17. A newborn boy does not pass meconium in the first 24 hours. His abdomen is distended,
and he begins vomiting. Various other tests lead to a diagnosis of Hirschsprung’s disease.
An obstruction is most likely to be found in which portion of the gut?
A. Ascending colon
B. Ileocecal sphincter
C. Lower esophageal sphincter
D. Pylorus
E. Sigmoid colon
18. Mass movements in the large intestine cause which of the following?
A. Contraction of internal anal sphincter
B. Duodenal peristalsis
C. Gastric retropulsion
D. Hunger sensations
E. Rectal distention
19. Which of the following occur during the act of vomiting?
Lower Esophageal Upper Esophageal Abdominal Diaphragm
Sphincter Sphincter Muscles
A. Contract Contract Contract Contract
B. Contract Contract Relax Relax
C. Relax Contract Contract Relax
D. Relax Relax Contract Contract
E. Relax Relax Relax Relax
20. Which of the following best describes the direct physiological effect of the various
hormones on gastric emptying?
Gastrin Secretin CCK GIP Motilin
A. Decrease Decrease Decrease Decrease Increase
B. Increase Decrease None Decrease Increase
C. None None Decrease Increase Increase
D. None None Decrease None None
E. None None Increase None None
21. A 39-year-old man suffers from chest pain when he eats, especially when he eats meat.
He also belches excessively and has heartburn. His wife complains about his bad breath.
The radiograph shows a dilated esophagus, and achalasia is suspected. Esophageal