Flashcards in GI Deck (173):
Disease producing asymptomatic unconj bilirubinemia
Child vomited a large, long cylindrical white worm, what's its route of infection?
Ingestion of eggs from human feces
What would be seen in mucosa bx of gastric in Menetrier disease
Mucous cell hyperplasia -> losing protein
Meningitis, see lymphocytes, plasma cells, macrophages, fibroblasts in CSF with elevated protein and depressed glucose. Emigrated from Ecuador. What infection?
What 2 orgs cause HIV-assc esophagitis w/ ulcers?
CMV (linear ulcers)
HSV-1 (punched out ulcers)
Fever, confusion, nausea, elevated LFTs and bilirubin 4 days after laparotomy. What will be seen on liver bx?
Massive hepatic necrosis
Most likely from the use of halothane as anesthetics
Kid w/ bilious vomiting and cecum fixed to RU abd wall. What's the problem?
Failure of midgut to rotate around SMA
2 day old w/ bilious vomiting. No large segment of small bowel but see distal ileum winding around a thin vascular stalk. What's the intrauterine process affected?
Vascular occlusion (responsible for apple peel atresia, which is predominant when atresia happens distal to 2nd segment of duodenum. Before that segment, it's failure to recanalize)
Pt w/ pruritus, rash, flushing, abd cramps, and nests of mast cells in mucosa. What do you expect to see in stomach?
This is systemic mastocytosis, and all the histamine secretions by mast cells will result in acid secretion
What structure receives blood supply from the foregut even though it's not a foregut derivative?
Spleen (mesodermal origin)
Another term for ectopy?
Bx of eyelid shows cells with clear droplets in them. What are the disease associations?
That's xanthelasma -> lipid accumulates in macrophages (foam cells)
It's assc. w/ primary or secondary hyperlipidemia, so things like PBC and obstructive biliary lesions can cause this
What do you need a life-long supplement of after total gastrectomy?
B12 ("water soluble vitamin") bc no longer making IF -> give B12 parenterally
How does HBV increase the risk of HCC?
Integration into genome (DNA virus) -> continues to produce HBx protein even after infection clears -> disrupts cell cycle control by activating multiple growth-promoting proteins and inactivating p53
3 characteristics histological findings of GERD
Lamina propria papillae elongation
Basal zone hyperplasia
Inflammatory cells (lymphocytes, eosinophils, neutrophils)
Disease associations of imperforate anus
Most common: GU anomalies -> fistulas (urorectal, urovesical, urovaginal), renal agenesis, hypospadias, dpispadias, bladder extrophy
Less common: VACTERL -> Vetebral defects, Anal atresia, Cardiac anomalies, TE fistula, Esophageal atresia, Renal anomalies, Limb anomalies
Distended macrophages in the intestinal lamina propria. What's the disease? What does macrophage contain?
Macrophages contain PAS-positive and diastase-resistant granules and rod-shaped bac
Neutrophils w/in crypt lumina (intestine). What's the disease?
Inflammation w/ scattered noncaseating granulomas (intestine). What's the disease?
Massive infiltration of lamina propria w/ atypical lymphocytes. What's the disease?
Jaundice + dyspnea w/ hyperlucency lung fields and flattened diaphragm in nonsmoker. Hx of neonatal hepatitis. What's the disease?
What's a Courvoisier sign?
Palpable but nontender bladder
See this sign in adenocarcinoma at the head of pancreas compressing common bile duct
Palpable but nontender gallbladder + weight loss + dark urine + pale stools
Adenocarcinoma at the head of pancreas compressing common bile duct
Palpable but nontender gallbladder = Courvoisier sign
Dark urine + pale stool + pruritis = obstructive jaundice
5 risk factors for pancreatic cancer
Smoking!!! -> most important
Age > 50
Genetics: hereditary pancreatitis, MEN, HNPCC, FAP
Moderate alcohol use in the absence of chronic pancreatitis doesn't confer risk
Pancreatic juice ion conc w/ respect to plasma?
