GI Flashcards
Where do external hemorrhoids occur?
Distal to the pectinate line
Arise from ectoderm
Painful because they receive somatic innervation
Associated with squamous cell carcinoma
15 y/o presents with right sided facial swelling just beyond the angle of the jaw. Has been producing more saliva than usual. How would you describe the saliva?
Parotitis
Lower Potassium concentration than normal saliva
Initially saliva from duct acini is isotonic to plasma but intercalated ducts reabsorb sodium and chloride and add potassium and bicarb
A pt presents with hepatic encephalopathy (asrixis (flapping tremor), confusion, and lethargy) secondary to ammonia accumulation from cirrhosis. How would you treat?
Lactulose
When digested by bacteria lactulose acidifies the colon and converts ammonia (NH3; a weak base), to a non absorbable form (NH4)
24 hours post birth a child has failed to pass meconium. + chloride sweat test. What is the embryonic origin of the other structure that is involved?
Mesenephric duct
95% of CF pts are infertile due to improper development of the mesonephric duct (wolffian)
A pt with PUD is complaining of impotence and has gynecomastia on PE likely due to AE’s of his current treatment. What could he be switched to that would use the same mechanism as his current drug?
Ranitidine
Gynecomastia and impotence are associated with cimetidine (H2-blocker) but ranitidine doesn’t have the antiadrenergic effect
42 y/o japanese pt that recently immigarated presents to their oncologist with histology demonstrating signet ring cell carcinoma. Dx?.
Gastric cancer
Mucin displaces nuclei to the side making the signet righ. If found in the ovary, it is assumed the cell metastasized from the stomach (Krkenberg tumor)
Pt presents with abd pain, steatorrhea, weight loss, fatigue, joint pain. Bx shouls intraepithelial lymphoctyes, enterocyte damage, villous blunting. Dx and risk of developing?
Celiac dz
HLA-DQ2, HLA-DQ8
Risk of T-cell lymphoma
Ab against gliadin
Through which vessel would a vitamin A analog first enter the bloodstream
Thoracic duct
Fat soluble vitamins enter lacteals -> larger lmphatics -> thoracic duct -> subclavian v.
How do you treat PUD?
Amoxicilin, Clarithromycin, omeprazole
Pain improves with a meal = duodenal ulcer
78 y/o man presents with diarrhea, LLQ pain, fever. Small amount of blood in stool. Labs: WBC = 14, HCT 35%, Platelet = 250,000. Colonoscopy is contraindicated. Location of this condition?
Attenuated muscularis propria
Diverticulitis, often in sigmoid colon.
RF’s = low fiber diet and obesity
Note: diverticulitis can occur without bleeding
Normally when acidic chyme enters the duodenum, it will secrete secretin from duodenal S-cells. What does secretin do?
Stimulate release of bicarbonate from the pancreatic duct.
A 10 y/o boy presents with an X linked immunodeficiency, chronic GI inflammation, and negative nitroblue tetrazolium test. Which immune component is impaired?
Chronic granulomatous dz
Defect in NADPH oxidase in phagosomes (PMNs, Macrophages)
NADPH oxidase is located on the membrane and produces reactive oxygen species
70 y/o presents with 3 day LLQ pain, anorexia, constipation, leukocytosis. PE LLQ tenderness, guarding, rebound
diverticulitis (and possible perforation) due to increased intraluminal pressure leading to perforation of a bowel outpouching
Occurs in weaker part of the bowel.
53 y/o alcoholic has epigastric pain radiating to his back, n/v. Relief by leaning forward, elevated amylase, lipase. What would be found on PE?
Tapping over CN VII elicits a muscle twitch (Chvostek sign) and/ or carpopedal spasm during BP cuff inflation (Trousseau sign)
Dx - pancreatitis
Assoc with hypocalcemia
46 y/o IVDU with RUQ pain, yellow eyes, elevated LFT’s. HCV +. What is she likely to develop if left untreated?
Chronic Hep C
Fatigue, fever, jaundice, poor appetite, GI upset, ashy stools, dark urine, joint pain, cirrhosis
Only 20-50% of HCV positive develop cirrhosis
What type of cell does Salmonella infect in the GI?
Peyer Patches
M cells overlie the Peryer’s patch and act as APC’s
Salmonella attaches to M celland M cells initiate T cell response
A neonate presents with inability to swallow. She cough chokes and vomits during feeding. XR shows a tracheosphageal fistula. What abnormality would have been observed during pregnancy?
Polyhydramnios
Pr presents with abdominal pain and vomiting improved by bending forward. CT shows diffuse pancreatic enlargement with areas of necrosis. This is caused by inappropriate activation of which enzyme?
