shosh: GI

  1. Which ligament contains the portal triad?
  2. What does the falciform ligament contain, and what fetal structure is it derived from?
    Ligamentum teres, derived from the fetal umbilical ligament
  3. Which layer of the gut is Meissner's plexus found in?
  4. Which layer of the gut is Auerbach's plexus found in?
    Muscularis externa
  5. Level of celiac trunk
  6. Level of SMA
  7. Level of IMA
  8. Level of bifurcation of aorta
  9. Artery that can be eroded by duodenal ulcer
    Gastroduodenal branch of common hepatic
  10. Anastamoses that develop if abdominal aorta is blocked
    • Internal thoracic (subclavian)--epigastrics
    • Superior pancreaticoduodenal (SMA)--inferior pancreaticoduodenal (IMA)
    • Middle colic (SMA)--left colic (IMA)
    • Superior rectal (IMA)--middle rectal (internal iliac)
  11. Three portal systemic anastomoses and the their clinical symptoms
    • Left gastric--esophageal (esophageal varices)
    • Paraumbilical--superior and inferior epigastrics (caput medusae)
    • Superior rectal--middle and inferior rectal (internal hemorroids)
  12. Zone of liver most vulnerable to toxic and ischemic injury
    Zone III, around central vein (poorly perfused)
  13. Structures found in femoral sheath
    Femoral artery, vein, and deep inguinal lymph nodes (not femoral nerve)
  14. Indirect inguinal hernia
    • Enters internal inguinal ring lateral to epigastric artery
    • Occurs in infants due to failure of processus vaginalis to fuse
  15. Direct inguinal hernia
    • Protrudes through inguinal triangle (borders are femoral nerve, sartorious muscle, and inguinal ligament), medial to inferior epigastric artery
    • Seen in older men
  16. Femoral hernia
    • Protrudes under inguinal ligament, lateral to pubic tubercle
    • More common in women
  17. GIP
    • Secreted from K cells of the duodenum
    • Decreases gastric acid secretion
    • Increases insulin secretion
    • Release is activated by oral glucose (which triggers insulin secretion more effectively than IV glucose)
  18. Functions of VIP
    • Increases electrolyte and water secretion in the intestine
    • Relaxes intestinal smooth muscle and sphincters
  19. Cells that secrete gastric acid
    Parietal cells of stomach
  20. Regulation of gastric acid secretion
    • Upregulated by gastrin, ACh, and histamine
    • Downregulated by somatostatin, GIP, prostaglandins, and secretin
  21. Effect of atropine on stomach secretions
    • Inhibits vagal stimulation of parietal cells, blocking gastric acid and B12 release
    • Does not affect G cells that release gastrin, since G cells are activated by GRP, not ACh
  22. Mechanism of gastrin-mediated acid increase
    Gastrin acts primarily on ECL cells, causing them to release histamine, which triggers parietal cells to release acid. Its direct effect on parietal cells is minimal
  23. Gland that secretes the most mucinous saliva
  24. Intracellular effect of prostaglandins on parietal cells
    Decrease intracellular cAMP, which inhibits acid secretion
  25. Only submucosal glands found in the GI tract
    • Brunner's glands, located in duodenal submucosa
    • Secrete alkaline mucus to neutralize acid gastric contents entering duodenum
    • Hypertrophy in peptic ulcer disease
  26. Trypsinogen
    • Secreted from the pancreas, activated to trypsin by enterokinase on the intestinal brush border
    • Function is to activate other pancreatic proenzymes
  27. Three steps to carbohydrate digestion
    • Salivary amylase hydrolyzes alpha 1,4 linkages to yield disaccharides
    • Pancreatic amylase hydrolyzes starch into di/oligosaccharides
    • Oligosaccharide hydrolases on intestinal brush border produce monosaccharides (rate limiting step)