Isotonic secretion overall
Same conc of Na+, K+ as plasma
Higher HCO3- than plasma
Lower Cl- than plasma
Cl- decreases in proportion to HCO3- increase (this is opposite of sweat glands, which secrete more Cl- compared to HCO3-)
What kind of diarrhea do you see in Crohn and carcinoid syndrome? What is the characteristics of that type of diarrhea?
High electrolyte content from poor absorption and increased losses from inflamed mucosa
What's an important cause of rectal prolapse in children?
Dx for severe upper abd pain + vomiting + fever w/ necrotic gallbladder? Give 5 steps of pathogenesis.
Acute calculous cholecystitis
Steps: gallbladder outflow obstruction (cholelithiasis) -> protective mucus layer disrupted by stones, so epithelium exposed to detergent action of bile salts -> PGs released and further aggravate inflammation -> gallbladder hypomotility -> ischemia from distention and internal pressure -> bacteria invasion of necrotic tissue
What is "ramified, tubular glands in submucosa w/ pH secretions close to 9.0"
Brunner's glands -> unique to duodenum
Pathogenesis of hepatic encephalopathy?
Increased inhibitory neurotransmission (GABA) and impaired excitatory neurotransmission (glutamate and catecholamines)
NH4+ increases activity of of 2 enzymes:
1. glutamine synthetase w/in astrocytes -> converting glutamate released from neurons to glutamine, which accumulates and causes hyperosmality and mitochondrial dysfx -> astrocyte dysfx
2. glutamate DH w/in neurons -> depletes alpha-glutamate in an attempt to detoxify
Might also have elevated oxindole during this condition -> tryptophan derivative formed by bacteria in the gut and is normally cleared by liver -> oxindole causes sedation, muscle weakness, hypotension, and coma
Finely eosinophilic granules in cytoplasm + portal inflammation + hepatocyte ballooning + necrosis
Eosinophilic granules are aggregates of HBsAg -> "ground glass"
Lymphoid aggregates w/in portal tracts + focal areas of macrovesicular steatosis
Confirmatory test in Dubin-Johnson? Why is liver black?
High coproporphyrin I in urine
Liver is black from dense pigment composed of epinephrine metabolites w/in lysosomes
What condition do you see smooth muscle cell Ab?
Steps of acute pancreatitis?
Damage to pancreatic acinar cells (direct insult or ischemia) -> activation of TRYPSIN inside acinar cells by lysosomal enzyme (MAIN EVENT) -> autodigestion (fat necrosis by lipase and everything else comes later)
In severe cases get acute necrotizing pancreatitis -> see diffuse enlargement w/ area of necrosis)
What do you see in liver bx in Reye syndrome? Brain? How about labs?
Liver bx: microvesicular steatosis WITHOUT inflammation; EM see decreased mito and glycogen depletion
Brain: cerebral edema
Labs: prolonged PT/PTT, high ammonia, bilirubin, AST, ALT
5 ways to inactivate hep A?
Boiling 85C for 1 min
Bleach (1:100 dilution)
What is D-xylose?
Monosaccharide that can be absorbed directly w/out the action of pancreatic enzyme
So it's used to distinguish malabsorption of pancreatic from GI mucosa defects
Common sx of PBC? Histologic features?
Pruritus (first sx!), xanthelasma, pale stool
Florid duct lesion: interlobular bile duct destruction by granulomatous inflammation & lymphocyte-predominant portal tract infiltrate -> so features similar to GVHD
End-stage findings can't be distinguished from secondary biliary cirrhosis or chronic hepatitis
Prolonged pruritus + fatigue is also assc. w/ PSC
"green-brown plugs in dilated bile canaliculi, yellowish-green deposition w/in hepatic parenchyma" describes?
Cholestasis in general (can be obstructive or nonobstructive) -> so find the etiology
What does prolonged cholestasis predispose you to?
Fat malabsorption -> so think about conditions resulting from fat-sol vitamins deficiency (for example, osteomalacia from vit D deficiency)
Pain w/ hip extension (causes psoas major to be stretched out)
Psoas major inserts on lesser trochanter of femur via tendon shared w/ iliacus m. -> they both are major flexor of hip
Another name for pancreatic cholera or WDHA syndrome?