Trypsinogen
Pancreatic enzymes are synthesized by pancreatic acinar cells as zymogens. They drain into the ampulla of Vater in the descending duodenum. and t enterokinase cleaves trypsinogen into trypsin which can now activate the other pancreatic enzymes (chymotrypsin, elastase, carboxypeptidase etc)
Pancreatic obstruction or ischemia leads to abn activatation of trypsinogen causing acute necrotizing pancreatitis
Pt presents with progressive fatigue and pruritis x 6 mo. Elevated Alk Phos, ALT and positive antimitochondrial ab. Dx and what would the histology resemble?
Primary biliary cholangitis
Autoimmune mediated destruction of small and mid sized intrahepatic bile ducts causing cholestasis.
Bx = Lymphocytic inflammation and destruction of intrahepatic bile ducts with necrosis and micronodular regeneration. Similar to graft vs. host dz b/c T cells cause apoptosis of small intrahepatic bile ducts
A 4 week old with feeding intolerance is found to have pancreatic tissue encircling the duodenum. Cause?
Annular pancreas
ABN migration of the ventral pancreatic bud and fuse with the dorsal bud
Normally the ventral pancreatic bud gives rise to the uncinate process and main pancreatic duct
Usually asymptomatic but may present with duodenal obstruction or pancreatitis
How do you asses bioavailability of a po drug as compared to its IV abailability?
Bioavailability = fraction of administered drug that reaches the systemic circulation chemically unchanged.
Measure plasma concentration vs time and divide the area under the po curve by the area under the IV curve
A chronic alcoholic is presenting with cirrhosis. Before beginning this treatment which structure will have increased pressure?
Portal v.
progressive fibrosis causes portal HTN
Would also expect increased pressure in the superior mesenteric, portal, and splenic v.
Why does ascites occur in cirrhosis?
Kidneys sense decreased perfusion pressure due to partal HTN and activates the RASS system
tx - Na restriction and diruetics (furosemide and spironolactone)
Pt presents with GERD that is resistant to OTC antiacids. PE scattered telangiectasias, ulcers at the finger tips, calcium deposits in the soft tissue of the hands and elbows. Dx and Why the heartburn?
CREST syndrome
GERD due to fibrous replacement of the muscularis in the lower esophagus
CREST = Cacinosis, Raynoud, Esophageal dysmotility, sclerodactyly, telangiectasia
Increased risk of Barret’s esophagus and fibrous stricture formation
Following a cholecystectomy where will dietary lipids be absorbed?
Jejunum
Bile salts are secreted into duodenum where bile salts emulsify the end products of fat digestion and form micelles.
Micelles are passively reabsorbed in the jejunum
Removal of gallbladder doesn’t change this
A pt is seeking a drug for motion sickness. What side effects should she be warned about?
Antimuscarinic and antihistamines with antimuscarinic action (meclizine, dimenhydrinate)
AE’s = blurry vision, dry mouth, urinary retention, constipation
What 3 systems sense movement?
Vestibular
Visual
Somatosensory systems
A male presents with epigastric abdominal pain following binge-drinking. 4 weeks later has has a palpable upper abdominal mass and a cystic lesion on CT. Dx and histology?
Pancreatic pseudocyst (complication of acute pancreatitis) Collection of fluid rich in enzymes and inflammatory debbris. Histology = walls consist of granulation tissue and fibrosis Unlike a true cyst, pseudocysts are not lined by epithelium
Parietal cells secrete?
Gastric acid, IF
Chief cells secrete?
Pepsin
Mucosal cells secrete?
Bicarbonate
G cells secrete?
Gastrin. Stimulates digestion and is activated by phenylalanine, tryptophan and high calcium
Which Histamine receptor is active in digestion?
H2
H1 = allergies
A cholecytokinin stimulation test demonstrating incomplete gallbladder emptying. What finding would you expect in this pt?
Biliary sludge due to gallbladder hypomotility
Gallbladder actively abosorbs water from bile and hypomotility allows for the bile to concentrate and the sludge predisposes to gallstone formation with bile duct obstruction
A pt with PUD undergoes gastrectormy and they find enlargement of gastric rugal folds and parietal cell hyperplasia. What caused this?
Gastrin
Stimulates HCl secretion and trophic effect on parietal cells
Zollinger-Ellison syndrome
If the inferior mesenteric a. is ligated during a procedure, where does the left colon get collateral circulation from?
Superior mesenteric a.
What are the 3 main blood supplies to the GI tract?
