GI Flashcards
Describe a Mallory body, where do you see it?
Intracytoplasmic eosinophilic inclusion; alcoholic hepatitis (AST>AST, make a toAST with alcohol)
Within which larger structure is the ligamentum teres hepatis contained? Fetal structure?
Falciform ligament; ligamentum teres hepatis was the umbilical vein
How is Puetz-Jehgers inherited?
AD; hyperpigmentation around mouth etc. with GI hamartomatous polyp
What disease causes a conjugated hyperbilirubinemia due to decreased excretion and has a black liver? Which is the same, though milder, and does not have a black liver?
Dubin-Johnson; Rotor syndrome
What is contained within the hepatoduodenal ligament?
portal triad (proper hepatic artery, common bile duct, portal vein)
T/F: primary sclerosing cholangitis is a granulomatous process
false, primary biliary cirrhosis is
Is the portion of the duodenum compressed in SMA syndrome intraperitoneal or extreaperitoneal?
Extraperitoneal (it is the 3rd part, and the 2nd and 3rd parts are retroperitoneal)
Explain the genetics of Familial Adenomatous Polyposis
AD mutation of 5q leads to a mutation of APC gene (then they just need a K-ras and p53)
What tumor marker is used for monitoring the recurrence of colorectal carcinoma?
CEA
What is a tortuous dilation of vessels causing hematochezia in old ppl?
angiodysplasia
Differentiate Type A and Type B chronic gastritis
Type A = Autoimmune; Type B = Bacterial, H. pylori? Type A affects the Body, Type B affects the Antrum (so it?s a goofy mnemonic)
ALT> AST
Viral hepatitis
When treating T. solium neurocysticercosis with praziquantel why should you also administer prednisone?
To prevent herniation once the cyst is killed
Where do the celiac trunk, SMA, and IMA branch off of the aorta (vertebral levels)? Where is the bifurcation of the aorta?
Celiac = T12, SMA = L1; IMA = L3; Bifurcation L4
Tx of Cryptosporidium? Tx of Cystoisospora
C. parvum = Nitazoxinide; C. belli = TMP-SMX
What is the major cause of death in Hirschsprung’s?
Bowel perforation
Which ligament separates the greater and lesser sacs and may be cut during surgery to access the lesser sac?
Gastrohepatic
Explain the DIRECT effects of atropine on parietal cells and G cells
Atropine blocks Ach release from vagus. Therefore, atropine inhibits parietal cell vagal stimulation ONLY? Vagus releases GRP on G cells and is therefore unaffected by atropine
Prostaglandins have an action on parietal cells most similar to what GI hormone?
Somatostatin? Both increase Gi to decrease cAMP and H
Discuss malignancy in Juvenille polyps
If single not malignant; if multiple = Juvenille polyposis syndrome = increased malignant potential
Tx of Criggler Najjar Type 1? Type II?
1) plasmapheresis and phototherapy (more severe) 2) phenobarbital because it increases liver enzymes
Which type of GI polyp has no potential for malignant transformation?
Hyperplastic polyps
Double bubble on xray
duodenal atresia, the constricting bit between the bubbles is the pylorus
How would you know that an increase in alkaline phosphatase was coming from the liver and not the bone?
Check GGT
What GI problem can mumps cause?
pancreatitis and parotitis, both would increase amylase
Which GI pathology is most associated with Trosseau’s syndrome?
pancreatic adenocarcinoma (CA-19-9)
Anti-mitochondrial antibodies are observed in _________
primary biliary cirrhosis
What is the primary area affected in celiac? What cancer is it associated with?
jejunum; T-Cell lymphoma
What infectious disease has elevated amylase?
mumps (parotitis)
What is the most common cause of small bowel obstruction
post-surgical adhesion
What 11 structures are retroperitoneal?
SAD PUCKER (Suprarenal gland, Aorta + IVC, 2nd and 3rd parts of duodenum, Pancreas (not tail), Ureters, Colon (ascending and descending), Kidneys, lower esophagus, lower rectum
Why would a patient with a tracheoesophageal fistula become cyanotic?
There is laryngospasm to avoid reflux-related aspiration
Which pancreatic bud gives rise to most of the pancreas?
Dorsal; however, the main pancreatic duct (and head and uncinate process) come from the ventral bud
The conjoined tendon arises from aponeuroses of which 2 muscles?
Transversus abdominis and internal oblique
What is the cause of an indirect hernia? Direct?
Failure of processus vaginalis to close; breakdown of transversalis fascia)
Cirrhosis, DM, and hyperpigmentation are associated with what gene mutation? What HLA?
Hemochromatosis = H63D or C282Y mutation on HFE gene; HLA-A3
What is the antecedent event of a pancreatic psuedocyst? What lines the inside of it giving it its name?
acute pancreatitis; granulation tissue instead of an epithelial lining
If indirect bilirubin is not water soluble how does it get to the liver?