VIPoma (pancreatic non-beta islet cell tumor) -> VIP also secreted by neurons in GI mucosa
WDHA = Watery Diarrhea, Hypokalemia, Achlorhydia (b/c VIP inhibits gastric H+ secretion)
Fixed w/ somatostatin
2 complications of glucagonoma?
Necrolytic migratory erythema of skin
Example of pulsion diverticulum? Traction diverticulum?
Pulsion (false diverticula): colonic diverticula
Traction (true diverticula due to inflammation and subsequent scarring): midesophageal diverticula (from mediastinal lymphadenitis like TB and fungal infections, and periesophageal scarring)
Sx of carcinoid syndrome? What's the cardiac finding? Do you get hypertension or hypotension?
Facial flushing, bronchospasm, diarrhea
Cardiac finding: fibrous intimal thickening w/ endocardial plaques limited to right heart -> eventually get pulmonic stenosis and restrictive cardiomyopathy
Marker of HBV that's worrisome for vertical transmission?
HBeAg -> viral replication and increased infectivity
So if mom is infected w/ HBV, always give newborn passive immunization w/ HBIG, followed by active immunization w/ recombinan HBV vaccine
What does anti-HBc IgM signify?
Window period (HBsAg has cleared but anti-HBs has not yet appeared) -> most specific marker for dx of acute hep B
What does HBsAg signify?
But NOT the most worrisome marker in pregnant women, HBeAg is
What molecule is present after either successful vaccination against HBV or clearance of HBV?
Anti-HBsAg IgG -> indicator of noninfectivity and immunity
What are ppl on TPN (total parenteral nutrition) susceptible to and why?
B/c there's no stimulation of CCK release -> so now bile duct movement -> biliary stasis
If this involves ileal resection, condition is further made worse by the fact that bile acid circulation is disturbed -> supersaturation of hepatic bile w/ cholesterol
What 3 Ab do you find in ppl w/ celiac disease?
Are spleen, pancreas, and adrenal glands retroperitoneal?
Spleen = intraperitoneal -> injury creates hemoperitoneum
Pancreas = retroperitoneal except tail (intraperitoneal) -> so if car collision w/ retroperitoneal hematoma -> choose trauma to pancreas
Adrenal glands = retroperitoneal
What does secretin do besides stimulating HCO3- release and inhibiting H+ release?
Stimulates pyloric sphincter contraction
(so pancreas can start secreting juice to digest stuff in intestine)
1st step in screening for malabsorption?
Sudan III stool stain -> quantify fat content
Labs to check if wanna know about liver/bile duct damage? Labs to check if wanna know about prognosis?
Liver damage markers: AST, ALT, Alk Phos, GGT (differentiate bet. biliary from other causes when alk phos is elevated)
PROGNOSIS MARKER: PT time (elevated first b/c factor VII has the shortest HL), serum albumin, bilirubin
2 histologic presentations of acute viral hepatitis?
Hepatocyte INJURY: ballooning degeneration
Hepatocyte DEATH: bridging necrosis, mononuclear inflammation -> might present w/ fever and dark urine (from increased serum bilirubin)
Acute portal HTN w/ normal liver bx. What's the cause?
Portal vein thrombosis (key is normal liver bx -> indicates that presinusoidal process is responsible)
Ascites is UNCOMMON b/c don't normally develop sinusoidal HTN -> will just get esophageal varices
What do you see on liver bx in Budd Chiari?
Centrilobular congestion ("dilation of sinusoids + perivenular hemorrhage" esp w/ acute obstruction) and fibrosis
What's a lymphoid polyp?
Intestinal mucosa infiltrated w/ lymphocytes
Benign, common in children
Where is portal vein in relation to IVC and liver on X-section scan?
Ant. to IVC
Medial/just within right lobe of liver
What do you see on barium swallow in DES (diffuse esophageal spasm)? What are prestening sx?
"corkscrew" esophagus from periodic, non-peristaltic esophageal muscle contraction
Present w/ dysphagia and chest pain
What creates an umbilical hernia?
Weakness in the abdominal wall around umbilicus -> covered by skin and usually closes spontaneously by 2 yo
What's the main defect in Zenker diverticulum?
