GI Flashcards
classic paraneoplastic symptoms of small intestine carcinoid tumor?
heart murmur, hepatomegaly, flushing w hypoTN
-rosettes on histo
What is the best drug for hepatic encephalopathy?
lactulose (traps ammonia)
What are the findings for esophagus w Scleroderma?
decreased LES tone + decreased peristalsis
What are the hallmarks of abetalipoproteinemia (Apo B def)?
Chronic mal-absorption leading to signs of severe vitamin deficiencies (retinal degeneration, ataxia, motor dysfunction) + acanthocytosis + low cholesterol
-acanthocyte = RBC w spiny projections
Which nerve structures increase acid production in the stomach?
vagal trunks (parasymp)
What causes hereditary hemochromatosis (bronze diabetes)?
increased intestinal Fe absorption in the small intest
How does alcohol cause acetaminophen toxicity?
induces cytochrome p450 = increased hepatotoxic metabolites
What are the symptoms of a VIPoma?
Copious Watery Diarrhea, Hypokalemia, and Achlorhydria, hyperglycemia, flushing (vasodilation), big poop
If smoking can cause adenocarcinoma and squamous cell carcinoma, how to differentiate?
Adenocarcinoma is most common in non-smokers; so smoker = SCC
What is the Hallmark Triad of Plummer-Vinson syndrome?
Dysphagia (esophageal webs), glossitis, iron deficiency anemia
-others: angular stomatitis, spoon-shaped nails
What is Necrotizing enterocolitis
Necrosis of intestinal mucosa (primarily colonic)
- premature formula-fed infants
- colic + bloody diarrhea in the first week of life
Which branches of the abdominal aorta supplies blood to the spleen?
AA –> celiac trunk –> splenic artery –> spleen
Which drugs are MOS def used to treat mild-to-moderate Ulcerative colitis?
Mesalamine
Olsalazine
Sulfasalazine
What affect does atropine have on gastrin, Ach, and histamine to secrete acid from parietal cells?
Gastrin, Ach, and histamine are synergistic, so Atropine DECREASES acid production in all of them.
What is steatorrhea and its cause?
Bulky, oily, malodorous stool from bacterial overgrowth (acting on undigested lipids)
What is secretory diarrhea and its cause?
Large vol of watery stool; does not stop w fasting; caused by infectious agents transporting electrolytes into the lumen
What is osmotic diarrhea and its cause?
Watery diarrhea + bloating, gas that does NOT stop w fasting; caused by malabsorption
What is the difference between direct and indirect bilirubin?
direct: conjugated by the liver = soluble
indirect: not removed from blood by liver yet = insoluble
Which enzyme conjugates bilirubin?
UDP-glucuronosyltransferase
What is Crigler-Najjar Syndrome?
Absent UDP-glucuronosyltransferase =
jaundice, kernicterus (bilirubin deposition in brain), unconjugated bilirubin.
Tx: plasmapheresis and phototherapy.
What drug is used to treat carcinoid syndrome?
Octreotide (helps w the flushing and diarrhea)
The splenic artery and vein travel with which ligament?
splenorenal ligament
Which 3 arteries come off the celiac trunk?
splenic
left gastric
common hepatic
Which artery supplies the body & tail of the pancreas?
splenic artery
What is the MOA of the preferred drug to treat cholesterol gallstones?
ursodiol = decreases cholesterol synthesis, secretion, and absorption
What is primary biliary cirrhosis?
Autoimmune reaction (anti-mitochondrial abs) = lymphocytic infiltrate + granulomas --> destruction of intralobular bile ducts.
-assoc w other autoimmunes
What are the mesodermal defects assoc w tracheoesophageal atresia?
VACTERL: Vertebral defects Anal atresia Cardiac defects Tracheo-Esophageal fistula Renal defects Limb defects (bone and muscle)
Which drug is contraindicated in pts with alcohol disorder?
metronidazole bc it causes disulfiram rxn w alcohol
acetaldehyde accumulates, contributing to hangover symptoms
Reye syndrome affects which organelles?
mitochondria
What is the cause of duodenal atresia and its hallmarks?
cause: fail of recanalization of duodenal lumen
hallmarks: assoc w Down syndrome & “double bubble” on xray
How does H.pylori damage the gastric mucosa?
By increasing mucosal levels of ammonium
Which structures are retroperitoneal?