Bound to albumin
What ligament contains the gastric arteries? Gastroepiploic arteries?
Gastric arteries = Gastrohepatic ligament; Gastroepiploic arteries = Gastrocolic ligament
Differentiate among the 3 major types of infectious esophagitis
CMV = linear ulcers; HSV-1 = punched out ulcers; Candida = cottage cheese, white pseudomembrane
Differentiate viral and alcoholic hepatitis based on aminotransferase levels
Alcoholic = AST > ALT; Viral = ALT>AST
What part of the stomach contains G cells?
antrum (secrete gastrin, phenylalanine and tryptophan are potent stimulators)
What is the mutation in HNPCC?
DNA mismatch repair genes (lynch syndrome) autosomal dominant
How are the zones of the hepatocytes named?
Zone 1 is closest to the portal triad, Zone 3 is closest to the central vein
What type of esophageal cancer is celiac sprue associated with?
SCC
What is the rate-limiting step in carbohydrate uptake by intestine, explain.
Oligosaccharide hydrolase activity (dissacharidases, etc.) because only monosaccharides can be taken up by enterocytes? Amylase breaks things down primarily to disaccharides
What is conjugated to bile acids to make them soluble? What is conjugated to bilirubin to make it soluble?
Bile acids made to bile salts with glycine or taurine, bilirubin gets glucuronate added by UDP glucuronyltransferase
Which hereditary colon cancers are associated with A) the microsatellite instability pathway B) the APC/B-catenin pathway?
A) HNPCC, microsatellite instability affects mismatch repair enzymes; B = FAP, AD mutations in chromosome 5q for APC
How does hepatocellular carcinoma usually spread?
hematogenously
What disease may be associated with painless cholecystitis?
Diabetes due to autonomic neuropathy; same deal with atypical or even silent myocardial infarctions
Which FAP subtype has a congenital hypertrophy of the retinal pigment epithelium?
Gardner’s syndrome? Autosomal dominant; also osteomas of jaw
What GI disease are Native American indians susceptible to?
CHOLESTEROL gallstones (decreased 7 alpha-hydroxylase)
Where are false diverticulae most likely to form?
Where the vasa rectae penetrate the muscularis externa
What is the theorized cause of Crohn’s? UC?
Crohn’s = disorganized response to bacteria; UC = autoimmune
Which cells produce pepsin?
Chief cells
Conjugated bilirubin is converted to urobilinogen by bacteria in the gut? What form is excreted in in feces? In urine?
Urobilinogen to stercobilin in feces; urobilinogen to urobilin in urine
Sclerosis around central vein of liver
cirrhosis; zone III (centrilobular) has CYP 450 system and is most susceptible to toxins (i.e. acetylaldehyde)
In the leg, the mnemonic NAVL is in what direction?
lateral to medial (nerve, artery, veins, lymphatics)? Remember, you go from lateral to medial to find your NAVEL!
What is the most common malignant tumor of salivary glands?
Mucoepidermoid carcinoma
Which malabsorption syndrome results in a decreased ability to transport dietary lipids and endogenous lipids?
Abetalipoproteinemia? Dietary lipids = chylomicrons B48. Endogenous lipids = VLDL, B100?. B48 and B100 are same gene but alternate splicing
What parts of the duodenum are retroperitoneal?
2nd and 3rd parts
Which histologic liver zone is affected first by ischemia?
Zone 3? Recall that zone 1 is closest to the portal triad and zone 3 is closest to the central vein; therefore, zone 3 is most distal = most susceptible to ischemia
Why does Budd-Chiari and right heart failure cause centrilobular congestion and necrosis?
The central vein (which will contribute to the hepatic vein) is at the center of the lobule (zone III)? Thus when the IVC/hepatic veins are obstructed or backed up, this will have the most congestion
Although the most important mechanism for gastrin to increase H ion is through the ECL cells producing histamine, what receptor does gastrin bind to directly on parietal cells?
CCK type B
Which salivary gland tumor has germinal centers?
Warthins tumor (benign)
What cause of hepatocellular carcinoma is inherited in a codominant fashion?
A1AT deficiency
A GI malignancy with dense core bodies on EM is _______
Carcinoid syndrome
What is the cause of a patient with watery diarrhea, hypokalemia and a high gastric pH? Tx
VIPoma this is WDHA syndrome (Watery Diarrhea, Hypokalemia, Achlorhydria); Tx: octreotide
What kind of cancer is H. pylori associated with?
MALT lymphoma
What are the main causes of hepatic adenomas?
OCPs (House episode), and Steroids?. Note that this is benign
What parts of the colon are retroperitoneal?