Cricopharyngeal muscle dysfx (from diminished relaxation of pharyngeal muscles during swallowing) -> pulsion diverticulum (false) -> might be able to palpate as lateral neck mass
What's the pathogenesis in achalasia?
Degenerative changes in MYENTERIC PLEXUS
Gastric ulcers vs. erosions?
Erosions: don't extend thru muscularis mucosa (so limited to mucosal layer) -> but acute erosive gastropathy can cause upper GI bleed that leads to melena
Ulcers: extend into submucosal layer
Why can't you generate protective immune responses against HCV?
ENVELOPE GLYCOPROTEIN that's prone to frequent mutation
No proofreading 3'->5' exonuclease activity
Locations of carcinoid tumor? What's the cell of origin?
Ileum, appendix, rectum -> these gotta met to liver to produce sx
If bronchial or extraintestinal -> produce sx w/out having to metastasize first
Enterochromaffin cells of intestine mucosa
Where is the majority of painful anal fissures? What might you find on PE w/ chronic anal fissures?
Single post. midline of anal verge distal to dentate line -> poorly perfused area
Might see anal skin tag w/ chronic fissure
What kind of filaments makes up microvilli?
Air in gallbladder and biliary tree. Where's the gallstone?
Ileum at ileocecal valve
This is from gallstone ileus -> get cholecystenteric fistula bet. gallbladder and adjoining gut tissue -> gallstone passed to small intestine and gets all the way thru to ileocecal valve and gets trapped there
Won't have air in gallbladder/biliary tree if stone is just in cystic duct or common bile duct ("choledocolithiasis")
What kind of channel does PPI inhibit?
H+/K+ ATPase -> so primary active transport! (unlike other drugs that affect voltage-gated ion transports, which are usually passive)
What molecule do you use to screen for carcinoid tumors?
5-hydroxyindoleacetic acid (breakdown product of serotonin)
What encodes heat labile (LT) and heat stable (ST) enterotoxins by ETEC (enterotoxigenic E. coli)?
What org causes "stacked-brick" intestinal adhesion?
EAEC (enteroaggressive E. coli) -> don't invade, implicated in persistent diarrhea in infants in developing countries
What does hep D virus need HBV for?
Coating -> needs HBsAg to coat its viral particles (circular ss RNA molecules)
2 phases of HBV infection?
Proliferative phase: HBsAg and HBcAg bound to MHC I on host cell surface -> activates CD8+ T cells which destroy infected hepatocytes (MAIN MECHANISM OF LIVER INJURY)
Integrative phase: infectivity ceases and liver damage tapers off when Abs appear, risk of HCC remains elevated
Host's Abs only have a role in neutralizing ABV infectivity BEFORE virus enter hepatocytes (so Ab not assc. w/ hepatocellular damage)
Layers of stomach from top to muscularis mucosae and the cell composition
Top = simple columnar epithelium -> mucus
Upper glandular layer = parietal cells (oxyntic/pink, round, plate-like)
Deeper aspect of gastric glands = chief cells (small, basophilic, granular)
What do each of 3 HBV Ags do?
HBcAg = nucleocapsid core protein -> stays in hepatocytes and assembles virion
HBeAg = nucleocapsid core (stays in hepatocytes and assembles virion) and precore protein (directs secretion into blood)
HBsAg = noninfective envelope glycoprotein that forms spheres and tubules 22nm in diameter -> hepatocytes secrete a lot of this (out of proportion to amont of HBcAg produced -> so it's a "product of viral synthesis that poorly correlates w/ viral replication")
What kind of grains contain gluten?
Wheat, rye, barley contain gluten
Oats and rice don't
Why do you get pancytopenia in chronic liver disease/cirrhosis?
What is Cooper's ligament and where is it?
Cooper's ligament = pectineal ligament = thickened part of pectineal fascia
Overlies pectineal ridge of pubic bone, posterior to femoral canal
What is transversalis fascia in relation to inguinal canal?
It forms posterior wall of inguinal canal
Deep inguinal ring is an opening in transversalis fascia
Liver bx in extrahepatic biliary atresia? When does it present w/ total obstruction?
