GI Flashcards
How is D-xylose absorbed?
Monosaccharide - by brush border enzymes.
Does NOT need pancreatic amylase.
Gastric erosion vs. ulcer?
Erosion - does NOT extend past muscularis mucosa
Ulcer - extends PAST muscularis mucosa into submucosal layers
How does Diphtheria present and pathogenesis?
Diphtheria - AB exotoxin which ribosylates EF2 - inhibiting protein synthesis and causing cell death.
Presents as someone who moved here (without vaccine), grayish pharyngeal exudate, enlarged LAD, partial soft palate paralysis
Presentation of cancer in the head of the pancreas? Most impt RF?
Jaundice
Progressive weight loss, Anorexia
Courvoisier sign (palpable but nontender gallbladder)
Obstructive jaundice (dark urine, pale stools)
RF: Smoking!
What is superior mesenteric artery syndrome?
Transverse portion of the duod gets trapped btwn aorta and SMA, causing SBO.
What disease can cholestasis cause?
Osteomalacia.
Cholestasis (deposition of bile pigment within the liver) -> reduction in bile flow -> malabsorption of vit ADEK -> osteomalacia
In liver disease (such as alcoholic cirrhosis), which factor will be deficient first and therefore cause an increase in what time (PT or PTT)?
Factor VII
PT
What do they secrete and where are they located?
Parietal Cells
Chief Cells
Parietal: HCL and intrinsic factor - superficial gastric glands
Chief: Pepsinogen - deeper gastric glands
Q124
Pancreatic pseudocyst lined with?
Fibrous granulation tissue.
Not true cyst bc no epithelium on the inside. in acute pancreatitis, pancreatic enzymes leak out and induces inflammation leading to granulation tissue to wall it off. Takes about 4-6 wks after the acute episode.
HNPCC - what gene mutated?
DNA mismatch repair. 1 mutated allele inherited; another hit during life.
Lynch I: just colon cx
Lynch II: colon + extraintestinal
Cause of duodenal atresia vs. intestinal (jejunal, ileal, colonic) atresia
Duod = failure of recanalization Intestinal = vascular accident in utero. diminished perfusion -> ischemia. can result in "apple core" spiral config around a vessel distal portion.
Ulcer in which location has least risk of malignancy?
Duodenum
Anal fissure most commonly found?
Posterior Midline distal to the dentate line
P's: Below the Pectinate line Pain while Pooping Blood on toilet Paper Located Posteriorly cuz this area is Poorly Perfused.
What structures develop from ventral bud vs. dorsal bud of pancreas?
Ventral = head, main pancreatic duct, uncinate process Dorsal = body, tail, isthmus, accessory pancreatic duct
How should B12 be administered in those with B12 deficiency anemia?
Parenteral.
Most cases of B12 def are due to poor absorption and dietary B12 def is much less common.
How does the liver take up unconjugated bili from the blood vs. secreting conjugated bili into biliary system?
Unconjugated bili -> Liver = PASSIVE.
OATP (organic anion transporting polypeptide)
Conjugated bili -> Biliary System = ACTIVE
MRP2 (organic anion transporter that uses ATP)
If this energy-dependent transporter is inhibited, will develop a conjugated hyperbilirubinemia, with increased excretion of conj, bili into the urine.
Colonic diverticula form by what mechanism?
Pulsion - increased intraluminal pressure, such as straining when constipated.
Clinical manifestations of diffuse esophageal spasm mimic what condition?
Angina (Chest pain) + Intermittent dysphagia .
Elevated transaminases (viral serologies neg) + neurologic sx = What?
Wilson’s disease!
Can get slit lamp to get for kaiser fleischer rings. >.>
What are the portocaval anastomoses?
Esophagus: L gastric esophageal vein
Umbilical: Paraumblical epigastric
Rectal: Superior rectal Inf and Middle Rectal
When does a carcinoid tumor present as carcinoid syndrome?
Mets to the Liver or Extraintestinal, like Lung.
Intestinal Carcinoid products are metabolized by the liver, so they don’t lead to symptoms.
Wilson’s. How is Cu normally secreted from the body?
Hepatic secretion into bile -> stool.