Term
Vertebral level:
Celiac trunk
SMA
L renal artery
Gonadal arteries
IMA
Bifurcation of aorta |
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Definition
Celiac: T12
SMA: L1
Left renal: L1 (slightly lower than right)
Gonadals: L2
IMA: L3
Bifurcation: L4 |
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Term
Gastrin
Source?
Action?
Regulation? |
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Definition
G cells (antrum)
Increase H+ secretion, growth of gastric mucosa, gastric motility
Stomach distension/alkalinization, amino acids (esp. Phe and Trp), vagal stimulation. Inhibited by pH < 1.5 |
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Term
Cholecystokinin
Source?
Action?
Regulation? |
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Definition
I cells (duodenum, jejunum)
Increase pancreatic enzyme secretion, gallbladder constriction, sphincter of Oddi relaxation. Decrease gastric emptying. Uses muscarinic pathways.
Stimulated by fatty acids, AAs. |
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Term
Secretin
Source?
Action?
Regulation? |
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Definition
S cells (duodenum)
Increase pancreatic bicarb secretion, bile secretion. Decrease gastric acid secretion. Need higher pH for pancreatic enzymes to function.
Stimulated by acid, fatty acids, in duodenal lumen. |
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Term
Somatostatin
Source?
Action?
Regulation? |
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Definition
D cells (pancreatic islets, GI mucosa)
Decrease gastric acid and pepsinogen, decrease pancreatic and small intestine fluid secretion, inhibit gallbladder contraction, decrease insulin and glucagon release. All around inhibitory, also has anti-growth hmn effects; used for acromegaly.
Stimulated by acid, inhibited by vagal stimulation. |
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Term
Glucose-dependent insulinotropic peptide (GIP)
Source?
Action?
Regulation? |
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Definition
K cells (duodenum, jejunum)
Decreases gastric acid secretion, increases insulin release. *This is why oral glucose load used faster than same amount IV.
Increased by oral glucose, fatty acids, amino acids. |
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Term
Vasoactive Intestinal Peptide (VIP)
Source?
Action?
Regulation? |
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Definition
Parasympathetic ganglia in sphincters, GB, SI.
Increases water and electrolyte secretion, increases sphincter relaxation.
Stimulated by distention and vagal action, inhibited by adrenergic input. |
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Term
| Why does atropine block vagal stimulation of parietal cells, but not G cells? |
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Definition
G cells are stimulated by vagus with GRP, not ACh.
Note that gastrin primarily affects ECL cells, which then affect parietal cell acid secretion via H2. |
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Term
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Definition
Transmural esophageal rupture due to retching.
Similar to Mallory-Weiss, which is just mucosal lacerations. |
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Term
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Definition
| Gastric hypertrophy with protein loss, parietal cell atrophy, increase in mucous cells. Precancerous. Rugae of stomach so hypertrophied, they look like brain gyri. |
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Term
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Definition
Congenital megacolon due to failure of neural crest cell migration.
Always involves rectum (last place to migrate to!) Failure to pass meconium. Dilated colon proximal to aganglionic segment.
Increased risk in Down syndrome. |
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Term
| Intestinal angiodysplasia |
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Definition
| Tortuous dilation of vessels leading to GI bleed. More common in older patients. Cecum, terminal ileum, and ascending colon. |
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Term
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Definition
| Sporadic lesions in children < 5 yrs. Mostly in rectum. If solitary, no cancer risk. If multiple, juvenile polyposis syndrome, increased adenocarcinoma risk. |
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Term
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Definition
Autosomal dominant. Tumor suppressor gene SKT11/LKB1 (19).
Multiple benign hamartomas throughout GI tract, along with hyperpigmented mouth, lips, hands, genitalia. Associated with increased colon cancer risk and other malignancies. |
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Term
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Definition
| FAP + malignant CNS tumor. (TURcot = TURban) |
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Term
| NOD2 and NF-kappaB in Chron's? |
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Definition
| NOD2 is mutated in some Chron's, (nucelotide-binding oligomerization domain). An intracellular microbial receptor. Triggers NF-kappaB pathway, which increases cytokine release in response to infectious pathogens. |
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Term
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Definition
| Lined by fibrous and granulation tissue. Not a "true" cyst because does not have epithelial walls. High pancreatic enzyme content. A complication of pancreatitis. Takes 4- 6 weeks to "mature" (thicken) after pancreatitis. |
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