Bx: intrahepatic bile ductule proliferation, portal tract edema and fibrosis, parenchymal cholestasis
Obstruction by 3rd week of life -> biliary cirrhosis by 6 months of life
What distinguishes pancreatic pseudocysts from true cysts?
Pseudocysts are lined by granulation tissue and no epithelial lining -> gets fibrosis and thickening over time
What kind of pancreatic neoplasm do you see glycogen-rich cuboidal epithelium in?
Serous pancreatic neoplasms (as opposed to mucinous cystic kind which is lined by columnar mucinous epithelium)
When is pica most common and what's the usual thing ppl eat?
Common in pregnancy
Ice is the most common ingested substance
2 ways to get hereditary pancreatitis?
1. SPINK1 gene mutated (secreted by pancreatic acinar to fx as trypsin inhibitor)
2. production of abnormal trypin that's not susceptible to inactivating cleavage by other trypsin
4 parts of duodenum and their structural relations?
1st part (horizontal): only one not retroperitoneal
2nd part (vertical): head of pancreas
3rd part (horizontal): SMA (right in front of it), pancreas uncinate process
4th part (vertical): ends at ligament of Treitz
How is urease breath test performed?
Pt consumes C-13 labeled urea and then monitor BREATH for precence of that C-13
For H pylori testing
Who is at high risk of getting trypanosoma cruzi and how does it manifest?
Central & S. America
Neurotoxin destroys myenteric plexi in eso (get 2ndary achalasia), intestines (megacolon), ureters (megaureter)
Dx of "intrahepatic hydatid cysts w/ surrounding fibrous rxn"?
Pancreatic finding in CF?
Exocrine gland fibrotic atrophy
What structures could be bleeding if using Pringle maneuver doesn't stop the bleeding?
Pringle maneuver = occludes portal triad
So think about IV or hepatic veins if this doesn't stop the bleeding
In neonate whose mother is + for HBeAg, what are the risk of chronic infection, viral replication rate, and level of liver enzymes?
Risk of chronic infection: high
Viral replication rate: high
Level of liver enzymes: mildly elevated
What causes direct hernia?
Breakdown of transversalis fascia
Diff bet. coverings of direct and indirect hernias?
Indirect hernia: covered by all 3 spermatic fascial layers
Direct hernia: covered only by external spermatic fascia
Cephalic vs. gastric vs. intestinal phases?
Cephalic: cholinergic mediates
Gastric: gastrin mediates
Intestinal: ileum & colon releases peptide YY -> binds ECL to inhibits gastrin-stimulated histamine release -> so effectively downregulates gastric secretion
What is anti-HAV IgM a marker of?
What's another name for migratory thrombophlebitis? And what conditions is this assc. w/?
Trousseau's syndrome: adenocarcinomas produce thromboplastin-like substance that causes chronic intravascular coagulation
Assc. w/ adenocarcinomas of pancreas, colon, lung
What is hemorrhagic diathesis assc. w/?
Celiac sprue (malabsorption of vit K)
What should you do when you discover porcelain gallbladders?
Cholecystectomy -> risk of gallbladder carcinoma even if asymptomatic!
How does glucagonoma present?
DM, normocytic normochromic anemia
Necrolytic migratory erythema (raised rash typically affecting groin area) -> coalesce to form large lesion w/ CENTRAL CLEARING of BRONZE-colored induration -> can also affect mucus membrane so might see glossitis, cheilitis, blephritis
Diarrheal drugs affecting motility? Absorption? Secretion?
Motility: diphenoxylate (opiate that slows motility -> combined w/ atropine to get adverse sx at higher dose -> discourage abuse)
Absorption: kaolin-pectin, attapulgite (adsorb things to make stools less watery)
Secretion: bismuth subsalicylate, probiotics, octreotide
How does hepatic adenoma usually present?
Sudden collapse from rupture and intraabdominal bleeding; or just RUQ pain
Seen in women on long-term OCP
Don't see AFP elevation like HCC
What colon tumor manifests as secretory diarrhea (diarrhea containing a lot of mucoid material) and hypokalemia?