Celiac trunk - stomach, duodenum, gallbladder, liver, spleen, pancreas
Superior mesenteric a. - SI and LI
Inferior mesenteric a. - SI and LI
A new born with drooling, feeding difficulties (choking, coughing), and cyanosis with feedings?
Tracheoesophageal fistula with esophageal atresia
Failure of primitive foregut to separate from airway
Polyhydramnios
CXR wouls show a stomach bubble
What testing can you use to confirm lactase deficiency?
Stool pH
Congenital = ar
Secondary = acquired resulting from inflammation or infection that causes injury to the mucosal brush border of the SI.
Incomplete hydrolysis of lactose leads to osmotic diarrhea and bacterial fermenatation will drop stool pH
A pt becomes hypotensive during a cholecystectomy and presents days later with abdominal pain and bloody diarrhea suggests injury where?
Ischemic colitisof the rectosigmoid junction (watershed b/w sigmoid a. and superior rectal a.)
In low flow states watershed areas become prone to ischemia. What are the 2 watershed areas in the GI tract?
Splenic flexure (SMA and IMA) Rectosigmoid junction (sigmoid a. and superior rectal a.)
Acute inflammation of the gallbaldder in the absence of gallstones
Acalculous cholecystitis
Occurs in critically ill adn has a high mortality. Tjhought to be secondary to gallbaldder stasis and ischemia.
Fever, RUQ pain, leukocytosis
Inflamed and enlarged gallbladder
In addition to being its own activator, trypsin also serves as?
Its own inhibitor by cleaving other trypsin molecules
What is hereditary pancreatitis?
Mutation in trypsinogen or SPINK1 genes
Leads to ABN trypsin that is not susceptible to inactivating cleavage by trypsin (becomes unregulated and causes autodigestion)
Recurrent attacks of acute pancreatitis
On endoscopy a pt bx reveals moderately differentiated tumor cells with keratin pearls and nests. Dx and RF’s?
Esophageal squamous cell carcinoma
Alcohol consumption and smoking
Presents with progressive solid food dysphagia
After initiating opioids for pain management a pt presents with new upper abdominal pain that makes it difficult to lie still. Whats going on?
mu opioids can cause cantraction of smooth muscle causing spasm of common bile duct (Sphincter of Oddi)
Can cause biliary colic (severe pain and cramping in RIQ)
D/c opioid and control pain with an NSAID
Pt presents with worsening fatigue and elevated alk phos. What should be checked next?
A moderately elevated Alk phos of unclear eitology should be followed up with gamma-glutamyl transpeptidase
GGP is predominantly present in hepatocytes and biliary epithelia and helps id if the alk phos is coming from the GI tract or bone
Following a gastrectomy a pt will require supplementation with?
Inj B12 due to the lack Intrinsic Factor
Pt presents with systemic skin and joint symptoms, hepatomegaly, and significantly increased transaminase levels. Also urticarial vasculitis rash and RUQ pain
Acute HBV
Sex and drugs
Look for elevated HBsAg and HBeAg and viral load
A pt is presenting with intermittent abdominal pain and a cholesterol-containing mass in the ileocecal valve dx and findings on cxr?
Gallstone ileus = a bowel obstruction caused when a large gallstone erodes into the intestinal lumen
CXR = pneumobilia (air in the biliary tract)
Pt presents with yellowing skin and SOB with exercise. Has been occuring since birth. CXR = hyperlucency of lung fields and flat diaphragm
Alpha1-antitrypsin deficiency
Panacinar emphysema + jaundice
A 3 wk old premy presents with abd distension, vomiting, and blood streaked stool. Abdominal XR shows thin curvilinear areas of lucency that parallel the bowel wall lumen. Dx?
Necrotizing enterocolitis (NEC) XR reveals pneumatosis intestinalis One of the most common GU emergencies in newborns esp preterms due to GI and immune immaturity. Impaired mucosal barrier allows bacteria to invade causing necrosis and the bowel begins to collect gas 30% die, survivors are at risk of bowel obstruction due to fibrosis
Older male pt presents with abd discomfort, loose stool, and weight loss. Bx stains brightly with PAS. Dx?
Tropheryma whippelii
PAS stains the glycoprotein in the cell wall of the actinomycete
An alcoholic presents with hematemesis and esophagus show varices. The bleeding is most likely coming from chronic shunting of portal blood to the systemic circulation through which v?
Left gastric
Which type of hernia can protrude into the scrotum and becomes larger with coughing?
Indirect
These are more common than direct hernias and tend to present on the right side.