Ascending and descending
Cause of black and brown pigment gallstones
black = hemolysis; brown = infection
Antibodies to c-Kit identify what type of GI cancer? What cell is it from?
GIST (Gastrointestinal stomal tumor); interstitial cells of Cajal
What blood type is associated with intestinal type stomach cancer? What environmental toxin?
Type A blood, Nitrosamines (smoked fish)? The most common cause of intestinal type is H. pylori
This is a fusiform and filamentous gram negative rod that has gliding motility like proteus, and it is normal flora of the mouth
Capnocytophaga spp.
Where does the uncinate process of the pancreas come from?
The ventral pancreatic bud only
What GI problem might a scorpion sting cause?
Acute pancreatitis
Which small intestine region has the most goblet cells?
ileum
Where are iron and folate absorbed? B12?
Fe = duodenum; Folate = Jejunum; B12 ileum
What is the worldwide most common cause of esophageal varices?
Schistosomiasis (S. mansoni, causes clay pipestem fibrosis of the portal vein = portal HTN = varices)
The inferior rectal artery supplies tissue below the pectinate line and is a branch of _________
internal pudendal artery
AST > ALT
alcoholic hepatitis
Diaphragmatic hernias may arise from inadequate development of what?
Pleuroperitoneal membrane (hiatal hernia–through esophageal hiatus, sliding hiatal hernia, paraesophageal hernia)
What is a hereditary disorder involving mutations in mismatch repair genes that always affects the proximal colon?
Hereditary Non-Polyposis colorectal carcinoma (HNPCC) aka Lynch Syndrome (AD genetics)
How do you diagnose Hirschsprung’s?
rectal suction biopsy
What side of the hepatocyte is the issue in Wilson’s Dz? What is the tx?
apical surface since that faces the bile canaliculus; penicillamine
Which FAP subtype is associated with CNS malignancy?
Turcot (also autosomal dominant)
What are the 3 steps in the APC/B-catenin process of colon cancer?
AK-53? Loss of APC = decreased intercellular adhesion (loss of catenin); K-ras = unregulated signal transduction; p-53 = tumorigenesis
Why is zone 3 of the liver acinus most susceptible to toxic injury?
It contains the CYP 450 system and therefore has the highest concentration of toxic metabolites
What gene and chromosome are affected in Wilson’s? Inheritance pattern?
ATP7B (Cu transporting ATPase) and chromosome 13; AR
Sternal defects such as ectopia cordis result when which body folds don?t form properly?
Rostral fold; Lateral fold = abdominal; Caudal fold = pelvic, i.e. exstrophy
Addition of what (2) makes a bile acid a bile salt?
adding glycine or taurine
What dermatologic manifestation may stomach cancer have?
acanthosis nigricans
What aspect of the vagus nerve, with respect to the GI system, is not affected by administration of atropine?
Only the release of Ach is affected? GRP is also secreted by it onto G cells as well as NO onto LES muscles, these functions would not be affected
Are you more likely to find H. pylori in stomach ulcers or duodenal ulcers?
They are in 100% of duodenal ulcers but only 70% of stomach ulcers
What surfaces of a hepatocyte face the bile canaliculus and which faces the sinusoids?
Apical surface is to bile canaliculus (think that apical surfaces usually secrete), Basolateral surface faces the sinusoids
What virus may cause intussusception?
adenovirus
What pathology has a herniation of mucosal tissue at Killian’s triangle?
Zenker diverticulum; herniates between thryopharyngeal and cricopharyngeal aspects of inferior pharyngeal constrictor
Barrel shaped egg with plugged ends? Complication?
Trichuris trichuria (whipworm); rectal prolapse
What layers cover an indirect inguinal hernia? Direct?
Indirect covered by all layers that cover spermatic cord because it follows descent of testes = external spermatic fascia, cremesteric fascia, internal spermatic fascia; Direct covered only by external spermatic fascia
How does gastrin increase H secretion?
Indirectly by stimulating ECL cells (enterochromaffin like), these then release histamine which stimulates gastric acid secretion
What is a risk factor (aside from familial) for both SCC and adenocarcinoma of the esophagus?
Cigarettes
Explain the oddity that is splenic embryological development?
The spleen is not a foregut derivative (endoderm) like most things supplied by the celiac? Rather it is from the mesentery of the stomach and is therefore a mesodermal derivative
Parkinsonian Sx with asterixis is highly suspect of?
Wilson’s disease (Parkinsonian Sx from Cu in basal ganglia; Asterixis from cirrhosis/hepatocellular carcinoma)
What are the 3 major salivary gland tumors? Which is most likely to recur?