Diff in presentation of left sided colon cancers and right sided? What about rectal?
Left sided: obstruction + abd pain, distention, n/v
Right sided: iron deficiency anemia, anorexia, malaise, weight loss
Rectal: tenesmus and thin stool
"moldy" grains that cause specific G-to-T mutation in p53. What's the cancer risk?
It's referring to aflatoxin -> produced by Aspergillus and grows on food like corn, soybean, peanuts
How does H. pylori lead to duodenal ulceration?
H. pylori infection -> decreased in delta cells (produce somatostatin) -> increased H+ secretion by parietal cells -> gastric fluid w/ very low pH that's not adequately neutralized by duodenal bicarb production -> duodenal ulcers and duodenal gastric metaplasia
What deficiencies should you worry about w/ gastrojejunostomy?
Iron (absorption in duodenum and proximal jejunum)
Fat-sol vitamines (esp vit D)
Where is vit C absorbed?
Distal small bowel thru active transport process
Where is B6 absorbed?
Jejunum and ileum by passive diffusion
Where are B7 and B5 absorbed?
Small and large intestine via Na+-dependent multivitamin transporter
What organs does whipple disease involved besides bowel?
Joint: arthropathy, polyarthritis
Psychiatric and cardiac abnormalities
What kind of pts is parenteral nutrition appropriate for?
Pts in need of prolonged bowel rest -> like those suffering from acute pancreatitis
What is cavernous hemangioma and what does it look like under the scope?
Most common benign liver tumor -> congenital malformations that enlarge by ectasia, NOT hyperplasia or hypertrophy
See well-circumscribed masses of spongy consistency, blood-filled vascular spaces lined by single epithelial layer -> can surgically remove, but DONT bx (fatal hemorrhage)
What is ulcerative anal mass assc. w/?
SCC assc. w/ HPV 16 and 18 -> immunocompromised state (HIV) makes it more likely, esp if homosexuals
Hard mass obstructing ileocecal valve w/ cholesterol content of 85%. What is this?
What does coffee ground emesis mean?
Blood exposed to gastric acid & oxidation of heme iron -> sign of upper GI bleed
How does opioid lead to severe RUQ pain?
Opioid stimulates SMC in sphincter of Oddi -> constriction and spasm -> biliary colic
So use NSAIDs for pain control instead if this happens
How does opioid cause constipation?
By binding to mu receptors on gut ENTEROCYTES -> slowing motility
What is acute acalculous cholescystitis and when should you suspect it? What are the complications?
Acute inflammation of gallbladder in absence of gallstones
Suspect in hospitalized pts who are very ill & complain of RUQ pain and fever. Jaundice + palpable RUQ mass might be present (won't see this in acute calculouus cholecystitis)
Complications: gangrene, perforation, emphysematous cholecystitis
What is choledochal cyst?
Congenital dilations of common bile duct
Diff bet. 2 kinds of pigment gallstones?
Black: 2ndary to intravascular hemolysis
Brown: 2ndary to biliary infection like fluke infection
What does 99mmTc-pertechnetate scan detect?
What happens in failure of proper hindgut descent
Diff degrees of anal agenesis or imperforate anus
How do you dx intussusception?
PE (might feel tubular mass in RLQ) & barium enema (might be therapeutic too)
What kind of virus is HEV?
Naked, ss RNA
What artery supplies pylorus?
Gastroduodenal (also gives rise to right gastroepiploic)
What is right gastric artery a branch of?
Proper hepatic artery
Veins draining rectum?
Sup. rectal veins -> portal circulation
Middle rectal veins -> int. iliac -> systemic circulation
Inf. rectal veins -> int. pudendal -> systemic circulation
What are Councilman bodies?
Apoptotic hepatocyte bodies - round acidophilic -> see this in anything that kill hepatocytes like acute viral hepatitis
What does cryptosporidiosis look like? How does it present?
Endoscopy shows inflammation w/ NO ulcers -> bx shows basophilic clusters on surface of intestinal mucosal cells
Profuse, watery diarrhea in pts w/ advanced AIDS (CD4+ < 180)
Flask-shaped colonic ulcers?