Failure of the processus vaginalis to obliterate
Inferior epigastric vessels are medial
The excess of NADH due to excessive alcohol intake causes a decrease in which metabolic process?
Free fatty acid oxidation
NADH is formed by alcohol dehydrogenase and aldehyde dehydrogenase
Hepatic steatosis = trigllyceride accumulation within the hepatocellular cytoplasm
A gastric lesion is considered an erosion if it extends into, but not completely though, which layer?
Muscularis mucosa
Acute erosive gastropathy can cause upper GI hemorrhage that leads to melena
A 38 y/o man presents with steatorrhea despite a healthy diet, no travel, no occupational hazards, and no significant alcohol or smoking history. CBC, chem panel, and thyroid panels are WNL. What work up should be ordered next?
Stool test with Sudan III stain
Fats are typically the most severely affected macronutrient in malabsorption. Sudan III tests the stool for fat is is the most sensitive screen for malabsorptive disorders
A “moldy” grain in china can cause G to T mutation in p53 increases risk of?
Liver Cancer
aflatoxin causes G to T in p53 and increases risk of hepatocellular carcinoma
Aspergillus
45 year old construction worker presents with fatigue x 4 mo and SOB. PE - overweight, pale conjunctiva. Labs: low HCT, low MCV but Ferritin, Fe, and TIBC are WNL. Dx and what would be seen on smear?
Lead poisoning
Basophilic stippling
Tends to be through occupational exposure in adults. Syx of clicky abd pain, constipation, lead lines on gum, peripheral neuropathy, microcytic anemia with normal iron studies.
Lead inhibits the heme synthesis pathway by inhibiting gamma-aminolevulinate dehydratase
A pt has acute pancreatitis that resolves with fasting. He has no PMH and does not consume alcohol. What test should be ordered?
Serum triglycerides
Most cases of acute pancreatitis is caused by gallstones and chronic alcoholism.
Since he does not drink, it’s suspicious that the has inherited or acquired hypertriglyceridemia which causes acute pancreatitis when triglycerides are > 10
Which type of GI ulcer is very unlikely to be malignant?
Duodenal ulcers
Gastric ulcers can be malignant (MALT, gastric adenocarcinoma) and must be bx’d especially if they[re caused by H. pylori
Duodenal ulcers caused by H. pylori do NOT have a high risk of duodenal carcinoma and do not require bx
A 3 day old is brought in due to persistent vomiting and refusal to eat. Non bloody, green/yellow color. On laparotomy - normal duodenum with absence of large segments of jejunum and ileum and the remainder of the distal ileum winding around a thin vascular stalk. Dx and pathology?
Intestinal atresia
Atresia distal to the duodenum is due to vascular occlusion in utero.
“apple-peel” atresia is due to occlusion of the superior mesenteric and leads to a blind-ending proximal jejunum (a length of absent bowel and mesentery) and a terminal ileum spiraled around an ileocolic vessel.
What is the role of Somatostatin?
“Anti hormone”
Decreases activity/realease of: Gastrin, CCK, secretin, GIP, VIP, Insulin, Glucagon
Secreted by D cells (GI tract) and delta cells (pancreas)
What is the role of VIP?
Vasoactive intestinal peptide
Made by smooth muscle cells and PS ganglia and enteric nervous system
Rleaxaes smooth m. and sphincters throughout GI tract and increases secretion of electrolytes and water
VIPoma = high volume watery diarrhea
What is ileus?
When peristalsis is low
Tx with prokinetic agents:
1. Increase ACh (bethanechol, neostigmine)
2. Increase 5-HT (Metoclopramide, macrolides)
3. Increase d2 (also metoclopramide)
What are the retroperiteneal structures?
A DUCK Pear Adrenal glands Duodenum Ureters Colon Kidneys pancreas Esophagus Aorta Rectum
I cells of the stomach secrete?
CCK
Which ligament contains the portal triad?
Hepatoduodenal ligament
Which pancreatic structure is derived from the ventral primordium?
Main Pancreatic duct, inferior/posterior portion of the head
Dorsal pancreatic bud form the majority of the pancreatic tissue.
What occurs when the dorsal and ventral pancreatic buds fail to fuse?
Pancreas divisum
Pancreatic ductal systems remain separate and the accessory duct drains the majority of the pancreas
A pt is having his external hemorrhoids removed. Anesthesia would be needed to block which nerve?
Pudendal n.
External hemorrhoid below dentate line, covered by modified squamous epithelium and have cutaneous (somatic) inn from the inferior rectal n. (branch of pudendal n.)
Branches of pudendal inn perineum and external genitalia in males and females
What are the characteristics of internal hemorrhoids?
