in what condition are gastrin levels elevatedchronic PPI use, ☆chronic atrophic gastritis(H pylori, pernicious anemia), gastrinoma (Zollinger-Ellison syndrome) gastrointestinalUWorld SIM1 May 29, 2020, 9:15 AM HirotoShishido
pancreatic flow rate & levels of bicarbonate and chloride in pancreatic exocrine secretionsDuring low flow, the ductal cells secrete an isotonic solution containing low bicarbonate concentrations and higher chloride concentrations.
During high flow, the pancreas secretes an isotonic solutionthatis high in bicarbonate and low in chloride. (stimulated by secretin) gastrointestinalUWorld SIM1 May 26, 2020, 5:55 AM HirotoShishido
what synthesize bile acid☆cholesterol 7α-hydroxylase catalyzes the rate-limiting step in the synthesis of bile acids gastrointestinalUWorld May 22, 2020, 10:48 PM HirotoShishido
predisposing factor to cholesterol gallstone formationAs water-insoluble cholesterol is secreted in bile, it is rendered soluble in small amounts by the detergent action of these amphipathic (eg, hydrophobic and hydrophilic) bile salts and ☆phosphatidylcholine (a phospholipid).
When there is ☆more cholesterol than can be made soluble, it precipitates into crystals that eventually grow and merge to form gallstones. Gallbladder hypomotility further promotes cholesterol nucleation and gallstone formation. gastrointestinalUWorld May 21, 2020, 4:13 AM HirotoShishido
complications of gastroesophageal reflux disease(GERD)・Erosive esophagitis with esophageal ☆ulcers: often marked by a worsening of baseline GERD symptoms and the ☆development of odynophagia (painful swallowing).
・Barrett esophagus
・Esophageal stricture: typically develops in the setting of a healing esophageal ulcer when collagen fibers contract and cause narrowing of the esophageal lumen. Patients usually present with dysphagia and a sensation of food getting stuck in the esophagus. gastrointestinalUWorld May 20, 2020, 9:11 PM HirotoShishido
risk factors for gastric adenocarcinomaChronic H. pylori infection
Autoimmune chronic atrophic gastritis
Obesity
☆Salt-preserved food
N-nitroso-containing compounds(eg processed meat, tabacco) gastrointestinalUWorld May 16, 2020, 9:10 PM HirotoShishido
blood vessels involved in diverticular bleeding☆vasa recta
as the diverticula enlarge, the vessels are exposed to choronic injury leading to thinning of the vascular media gastrointestinalUWorld May 16, 2020, 9:00 PM HirotoShishido
scretin and cholecystokininsecretin
S cells, ☆↑pancreatic HCO3- secretion, ↓gastric acid secretion, ↑bile secretion
cholecystokinin
I cells, ☆pancreatic secretion, ↑gallbladder contraction, ↑sphincter Oddi relaxation, ↓gastric emptying gastrointestinalUWorld May 12, 2020, 9:00 AM HirotoShishido
Lavator ani muscle which facilitates defecation process¥puborectalis muscle
The puborectalis muscle, part of the levator ani muscle group, must be voluntarily relaxed to facilitate defecation. This patient most likely has pelvic dyssynergia, which leads to increased sphincter tonus and inability to empty the anal canal. Normally, defecation is enabled by simultaneous voluntary contraction of abdominal muscles and relaxation of the external anal sphincter and puborectalis muscle. gastrointestinalAmboss level4 May 9, 2020, 8:34 AM HirotoShishido
primary bacterial peritonitis(sponataneous bacterial peritonitis(SBP))
common and potentially fatal bacterial infection in patients with ¥cirrhosis and ascites
paracentesis with ascitic fluid neutrophil count> 250cells/mm3
LaxativesL is BOOSS
①Lubiprostone (chloride channel agonist)
②Bulk-forming (psyllium)(fiber-supplements)(bulky seaweed binds luminal water to decrease consistency of stool)
③Osmotic laxatives(PEG(polyethylene glycol) drain cover)(★lactulose, magnesium hydroxide)
④Opioid antagonist(eg ☆methylnaltrexone
→ doesn't cross BBB→ ☆doesn't induce withdrawal)
⑤Surfactant(canoe at the DOCK→docusate) reduces the surface tension of stool, enabling water and fat to enter and soften it
⑥Stimulant(bisacodyl, ... gastrointestinal国試直前UWorld May 6, 2020, 8:43 AM HirotoShishido
antidiarrheal agentsBOBOBo
①Bulk forming agents(psyllium, pectin)
(absorbs water from stool)
②Opioid agents
(slowing peristalsis by ☆inhibiting acetylcholine release from myenteric plexus neurons)
③Bismuth subsalicylate
(stimulates intestinal fluid absorption and inhibits prostaglandin synthesis (antispasmotic effect))
④Octreotide (somatostatin analog that reduces secretion of pancreatic and Gl hormones)
⑤Bile acid sequestrants (cholestyramine→ bile acid diarrhea) gastrointestinalpharmacologyUWorld May 6, 2020, 8:25 AM HirotoShishido
alminium hydroxide
magnesium hydroxideboth are antacids
AluMINIMUM amount of feces CHOPS
☆Constipation, Hypophosphatemia, Osteodystrophy, Proximal muscle weakness, Seizures
the fermentation of undigested lactose by gut bacteria→ production of short-chain fatty acid→ ☆acidify the stool (decreased stool pH)
→hydrogen gas is also produced, leading to ◯increased breath hydrogen content
→☆elevated stool osmolality gastrointestinalbiochemistryUWorld May 5, 2020, 8:15 AM HirotoShishido
hereditary pancreatitisTrypsin can serve as its own inhibitor by cleaving active trypsin molecules at a second site, rendering them inactive.
(Serine peptidase inhibitor Kazal-type 1 (SPINK1) is secreted by pancreatic acinar cells and functions as a trypsin inhibitor)
Hereditary pancreatitis results from mutations involving the ☆trypsinogen or SPINK1 gene. The most common mutation leads to the production of abnormal trypsin that is ☆not susceptible to inactivating cleavage by trypsin. gastrointestinalUWorld May 5, 2020, 7:40 AM HirotoShishido