Entamoeba histolytica (might see trophozoites w/ phagocytosed RBCs)
How is colorectal carcinoma that is colitis-assc. different from sporadic one?
More likely to arise from flat/non-polypoid dysplasia, have signet ring morphology or be mucinous, be multifocal, and develop early p53 mutations and late APC mutations (opposite sequence of sporadic form)
Signs suggestive of chronic mesenteric ischemia? Most often cause?
Signs: epigastric/periumbilical pain that occurs 30-60 min after food intake -> pain severe enough (even tho PE normal) that pts avoid eating and lose weight
Don't confuse w/ gallbladder pain!
Most often cause is atherosclerosis of celiac, SMA, IMA
Most common causes of acute pancreatitis?
Gallstones and alcoholism
But if rule those out and no obv things going on (like post-surgery, hypercalcemia, infection, etc), consider hyperTG -> over 1000 mg/dL is directly toxic to tissue and will cause acute pancreatitis
What is increased conc of oxalate in urine assc. w/?
Intestinal malabsorption syndromes (like Crohn's) -> this is b/c you get calcium binding to lipids (lots floating around from fat malabsorption since you lose bile acids in feces) instead of oxalate -> so lots of free oxalate to form kidney stones
So Crohn = oxalate kidney stones!
Where are Paneth cells and what do they secrete?
At base of intestinal crypts
Secrete lysozymes and defensins -> so antibacterial
Parasite that causes biliary tract disease and cholangiocarcinoma? How do you get it and how do you tx it?
Clonorchis sinensis (chinese liver fluke)
From undercooked fish
Tx w/ praziquantel
Parasite that causes liver (hydatid cyst)? How do you get it and how do you tx it?
From dogs, sheep, ppl from endemic area (Mediterranean, ME, S. America, Iceland, Australia, New Zealand, Southern Africa)
Tx w/ albendazole, if resection don't forget to inject ethanol first (risk of anaphylaxis otherwise)
How do you tell which structure is eso on CT?
It's bet. trachea and vertebral body -> just identify trachea based on the fact that it is radiolucent (air)
Eso has no visible lumen on CT
Types of transporters involved in bile conjugation and what happens if they're inhibited?
PASSIVE organic anion transporters (OATP): uptake of unconjugated bilirubn -> so get increased unconj bilirubin in blood if inhibited
ACTIVE organic anion transporter (MRP2): spits conjugated bile into biliary system -> so selective inhibition will result in isolated conj hyperbilirubinemia -> get increased conj bilirubin in plasma and urine (NOT feces)
What's the pathogenesis of alcohol-induced hepatic steatosis?
Decreased in FFA oxidation secondary to excess NADH production (from the 2 enzymes that metabolize alcohol)
Where is fat digested? And where is it mostly absorbed (along w/ fat-sol vitamins) if there's no bile?
Duodenum: main site of digestion
Jejunum: main site of absorptin
If bile is there, lipid will just diffuse thru brush border membrane w/out needing transport protein
Where is bile absorbed?
Why are pt who had cholecystectomy less tolerant of large fatty meals?
They don't have storage place for bile so can't release large amount at once in coordinated fashion w/ meals
Problem is NOT w/ secretion or absorption of bile acid, which happens on a constant basis (have increased rate of enterohepatic circulation b/c of this actually)
Slow and incomplete gallbladder emptying. Pt is likely to develop?
Biliary sludge (from bile precipitation) -> precursor to stone formation
What lab do you follow elevated alk phos w/?
Alk phos elevated from bone or hepatic cause, GGT will help determine which one
Curling vs. Cushing ulcers?
Curling ulcers: prox duodenum; in pts w/ severe trauma or burn
Cushing ulcers: eso, stomach, duodenum; in pts w/ high ICP -> very prone to perforation
What is granulomatous gastritis?
Idiopathic & benign condition -> intramucosal epitheloid granulomas that cause narrowing of antrum secondary to transmural inflammation
What 3 things happen in lactase-deficient pp when put on lactose challengel?
Increased stool osmotic gap
Increased breath H+ content
Decreased stool pH
What kind of B12 deficiency does Diphyllobothrium latum cause?