Above dentate line and are covered by columnar epithelium. Autonomic inn from inferior hypogastric plexus - sensitive to stretch but no pain, temp, or touch
What is the order of gene mutations in sporadic colon cancer?
- APC (early adenoma; normal mucosa to small polyp)
- K-ras (Late adenoma; polyps increase in size)
- p53 (Adenocarcinoma; malignant transformation)
10 y/o presents with diarrhea and tests positive for antibodies against tissue tranglutaminase. What would confirm the dx?
Duodenal biopsy would confirm Celiac dz
Villus flattening and intrepithelial lymphocyte infiltration
Following a gastrojejunostomy, a pt will need supplementation with?
Iron
Don’t Jump In
Iron Fist Brah
A pt had a small bowel resection due to bowel ischemia one year ago and is on total parenteral nutrition. He is presenting with gallstones and edema of the gallbladder wall, but he has no previous hx of gallstones. Why are they developing now?
Decreased CCK release due to lack of enteral stimulation
Total prenteral nutrition leads to decreased CCK release, biliary statsis and increased risk of gallstones.
Resection of ileum can also increase gallstone risk due to disruption of normal enterohepatic circulation of bile acids
What 3 physiological changes contribute to gallstone formation?
Increased cholesterol
Decreased bile acids
Decreased phsphatidylcholine
Bile becomes supersaturated with cholesterol -> aggregation is promoted by mucus hypersecretion, calcium salts, and gallbladder hypomotility
RFs for gallstone formation?
Fat, fertile, forty
Rapid weight loss
Glucose intolerance
hypomotility of the gallbladder (pregnancy, prolonged fasting)
18 t/.o presents with frequent pneumonias, sinusitis, and poor growth. Vas defrens were absent at autopsy. What other finding would be seen?
Distension and obstruction of pancreatic ducts (pancreatic insufficiency)
CF
Pneumonia with non-lactose fermenting GNR common (Pseudomonas, Burkholderia)
Characteristics of Kartagener syndrome (the help seperate it from CF)
Primary ciliary dyskinesia
Recurrent sinopulmonary infections and bronchiectasis but they do have vas deferns
Situs inversus of major internal organs (dextrocardia)
What is abetalipoproteinemia?
Inherited (ar LOF mutation in MTP gene), unable to synthesisz ApoB which is an important component of chylomicrons and VLDL. Lipids absorbed by the SI cannot be transported into the blood and accumulate in the intestinal epithelium resulting in entercytes with clear or foamy cytopalasm
Low cholesterol, triglyceride levels and risk for vit DEKA deficiency.
Presentation is similar to Celiac but no blunting on bx
Typical signs of Crohns dZ?
20-30 y/o - abd pain, weight loss, fatigue, fever,
Aphthous ulcers of the oral mucosa
Transmural inflammation
Cobblestone mucosa
Linear ulcerations
Skip lesions
Can develop enteroenteric fistulas and strictures
why do Crohns pts develop enteroenteric fistulas?
Transmural inflammation - causes both fistuals and strictures
Chronic inflammation -> edema and fibrosis -> narrowing of intestinal lumen (strictures)
Inflammation + necrosis -> ulcers -> if they penetrate the entire wall = fistula
What layers of the GI are affected in ulcerative colitis?
Mucosa and submucosa. Strictures and fistulas are NOT common
When a liver bx is taken from a viral hepatitis pt, the sample will be acidophilic due to?
Apoptosis
Acute viral hepatitis causes hepatocyte apoptosis and necrosis. apoptotic hepatocytes shrink, undergo nuclear fragmentation and become intensely eosinophilic.
AKA acidophilic bodies, Councilman bodies, and apoptotic bodies
Bx findings of GERD and it is caused by?
Basal zone hyperplasia
Elongation of the lamina propria papillae
Scattered eosinophils and PMNs
Cause = gastroesophageal junction incompetence and can be associated with nocturnal cough
Pt presents with a distal duodenal ulcer. Fasting gastrin level is at the upper limit of normal and rises in response to secretin. Dx?
Zollinger-Ellison syndrome
Neoplasm that secretes gastrin
heartburn, diarrhea is distal duodenal ulcer.
Diarrhea because other enzymes are inactivated by the inapropriate acid levels
Following a RUQ stab wound a surgeon occludes the hepatoduodenal ligament, but the bleeding continues. Which vessel is damaged?
IVC or hepatic v.
Which vessels are in the postal triad?
Common bile duct, hepatic a., portal v.
46 y/o man with poorly controlled HIV (CD4
Kaposi’s sarcoma
Involves skin and GI tract.
