PHY 503: GI PRINCIPLES, HORMONAL FUNCTIONS, NEURAL
FUNCTIONS: TEST QUESTIONS WITH ACCURATE ANSWERS
What is GLIP and what does it do? -- Answer ✔✔ substance secreted by
duodenal/proximal jejunal K cells in response to glucose ingestion (before food gets to
the SI), and it stimulates insulin release and inhibits acid secretion
What is motilin and what does it do? -- Answer ✔✔ hormone released from
duodenal/proximal jejunal M cells during fasting, and it increases gastric emptying during
the time in between meals (interdigestive period)
What hormones are part of the gastrin family? -- Answer ✔✔ gastrin and CCK
What hormones are part of the secretin family? -- Answer ✔✔ secretin, GLIP, and
glucagon-like peptide 1 (GLP-1)
What are the 6 sphincters of the GI tract? -- Answer ✔✔ upper esophageal, lower
esophageal, pyloric, ileocecal, internal anal, external anal
What are the 4 layers of the GI tract? -- Answer ✔✔ serosa, muscularis, submucosa,
mucosa
, What is somatostatin and what does it do? -- Answer ✔✔ peptide hormone secreted
from gastric/duodenal D cells and pancreatic delta cells that directly inhibits acid
secretion and mediates acid-induced inhibition of gastrin release; it is inhibited by ACh
What is histamine and what does it do? -- Answer ✔✔ stimulator of parietal cells that is
released from ECL cells in the corpus, acting as a paracrine on neighboring parietal cells
to stimulate acid release
What does vasoactive intestinal peptide (VIP) do? -- Answer ✔✔ promotes relaxation of
GI smooth muscle and stimulation of fluid/electrolyte secretion in the intestine
What does gastrin-releasing peptide (GRP) do? -- Answer ✔✔ triggers release of gastrin
from G cells
What do enkephalins do? -- Answer ✔✔ block pain transmission by binding to opioid
receptors, and trigger increased smooth muscle tone which reduces GI motility
What are enteroendocrine cells? -- Answer ✔✔ endocrine and neurocrine cells that
physically connect to enteric neurons
Why can SSRIs cause GI side effects? -- Answer ✔✔ because 95% of the body's
serotonin is found in the gut
What are the two main nerve plexuses in the enteric NS? -- Answer ✔✔ myenteric and
submucosal
FUNCTIONS: TEST QUESTIONS WITH ACCURATE ANSWERS
What is GLIP and what does it do? -- Answer ✔✔ substance secreted by
duodenal/proximal jejunal K cells in response to glucose ingestion (before food gets to
the SI), and it stimulates insulin release and inhibits acid secretion
What is motilin and what does it do? -- Answer ✔✔ hormone released from
duodenal/proximal jejunal M cells during fasting, and it increases gastric emptying during
the time in between meals (interdigestive period)
What hormones are part of the gastrin family? -- Answer ✔✔ gastrin and CCK
What hormones are part of the secretin family? -- Answer ✔✔ secretin, GLIP, and
glucagon-like peptide 1 (GLP-1)
What are the 6 sphincters of the GI tract? -- Answer ✔✔ upper esophageal, lower
esophageal, pyloric, ileocecal, internal anal, external anal
What are the 4 layers of the GI tract? -- Answer ✔✔ serosa, muscularis, submucosa,
mucosa
, What is somatostatin and what does it do? -- Answer ✔✔ peptide hormone secreted
from gastric/duodenal D cells and pancreatic delta cells that directly inhibits acid
secretion and mediates acid-induced inhibition of gastrin release; it is inhibited by ACh
What is histamine and what does it do? -- Answer ✔✔ stimulator of parietal cells that is
released from ECL cells in the corpus, acting as a paracrine on neighboring parietal cells
to stimulate acid release
What does vasoactive intestinal peptide (VIP) do? -- Answer ✔✔ promotes relaxation of
GI smooth muscle and stimulation of fluid/electrolyte secretion in the intestine
What does gastrin-releasing peptide (GRP) do? -- Answer ✔✔ triggers release of gastrin
from G cells
What do enkephalins do? -- Answer ✔✔ block pain transmission by binding to opioid
receptors, and trigger increased smooth muscle tone which reduces GI motility
What are enteroendocrine cells? -- Answer ✔✔ endocrine and neurocrine cells that
physically connect to enteric neurons
Why can SSRIs cause GI side effects? -- Answer ✔✔ because 95% of the body's
serotonin is found in the gut
What are the two main nerve plexuses in the enteric NS? -- Answer ✔✔ myenteric and
submucosal
