Chapter 27. Digestion & Absorption of Nutrients
In governing peristalsis, which of the following directions of nerve impulses and neurotransmitter is correctly matched?
B. Retrograde; nitric oxide
C. Anterograde; glutamate
D. Anterograde; nitric oxide
E. Anterograde; acetylcholine
Conversion of the basic electrical rhythm to an increase in intestinal muscle tension is produced by which of the following?
A. Activation of interstitial cells of Cajal
C. Release of acetylcholine
E. Inhibition of nitric oxide synthase
The migrating motor complex is triggered by which of the following?
A patient is referred to a gastroenterologist because of persistent difficulties with swallowing. Endoscopic examination reveals that the lower esophageal sphincter fails to fully open as the bolus reaches it, and a diagnosis of achalasia is made. During the examination, or in biopsies taken from the sphincter region, a decrease would be expected in which of the following?
A. Esophageal peristalsis
B. Expression of neuronal NO synthase
C. Acetylcholine receptors
E. Contraction of the crural diaphragm
Gastric pressures seldom rise above the levels that breach the lower esophageal sphincter, even when the stomach is filled with a meal, due to which of the following processes?
D. Stimulation of the vomiting center
The physiological gastric pressure response to feeding described in Question 5 could be partly inhibited experimentally by all of the following treatments except
A. cholinergic antagonist.
B. nitric oxide synthase inhibitor.