Pleomorphic adenoma (most likely to recur), Warthin’s tumor (has germinal centers, benign), Mucoepidermoid carcinoma (malignant, invades facial nerve)
What histological subtype of an adenomatous GI polyp is most likely to be malignant?
villous histology
What part of the pancreas is not retroperitoneal?
tail
Which biliary tract disease is BEST characterized as being autoimmune?
primary biliary cirrhosis; primary sclerosing cholangitis has an unknown etiology
Where will you bleed from a ruptured lesser curvature ulcer? Posterior wall ulcer?
lesser curvature = left gastric a; posterior wall = gastroduodenal a
Which histologic liver zone is affected first by viral hepatitis?
zone 1
Which structure in the femoral triangle is not present in the femoral sheath?
The femoral nerve
What is a cause of infectious cholecystitis?
CMV
If an ulcer is associated with weight loss where is it most likely to be located? Why?
Stomach because stomach ulcers get worse with eating, duodenal ulcers get better so they are associated with weight gain
What is a HIDA scan? What is it used to diagnose?
Radionuclide biliary scan, for cholelithiasis
What is Courvoisier’s sign?
a palpable nontender gallbladder from pancreatic adenocarcinoma causing an obstructive jaundice
Which is malabsorption more of an issue, UC or Crohn’s?
Crohn’s because it affects the small intestine
What has a higher risk of carcinoma, gastric or duodenal ulcers?
gastric? just remember that aside from carcinoid, small intestine CA is very rare
What inherited hepatobiliary disease responds to phenobarbital?
Crigler Najjar type II; phenobarbital increase liver enzyme synthesis
Which ducts are affected in PBC and PSC?
PBC is intrahepatic involvement; PSC is intra and extrahepatic involvement
Which zone of the liver acinus contains the CYP 450 system?
Zone 3
What is the initial syndrome of all flukes?
Katayama syndrome (itchiness)
What cells produce Glucose-dependent Insulinotropic Peptide? In addition to its role as an incretin, what else does it do?
K cells in duodenum and jejunum; it is also called GIP or gastric inhibitory peptide so it decreases H production
What is the function of the D-xylose absorption test?
distinguish GI mucosal damage from other causes of malabsorption
When does the midgut herniate? Return back to the inside?
Week 6, Week 10
What hernia type is the leading cause of bowel incarceration?
Femoral hernia
What genetic disease predisposes to SCC of the esophagus?
Tylosis
What pertinent negative differentiates Budd-Chiari from right heart failure?
No JVD in BC
What is the pringle maneuver?
Surgical technique in which the hepatoduodenal ligament (containing the portal triad) is compressed with fingers to control bleeding
Name a ciliated protozoan that causes bloody diarrhea
Balantidium coli (found in pigs)? Tx = tetracycline
What are the 2 etiologies of Gilbert’s?
1) Decreased UDP glucuronyltransferase activity 2) decreased uptake of unconjugated bilirubin by hepatocytes
Knobby coated oval shaped, bile staining eggs
Ascaris lumbricoides
Where will you find the splenic artery (what ligament)?
Splenorenal
Which type of hernia is the most common in women?
Femoral hernia
Tx of hereditary hemochromatosis? (3)
phlebotomy (wouldn?t work in secondary since that is from transfusions for B thalassemia major), deferasirox, deferoxamine
What do the I cells produce?
CCK (levels are increased by FA and AA’s)
Gram stain of Trophyrema whipplei?
Gram positive (PAS positive macrophages)
What GI drug can be used to Tx ETEC?
Bismuth and Sucralfate
Tumor marker for hepatocellular carcinoma
alpha fetoprotein (also in endodermal sinus tumor)
Hobnail liver
cirrhosis
Which liver zone is also known as the centrilobular zone?
Zone 3 (pericentral = centrilobular? So the nomenclature is such that the central vein is the center of the lobule i.e. centrilobular)
What is the term for gas present within the walls of the intestine?
Pneumatosis intestinalis
When will you see Brunner gland hypertrophy?
Peptic Ulcer Disease
Which cell mediates the villous atrophy of celiac sprue?
CD8? The HLA involved is HLA-DQ2/8
How do you confirm a diagnosis of angiodysplasia?
angiography
What cell type mediates non-caseating granulomas in Crohn’s? What cell mediates crypt abscesses in UC?
Th1; Th2
What is the most common cause of appendicitis in adults? Kids?
Obstructing fecalith; lymphoid hyperplasia
What 3 arteries ultimately contribute the most blood to the stomach?
Left gastric, Common hepatic, and Splenic
2 markers for pancreatic adenocarcinoma
CA-19-9 and CEA although CEA is less specific
The rate-limiting step for converting cholesterol into bile acids is done by __________
7 alpha hydroxylase
Discuss the tonicity of saliva as a function of flow rate
At normal resting flow rates it is hypotonic due to excessive absorption of ions back into the ductal cells? At higher flow rates it is isotonic.
Tx of physiologic neonatal jaundice
phototherapy