  28. Where are divalent cations (iron, magnesium, calcium) absorbed?
  29. Where is folate absorbed?
  30. Where are B12 and bile acids absorbed?
  31. Enzyme that converts unconjugated bilirubin to conjugated bilirubin
    UDP glucouronyl transferase
  32. Warthin's tumor
    A benign mass of salivary gland tissue trapped in a lymph node
  33. Increased risk of esophageal carcinoma
    Associated with achalasia
  34. Lye ingestion
    Associated with esophageal strictures
  35. Pathogens that invade the esophagus
    HSV1, CMV, candida
  36. Plummer-Vinson syndrome
    Triad of dysphagia, due to esophageal webs, glossitis, and iron-deficiency anemia
  37. Dermatitis herpitiformis
    Associated with celiac
  38. Patient presents with arthralgia and cardiac and neural symptoms. Biopsy shows PAS positive macrophages in the intestinal lamina propria
    Whipple's disease, infection with T. whippelli
  39. Menetrier's disease
    Gastric hypertrophy with parietal cell atrophy. Precancerous
  40. Enlargement of the left supraclavicular lymph node
    Virchow's node, may indicate gastric adenocarcinoma
  41. Most likely cause of a duodenal ulcer
    H. pylori
  42. Most common site of Crohn's manifestations
    Terminal ileum and colon
  43. Most common site of UC involvement
    End of the GI tract--the rectum is always involved
  44. Transmural v. mucosal inflammation in inflammatory bowel disease
    • Crohn's--transmural inflammation
    • UC--submucosal inflammation
  45. Inflammatory bowel disease with granulomas
  46. Extraintestinal manifestations of Crohn's
    • Migratory polyarthritis
    • Erythema nodosum
    • Ankylosing spondylitis
    • Uveitis
  47. What is primary sclerosing cholangitis associated with?
  48. Mechanism of gallstone formation in Crohn's
    Impaired bile acid reabsorption from the terminal ileum increases cholesterol concentration in the bile
  49. Mechanism of renal stones in Crohn's
    • Normally, Ca binds to oxalate in the GI tract and inhibits its absorption
    • In Crohn's, Ca levels are low
    • Lack of Ca increases oxalate absorption, resulting in the formation of Ca-oxalate stones
  50. Most common cause of appendicitis in children
    Lymphoid hyperplasia, usually following a viral infection
  51. Most common cause of appendicitis in adults
  52. Most common location for a diverticulum
    Sigmoid colon
  53. Zenker's diverticulum
    • Herniation of mucsoal tissue at pharyngoesophageal junction
    • False diverticulum, does not involve all 3 gut layers
    • Presents with halitosis and dysphagia
  54. Meckel's diverticulum
    • Persistence of the vitelline duct or yolk sac
    • True diverticulum
    • May contain ectopic acid-secreting gastric tissue, which can cause bleeding ulcers (bloody stools)
    • Usually presents in first two years of life
  55. Virus that can trigger intussusception of the bowel in children
  56. Duodenal atresia
    • Failure of duodenum to recanalize during embryonic development
    • Presents with early bilious vomiting
    • Associated with Down's
  57. Most common locations of ischemic colitis
    Splenic flexure and distal colon
  58. Gene mutations associated with colon cancer
    • APC--early mutation
    • K-ras--seen in late adenomatous polyps
    • p53--late mutation in adenocarcinoma
  59. Hyperplastic polyp
    • Most common non-neoplastic colon polyp
    • Most often found in rectosigmoid colon
  60. Peutz-Jeghers syndrome
    • AD syndrome
    • Multiple, non-malignant hamartomatous polyps in GI tract, with increased risk of colorectal cancer
