gastrointestinal Function Flashcards
Chronic administration of which of the following type of drugs would lead to a sustained increase in serum gastrin levels
Proton pump inhibitors
Which of the following statements about small intestinal motility is correct
Contractile activity is initiated in response to bowl wall distention
Which one of the following statements about gastric emptying is correct
Vagotomy decreases accommodation of the proximal stomach
Vitamin B12 is absorbed primarily in the
Ileum
The principal paracrine secretion involved in the inhibitory feedback regulation of gastric acid secretion is
Somatostatin
Which one of the following is the putative inhibitory neurotransmitter responsible for relaxation of gastrointestinal smooth muscle
Vasoactive intestinal peptide (VIP)or NO
Which one of the following statements best describes water and electrolyte absorption in the GI tract
The majority of absorption occurs in the jejunum
Which of the following statements is NOT true
The force of contraction of gastric smooth muscle is independent of the presence of action potentials on top of the slow waves
The hormone involved in the initiation of the migrating motor complex is
Motilin
The rate of gastric emptying increases with an increase in
Intragastric volume
Basal acid output is increased by
Alkalinization of the antrum
Which one of the following processes applies to the proximal stomach
Accommodation
After secretion of trypsinogen into the duodenum,the enzyme is converted into its active form,trypsin by
Enteropeptidase
Pharmacological blockade of histamine H2 receptors in the gastric mucosa
Inhibits both gastrin-and acetylcholine-mediated secretion of acid
Removal of proximal segments of the small intestine results in a decrease in
Pancreatic enzyme secretion
Dietary fat,after being processed,is extruded from the mucosal cells of the gastrointestinal tract into the lymphatic ducts in the form of
Chylomicrons
Gas within the colon is primarily derived from which one of the following sources
Fermentation of undigested oligosaccharides by bacteria
Which of the following has the highest pH
Pancreatic juice
Contraction of the gallbladder is correctly described by which of the following statements
It occurs in response to cholecystokinin
Acidification of the duodenum will
Decrease gastric emptying
Which of the following sugars is absorbed from the small intestine by facilitated diffusion
Fructose
Nearly all binding of cobalamin (vitamin B12)to intrinsic factor occurs in the
Stomach
Secretion of H+by gastric parietal cells occurs by which of the following processes
Primary active transport
Which statement about gastric motility is NOT correct
Secretin,a hormone released by the duodenum,acts to increase the rate of gastric emptying
The origin of electrical slow wave activity in gastrointestinal tract smooth muscle is
The intestinal cells of Cajal
The major factor that protects the duodenal mucosa from damage by gastric acid is
Pancreatic bicarbonate secretion
Bicarbonate absorption from the upper small intestine is closely coupled with
Na-glucose absorption
The migration motor complex in humans
Requires an intact intrinsic nervous system for coordinated propagation
The delivery of chyme into the proximal small intestine will
Increase small intestine segmentation
The paracrine secretion responsible for inhibiting gastric acid secretion is
Somatostatin
Which of the following is the site of secretion of intrinsic factor
Gastric fundus
Cholecystokinin (CCK)inhibits
Gastric emptying
Which of the following abolishes “receptive relaxation “of the stomach
Vagotomy
Secretion of which of the following substances is inhibited by low pH
Gastrin
Which of the following is the site of secretion of gastrin
Gastric antrum
Which of the following is characteristic of saliva
Hypotonicity relative to plasma
Which of the following is true about the secretion from the exocrine pancreas
Pancreatic enzyme secretion is increased by cholecystokinin (CCK)
Which of the following substances must be further digested before it can be absorbed by specific carriers in intestinal cells
Sucrose
Slow waves in small intestinal smooth muscle cells are
Oscillating resting membrane potentials (membrane potential that cycle between depolarizations and repolarizations)
Peristalsis of the small intestine
Involves contraction of smooth muscle behind the food bolus and relaxation of smooth muscle in front of the bolus
A patient with a duodenal ulcer is treated successfully with the drug cimetidine. The basis
Blocks H2 receptors on parietal cells
When parietal cells are stimulated, the secrete
HCL and intrinsic factor
Which of the following is the site of Na+—-bile acid cotransport
Ileum
The pathway from the intestinal lumen to the circulating blood for a short-chain fatty acid
Intestinal mucosal cell——>hepatic portal vein blood———->systemic venous blood
Water is absorbed in the jejunum,ileum, and colon and excreted in the feces.Arrange these in order of the amount of water absorbed or excreted from greatest to smallest
Jejunum,ileum,colon,feces
Which of the following statements is FALSE
Distention of the body and fundus elicit reflexes that inhibit HCl secretion