Malabsorption type -> so impaired B12 absorption on Schilling test can't be corrected by oral IF
Most dangerous complication of UC? How do you dx it?
Toxic megacolon -> can lead to perforation
Dx w/ plain abdominal X-ray -> don't do barium contrast or colonoscopy b/c risk of perforation
What is the most common liver neoplasm in children? What's the conditions assc. w/ it?
Hepatoblastoma -> fatal if not resected
Assc. w/ FAP and Beckwith-Wiedemann syndromes
Most common site of gastric ulcers?
Lesser curvature of stomach at the border bet. acid-secreting (fundic) and gatrin secreting (antrum) mucosa
Most useful dx feature in acute calculus cholecystitis?
NOT US and seeing stones -> lots of ppl have stones that doesn't mean they have acute cholecystitis (features that are more suggestive are distended gallbladder, wall thickening, pericholecystic fluid, + sonographic Murphy sign)
Most useful tool is actually HIDA scan -> see no gallbladder filling (failed visualization) on radionuclide biliary scan
The increase in activity of what enzyme is implicated in colon adenoma?
COX-2 (overexpression bet. APC and K-ras step)
What gets crushed in SMA syndrome? What conditions predispose to this?
Crush transverse portion of duodenum -(SBO sx) and left renal vein
Risk factors: anything that causes diminished mesenteric fat (less cushion), lordosis, surgical correction of scoliosis (decreased SMA mobility)
Diff in cells involved in pathogenesis of UC vs. Crohn's?
Crohn: TH1 (granulomas)
Precipitating factors of hepatic encephalopathy?
Anything that alters ammonia balance
Excessive nitrogen load: GI bleeding (Hb converted to ammonia), constipation
Metabolic: incl increased dietary protein
What's globus hystericus?
Sensation of lump in throat w/out any structural abnormalities
Saliva composition as related to fluid flow rate?
If fluid flow rate is slow enough, salivary ducts will be able to reabsorb Na+ and Cl- and secrete more HCO3- and K+ out
If fluid flow rate is high, secretions approximate plasma conc
What receptor does gastrin stimulate in parietal cells?
What's the structure w/ increased pressure in portal HTN?
Don't think of anastomosis, think of blood that now isn't able to drain into portal vein b/c of increased pressure
So it'll be splenic vein HTN -> blood backs up and get splenomegaly in cirrhosis -> this is from expansion of red pulp
Favorite site for Crohn vs. UC?
Crohn: terminal ileum (rectal sparing)
Signs and sx of B12 deficiency. What GI hormone is overproduced?
B12 deficiency -> think pernicious anemia (this chronic atrophic gastritis causes loss of parietal cells over time -> so now less acid and IF are made, less secretin will be made as well -> gastrin increases b/c there's no acid to inhibit antral G cells)
Lactase deficiency results from defect on what level exactly?
Decreased GENE EXPRESSION
NOT at the protein level, posttranslational, etc.
What are incretins and what do they do?
GLP-1 and GIP (gastric inhibitory peptide)
Stimulates insulin release after sugar consumption independent of insulin release from blood glucose rise -> why you get more insulin release w/ oral sugar consumption than IV sugar
Signs of estrogen excess in cirrhotic pts besides the obvious stuff?
Obv stuff: gynecomastia, testes atrophy, decreased bony hair
Others are spider angioma, palmar erythema, Dupuytren's contractures
4 orgs causing diarrhea in HIV pts and how to distinguish bet. them?
CMV: most common -> ULCERS and inflammation, see large cells w/ basophilic inclusions in cyto AND nucleus
Cryptosporidum: inflammation but NO ulcers, see basophilic cells (protozoan) attached to brush border
MAC: chronic NOT acute, see necrotizing and nonnecrotizing granulomas, acid-fast bacili
Microsporidum: distortion of villus but NO inflammation, see small spores w/ diagonal or equatorial belt-like structures
Levels where eso, aorta, and IVC passes thru diaphragm?
"I 8 (ate) 10 Eggs At 12"
IVC at T8
Eso (and vagus trunks) at T10
Aorta at T12