    • Hyperpigmentation of mouth, hands, and genitalia
  61. FAP
    • AD mutation in APC gene leads to unregulated beta catenin activity
    • Many, many colon polyps
    • Always involves rectum
  62. Gardener's syndrome
    FAP plus bone tumors and retinal hyperplasia
  63. Lynch syndrome
    • Autosomal dominant mutation resulting in mismatch repair
    • Always involves proximal colon
  64. Apple core lesion on barium enema X-ray
    Colorectal cancer
  65. Will a non-metastatic carcinoid tumor in the GI tract be asymptomatic?
    No, because serotonin is metabolized in the liver
  66. ALT is much higher than AST
    Viral hepatitis
  67. AST is much higher than ALT
    Alcoholic hepatits (remember that AST is a mitochondrial enzyme)
  68. Elevated GGT
    Alcohol abuse
  69. Elevated alk phos
    Obstructive liver disease, bone disease, bile duct disease
  70. Elevated amylase
    • Acute pancreatitis
    • Mumps
  71. Low ceruloplasmin
    Wilson's disease
  72. Viruses associated with Reye's syndrome
    VZV, influenza B
  73. Mechanism of Reye's disease
    Aspirin metabolites decrease beta oxidation of fatty acids by reversible inhibition of mitochondrial enzymes
  74. Most likely cause of a liver tumor
  75. Factors associated with increased incidence of hepatocellular carcinoma
    • Hep B and C
    • Wilson's disease
    • Hemochromatosis
    • Alpha 1 antitrypsin deficiency
    • Alcoholic cirrhosis
    • Aflatoxins
  76. Budd-Chiari syndrome
    • Obstruction of the hepatic vein (may be due to IVC obstruction or right heart failure)
    • Presents with a triad of abdominal pain, ascites, and hepatosplenomegaly
    • Associated with polycythemia vera, pregnancy, and hepatocellular carcinoma
  77. Alpha 1 antitrypsin deficiency
    • Co-dominant inheritance, causes a misfolded gene product
    • Panacinar emphysema and increased risk of HCC
    • PAS positive intracellular inclusion bodies seen in liver
  78. Cause of physiologic neonatal jaundice
    • Immature UDP glucouronyl transferase
    • Treat with phototherapy to convert unconjugated bilirubin to a water soluble form
  79. Obstructive jaundice causes an increase in which form of bilirubin?
  80. Hemolytic jaundice causes an increase in which form of bilirubin?
    Unconjugated (not water soluble)
  81. Gilbert's syndrome
    • Mild decrease in UDP glucouronyl transferase
    • Elevated unconjugated bilirubin during stress (e.g. fasting, infection)
    • Benign
  82. Crigler-Najjar type I
    • Absent UDP glucouronyl transferase
    • Presents with increased unconjugated bilirubin, jaundice, and kernicterus
    • Patients typically die within a few years
    • (Type II is a mild form of Crigler-Najjar that can be treated with barbiturates)
  83. Dubin-Johnson syndrome
    • Defective bilirubin excretion causes conjugated hyperbilirubinemia
    • Liver is black
    • Asymptomatic
  84. Symptoms of Wilson's disease
    • Low ceruloplasmin, high copper
    • Asterixis
    • Basal ganglia degeneration, giving rise to Parkinson-like symptoms
    • Cirrhosis
    • Kaiser-Fleischer rings
    • Heptaocellular carcinoma
    • Dementia
    • Hemolytic anemia
    • Renal tubular acidosis
  85. Treatment for Wilson's disease
    Penicillamine or trientine
  86. Classic triad of hemochromatosis
    • Diabetes mellitus
    • Micronodular cirrhosis
    • Hyperpigmentation
    • (also causes CHF--major cause of death)
  87. Primary biliary cirrhosis
    • Autoimmune destruction of the bile ducts with lymphocytic infiltrate and granuloma formation
    • Anti-mitochondrial antibodies in serum
    • Hypercholesterolemia, steatorrhea, jaundice, dark urine, light stool
  88. Conditions associated with primary biliary cirrhosis
    • CREST
    • Celiac
    • Rheumatoid arthritis
  89. Primary sclerosis cholangitis
    • Concentric fibrosis of the bile ducts with onion skin appearance
    • Pattern of alternating strictures and dilations gives rise to "beading" appearance
    • Presents with pruritus, jaundice, light stool, and dark urine
    • Associated with ulcerative colitis and high serum IgM
  90. Substances that keep cholesterol dissolved in the gall bladder
    • Bile acids
    • Lecithin
  91. Effect of progesterone on the gall bladder
    Progesterone inhibits gall bladder motility and decreases bile acid secretion, predisposing to gall stones
  92. Pigment bile stones
    Radioopaque (unlike cholesterol stones), seen in patients with chronic hemolytic anemia
  93. Palpable, non-painful gall bladder
    Pancreatic tumor obstructing bile duct
  94. Analgesic of choice for treating cholecystitis
    Meperidine, which, unlike most opiates, does not cause the sphincter of Oddi to spasm
  95. Two most common causes of pancreatitis
    Gall stones, alcohol abuse
  96. Markers of pancreatic cancer
    CEA, CA-19
  97. Signs of pancreatic cancer
    • Abdominal pain radiating to the back
    • Weight loss
    • Obstructive jaundice with palpable gall bladder
    • Migratory thrombophlebitis (redness and tenderness of extremities on palpation)
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shosh: GI