Characteristic lesions = reddish/violet flat maculopapular lesions to raised hemorrhagic nodules or polypoid masses
Bx = spindle cells, neovascularization, and extravasated RBC’s
What syx would be seen in a HIV pt with cryptoporidiosis
Profuse, watery, nonbloody diarrhea (CD
MOA of rifaximin?
Decreased intraluminal ammonia production
Used in hepatic encephalopathy
Other option is lactulose which increases conversion of ammonia to ammonium
Gastric mucosa is added to a solution with a pH indicator and urea. If the pH increases, this is a positive test for?
H. pylori
Urease converts urea to carbon dioxide
Initial syx in a pt with Right sided colon cancer?
Weight loss and progressive fatigue
Occult bleeding and syx of iron deficiency anemia
Initial syx in a pt with left sided colon cancer
Tend to infiltrate the intestinal wall and encircle the lumen, causes constipations of symptoms of intestinal obstruction
Initial syx in a pt with rectal adenocarcinoma
Tenesmus and small-caliber stool
A pt that has recently traveled presents with a liver bx revealing spotty hepatocyte necrosis and inflammatory cell infiltration on LM. Dx?
Acute Hep A
Initial syx = fever, anorexia, dark urine
A 4 wk old presents with dark yellow urine, pale-colored stools, jaundice, hepatomegaly. Elevated Total and Direct bili. Dx and mechanism
Biliary atresia
extrahepatic obstruction of bile ducts
Presents with jaundice, dark urine, and acholic stools in the first 2 months of life due to conjugajed hyperbilirubinemia
Bx - intrahepatic bile duct proliferation, portal tract edema, and fibrosis
Biliary tree is normal at birth but under goes immune-mediated destruction
Crampy abdominal pain improving with defication?
Irritable Bowel syndrome
NO - rectal bleeding, weight loss, elevated inflammatory markers
Common causes of small bowel obstruction?
Adhesions
Bulge (hernia)
Cancer
Dilated loops of bowel on XR
What causes intestinal ileus?
Low blood flow to gut (illness, post surgery)
Syx of Carcinoid syndrome?
Bronchospasm Flushing Diarrhea Right sided heart dz/mumur Only see syx if tumor has metastasized. Initial site = SI
On liver bx, LM shows extensive lymphocyte infiltration and granulomatous destruction of interlobular bile ducts. Describe the pt.
45 y/o woman with a long history of pruritius and fatigue who has pale stools and xanthelasma
Dx = Primary biliary cirrhosis
Autoimmune, destruction of bile ducts by granulomatous inflammation. Idious onset in middle aged women. Eventually develop signs of cholestasis (jaundice, pale stool, dark urine) and hypercholesterolemia (xanthomas)
Pt presents with worsening of heart burn that doesn’t respond to his usual anti acid regimen. Significant substernal pain with swallowing food. Why?
Developed an ulcer
New-onset odynophagia (painful swallowing) in the setting of chronic GERD = erosive esophagitis and ulcer formation.
Dx with upper endoscopy
When prescribing lipid lowering medications, which drug should be avoided in a pt with previous gallbladder dz?
Gemfibrozil (and other fibrates)
Reduce cholesterol solubility and promote gallstone formation by reducing bile acid synthesis.
MOA of fibrates?
Effective in hypertriglyceridemia b/c they upregulate lipoprotein lipase -> increased oxidation of fatty acids in liver and muscle
However, inhibit 7-a-hydroxylase in bile acid synthesis and decrease cholesterol solubility which promotes gallstone formation
If a pt is on fibrates should be monitored for?
myopathy. Especially when given with statins
46 y/o female presents with diarrhea, weight loss, andominal pain. Diarrhea started months ago and improves with fasting.
Endoscopy - postbulbar duodenal and jejunal ulcers. Dx?
Gastrinoma
Usually in SI or pancreas. Typically have peptic ulcers, abd pain/GERD, and diarrhea.
Associated with MEN1
Syx seen in VIPoma?
Pancreatic tumor presenting with diarrhea that persists with fasting, achlorhydria, and hypokalemia
Which lab abnormalities would predict prognosis in a pt with cirrhosis?
Prolonged PT, serum albumin levels, bilirubin levels.
AST> ALT (toAST) indicate hepatocellular damage
alk phos and gamma-glutamyl transpeptidase indicate biliary injury
A pt is hospitalized for sepsis and is intubated. 3 days later his hgb levels drop and there is bright red blood on suctioning. Why?
