the small intestine cause a sudden shift of fluid from the
vascular compartment to the intestinal lumen. Plasma volume decreases, causing
vasomotor responses, such as increased pulse rate, hypotension, weakness, pallor,
sweating, and dizziness. Rapid distention of the intestine produces a feeling of epigastric
fullness, cramping, nausea, vomiting, and diarrhea. This selection is the only option that
accurately identifies the mechanism responsible for the described situation.
Which statement is consistent with dumping syndrome?
a. Dumping syndrome usually responds well to dietary management.
b. It occurs 1 to 2 hours after eating.
c. Constipation is often a result of the dumping syndrome.
d. It can result in alkaline reflux gastritis.
ANS: A
Most individuals with the dumping syndrome respond well to dietary management. None
of the other options is associated with the dumping syndrome.
