GI Flashcards
How does aspirin affect colorectal cancer?
Protective.
Increased COX2 linked to progression of adenoma to carcinoma. ASA is inhibits COX2 and is protective against polyp formation.
What is the affect of ACh on pancreatic B-cells?
Increased insulin secretion via M3 receptors
What is the affect of Glucagon on pancreatic B-cells?
Increased insulin secretion via Gs/Gq coupled receptors
What is the affect of B2 agonists on pancreatic B-cells?
Increased insulin secretion via Gs coupled receptors
What is the affect of GLP-like peptide on pancreatic B-cells?
Increased insulin secretion via Gs coupled receptors
What is the affect of A2 agonists on pancreatic B-cells?
Decreased insulin secretion via Gi coupled receptors
What is the affect of Somatostatin on pancreatic B-cells?
Decreased insulin secretion via Gi coupled receptors
What is the stool osmotic gap in a patient with lactase deficiency?
More H+ due to bacterial fermentation of lactose in gut
Increased osmotic gap because stool is more acidic
What is the H+ breath content in a patient with lactase deficiency?
Increased H+ on breath because of gut bacteria fermenting the lactose
How much energy (cals) comes from 1 g of protein?
4 cal
How much energy (cals) comes from 1 g of carbs?
4 cal
How much energy (cals) comes form 1 g of fat?
9 cal
What is the function of heme oxygenase?
Converts heme to biliverdin (green of bruises)
What are the main steps in B12 absorption?
B12 + R (haptocorrin, from saliva) B12/R cleaved by pancreatic enzymes in prox. duodenum B12 + IF (from gastric parietal cells) Bind IF receptor in terminal ileum B12 absoprtion
What is a GI risk of halothane administration for anesthesia?
DILI: drug induced liver injury
- Extensive hepatocellular damage
- Shrunken liven
- Increased ALT/AST & PTT
Where is iron absorbed?
Duodenum
Where is folate absorbed?
Jejunum, ileum
Where is B12 absorbed?
Terminal ileum (with bile salts)
CCK: source + action
I cells (duodenum, jejunum)
Increased secretions (pancreatic, gallbladder) Decreased gastric emptying
Gastrin: source + action
G cells (antrum of stomach)
Increased H+ secretion
Increased growth of gastric mucosa & motility
GIP: source + action
glucose-dependent insulinotropic peptide, aka gastric inhibitory peptide
K cells (duodenum, jejunum)
Exocrine: decreased H+ secretion
Endocrine: increased insulin secretion
Motilin: source + action
Small intestine
MMC
Secretin: source + action
S cells (duodenum)
Increased pancreatic HCO3- secretion
Increased bile secretion
Decreased gastric acid secretion
Somatostatin: source + action
D cells (pancreatic islets, GI mucosa)
Decreased gastric acid and pepsinogen secretion
Decreased pancreatic and small intestine fluid secretion
Decreased gallbladder contraction
Decreased insulin and glucagon release
(all around inhibitory!)