Physiologic stress
Usually caused by local ischemia in the setting of severe physiologic stress (shock, extensive burns, sepsis, trauma)
This pt likely developed stress-related mucosal dzand probably developed a Cushing ulcer
Why doe cushing ulcers develop?
direct vagus n. stimulation due to elevated intracranial pressure -> ACh is released and hypersecretion of gastric acid.
Curler = burns
Lab findings in acute pancreatitis
AST 2xALT (it is alcohol abuse)
Elevated serum lipase
MCV > 100 (macrocytosis, can be indipendent of folate levels)
65 y/o man presents with weight loss, jaundice, anorexia x 3 mo. Dark urine pale stools. PE - enlarged gall bladder. Number 1 RF?
Smoking - most important modifiable RF
Palpable nontender gall bladder + jaundice = pancreatic adenocarcinoma
RFS - age (>50), smoking, DM, chronic pancreatitis, genetics (MEN)
When the 3rd segment of the duodenum has a mass, there is risk that it will compress?
Superior mesenteric a.
3rd part of duodenum courses horizontally across the abd aorta and IVC at L3. The SMA is just anterior to the duodenum at this level
what is the MOA of diphenoxylate therapy?
Targets motility
opioid antidiarrheal
Binds mu opiate receptor in the gut to slow motility
Overuse -> euphoria and dependence
Can be used in combination with atropine to discourage abuse
What would be expected for gastrin, gastric pH, and parietal cell mass in pernicious anemia?
Elevated gastrin
High gastric pH
Decreased parietal cell mass
CD4+ mediated destruction of parietal cells. As they are destroyed their ability to secrete gastric acid decreases (high pH) and upregulate gastrin secretion. Low IF -> B12 deficiency
Why are Crohn’s dz pts prone to renal stones?
Reduced intestinal calcium oxalate binding
oxalate kidney stones.
Impaired bild acid absorption in the terminal ileum -> loss of bile acids in feces -> fat malabsorption. Lipids bind calcium ions and soap complex is excreted. Free oxalate is absorbed and forms urinary calculi
A pt presents with RLQ pain and has an inflamed swollen terminal ileum.
Bx - non-caseating granuloma
What cell type has infiltrated into their ileum?
Th1 helper t cells
Crohn’s dz. Increased Th1 -> increases production of IL-2, IFN-gamma and TNF causing intestinal injury.
Pt presents with fatigue, pruritus, hepatomegaly, and elevated alk phos. Dx and at risk for?
Cholestatic liver dz
At risk for malabsorption especially fat-soluble vitamins
A pt presents with abdominal pain, fever, diarrhea and is treated with abx. Bowel contents appear to be draining to the surface of the skin in the R lower abdominal quadrant. Dx?
Crohn dz Skip lesions Non caseating granulomas Transmural inflammation Linear ulcerations cobblestoning Fistulas, strictures, abscesses
Following a MVA a pt has abdominal pain and nausea. CT reveals a retroperitoneal hematoma. What is injured?
Contusion of the body of the pancreas
Basically make sure to remember the retroperiotneal organs
A 21 y/o male presents with mild jaundice after hiking and says that he has had similar episodes after fasting. Elevated Total bili, all other values are WNL
Gilbert syndrome
Likely in pts with no apparent liver dz who have mild unconjugated hyperbilirubinemia provoked by classic triggers (hemolysis, fasting, physical exertion, febrile illness, stress, fatigue).
Reduced levels of UDP glucuronyl transferases
Dx when unconjugated hyperbili persists but LFT, CBC, smear and ret counts are all WNL
Pt presents with predominantly conjugated chronic hyperbilirubinemia that is not associated with hemolysis. Dx?
Dubin-Johnson syndrome
Pt must have conjugated hyperbilirubinemia with a direct bilirubin faction of at least 50% and an otherwise normal liver fxn profile
4 stages of hepatic metabolism of bilirubin?
- Uptake from blood stream
- Storage within hepatocyte
- Conjugation with glucoronic acid
- Biliary excretion
Pt dies from GI hemorrhage. At autopsy the liver is very nodular. Dx?
Cirrhosis
Diffuse hepatic fibrosis with replacement of the normal lobular architecture by fibrous -lined parenchymal nodules.
Chronic viral hepatitis, alcohol, hemochromatosis, nonalcoholic fatty liver dz
Most common malignant hepatic lesion?
Metastasis from another primary site (breast, lung, colon)
NOT HCC
Metastases presents with multiple nodules leading to hepatomegaly
Pt presents with abd pain, chronic diarrhea, and recent weight loss. Previously had episodic pain but has become persistent and is worse after eating. Abd X-ray - calcifications in the epigastric area. Pt consumes alcohol regularly. What is causing his diarrhea?