SAD PUCKER:
Suprarenal (adrenal) glands
Aorta and IVC
Duodenum (2nd through 4th parts)
Pancreas (except tail) Ureters Colon (descending and ascending) Kidneys Esophagus (thoracic portion) Rectum (partially)
Whats the general function of the duodenal hormones?
They decrease acid secretion rates
What are the hormones secreted by the duodenum?
prostaglandin E2
somatostatin
secretin
gastric inhibitory peptide (GIP)
What is biggest consequence of duodenal resection?
loss of inhibitory hormones = increase in acid secretion
Your pt has cholecystitis but no jaundice, where do you suspect stones?
Cystic duct or gallbladder (less common)
Your pt has cholecystitis and jaundice, where do you suspect stones?
Common bile duct
Whats the MOA of -azole antifungals?
inhibit fungal cytochrome P-450 lanosterol 12-a-demethylase
Where is the abnormal APC gene located for Familial adenomatous polyposis (FAP)?
5q21
Which artery supplies the DISTAL lesser curvature? the PROXIMAL lesser curvature?
distal: right gastric (dr)
proximal: left gastric (pl)
How does gastrin strengthen the mucosal barrier?
Gastrin release initiates cell division in proliferative zone of gastric mucosa
What is primary sclerosing cholangitis? What other diseases is it associated with?
PSC: concentric “onion skin” bile duct fibrosis w alternating strictures and dilation (=“beading” of intra- and extrahepatic bile ducts)
-assoc w ulcerative colitis
Which nerve is responsible for the defecation reflex?
pelvic splanchnic nerve
What is Ménétrier disease?
Gastric hyperplasia of mucosa = hypertrophied rugae
excess mucus production –> protein loss and parietal cell atrophy with acid production.
- increased TGF-a
What hormone causes gallbladder contraction? And which cell secretes it?
CCK from I cells.
Stress ulcers are caused by an increase in what?
pepsin production and gastric acid
Whats the most common location for Menckel’s diverticulum?
ileum
Which tumor markers are associated with pancreatic cancer?
CEA and CA19-9
Which organism is responsible for punched-out ulcers in the esophagus of IC pts?
HSV-1
What does serum alkaline phosphatase indicate?
Metastases to bone or liver, Paget disease of bone, seminoma
What drug is used to treat esophageal varices?
Octreotide (decreases portal blood flow)
which pressure changes cause pitting edema?
INC capillary pressure ( INC Pc; e.g., HF)
DEC plasma proteins ( DEC πc; e.g., nephrotic syndrome, liver failure)
INC capillary permeability ( INC Kf ; e.g., toxins, infections, burns)
INC interstitial fluid colloid osmotic pressure ( INC πi; e.g., lymphatic blockage)
Whats the MOA and indication for prochlorperazine?
Antiemetic that blocks dopamine receptors used for chemotherapy pts.
Where is a shunt created to help relieve portal HTN?
splenic vein (portal)-left renal vein (IVC)
What 3 factors stimulate gastric acid secretion in the parietal cells?
- histimine
- gastrin
- vagal stimulation
What is meconium ileus and what is the other disease it is associated with?
In cystic fibrosis, meconium plug obstructs intestine, preventing stool passage at birth.
What are normal levels of unconjugated and conjugated bilirubin in the portal vein?
unconjugated > conjugated
What part of the colon is denervated in Hirschprung’s disease?
Distal rectum always involved.
What clinical features would indicate enterovesicular fistula secondary to Crohn’s?
- ab pain
- brown-yellow urine (fecal contamination)
- multiple enteric orgs
Other than motility, what is the other function of migrating motility complexes?
Maintain low bacteria counts in the upper intestine
What is angiosarcoma?
Highly aggressive tumor that arises from blood vessels
What is a major risk factor for angiosarcoma?
Exposure to vinyl chloride
What characterizes carcinoid heart disease?
Right-sided endocardial fibrosis w tricuspid valve damage
Which apoprotein turns on lipoprotein lipase?
CII
Def in apoprotein CII causes what?
hyperlipidemia + high chylo levels
What is Zollinger-Ellison syndrome?
Gastrin-secreting tumor in the pancreas
Parietal cells provide which 2 excretory products?
- Intrinsic factor
2. Gastric acid
What 2 fetal abnormalities result in polyhydramnios?
- tracheoesophageal atresia
2. anencephaly