Digestive enzyme deficiency
Chronic pancreatitis causing exocrine insufficiency and malabsorption
Characteristic findings of ulcerative colitis
Rectum is always involved
Inflammation is limited to mucosa and submucosa only
Continuous lesions
Bloody diarrhea
Can develop toxic megacolon which can lead to perforation
Significantly increased risk for adenocarcinoma
Which cytokine is involved in the mediation of pus accumulation?
IL-8
Produced by macrophages to induce chemotaxis and phagocytosis activity in PMN’s.
Others - leukotrience B4, 5-HETE, C5a
Pancreatic divisium presents as acture pancreatitis due to failure of fusion of?
Fusion of dorsal and ventral pancreatic ducts. Causes the pancreatic ductal systems to remain separate with the accessory duct draining the majority of the pancreas
Pt had a gastric bypass 3 years ago and has 6 weeks of watery diarrhea but bacterial counts are WNL. What is she deficient and in excess in?
SI bacterial overgrowth still occurs in the blind-ended gastroduodenal segment
Deficient in - Vit B12, A, D, E and Fe
Increased - Folic acid, Vit K
How do you calculate PPV?
TP/TP+FP
Who activates trypsinogen?
Enterokinase
Amatoxin found in paoisonous mushrooms inhibt?
RNA pol II (prevents mRNA synthesis)
Confirm dx with a urinalysis for alpha amanitin
Low levels of enteropeptidase would result in decreased activity of?
Trypsin
Enteropeptidase is a jejunal brush border enzyme that activates trypsin from trypsinogen
Enteropeptidase deficiency -> impaired protein and fat absorption -> diarrhea, FTT, hypoproteinemia
Newborn has projectile vomiting and an olive-sized mass on deep palpation in the right upper abdomen. Dx?
congenital pyloric stenosis due to hypertrophy of the pyloric muscularis mucosae
Mass = smooth muscle hypertrophy
What causes the down regulation of gastric acid secretion after a meal?
Intestinal influences
Cephalic and gastric phases stimulate gastric acid secretion.
A baby with Down’s syndrome has an umbilical hernia. What is the cause?
Incomplete closure of the umbilical ring
Reducible, asymptomatic , resolve spontaneously in the first few years of life
Liver bx on LM reveals large hepatocytes filled with finely granular, homogeneous, pale pink cytoplasm.
HBV
Granular, dull eosinophilic “ground glass” appearance
Liver bx with lymphoid aggregates within the portal tracts and focal areas of macrovesicular steatosis?
HCV
A pt that received Oral polio vaccine will have higher levels of what compared to the killed vaccine?
Duodenal luminal IgA
mucosal IgA response
Incomplete obliteration of the omphalomesenteric duct
Meckel diverticulum Most common congenital anomaly Connected to the ileum Presents with painless melena Can see a lot of ectopy
What is diagnostic of Strongyloides?
Rhabditiform larvae int he stool
Penetrates the skin -> iutoinfection with pulmonary syx
Tx - Ivermectin
MOA of polyethylene glycol?
Osmotic laxative
What is a good landmark to identify the appendix?
Teniae coli
Ribbon of smooth muscle that converges at the root of the appendix
Pt with crampy abdominal pain and vomiting has an abdominal X-ray reveals air in the gallbladder and billiary tree. Where is the gallstone lodged?
Ileum
Gallstone ileus = passage of a large gallstone through a cholecystenteric fistual into the small bowel and ultimately obstructs the ileum
Syx of small bowl obstruction and Xray revels gas in the gallbladder and biliary tree
Pt has iron deficiency anemia. Colonoscopy bx shows pleomorphic cells with large, dark nuclei forming irregular, crowded glands some with mucus. There are also lesions in the liver and lungs. Where is the original mass?
Ascending colon (Righ sided) Iron deficiency anemia is R sided Commonly metastasizes to liver and lungs
Pt has pernicious anemia due to autoimmune gastritis. What would be expected for : gastin, pH, parietal cell mass
High gastrin High gastric pH Decreased parietal cell mass As parietal cells are destroyed they are unable to secrete acid and this causes an upregulation of gastrin. Become B12 deficient due to loss of IF
Pt with jaundice, muscle rigidity, lethargy, and seizures. Which cause of this pt’s hyperbilirubinemia produces the neurologic syx?
Absent liver conjugation enzymes
Crigler-Najjar = ar, lack of UGT enzyme needed to catalyze bile glucuronidation. Unconjugated hyperbilirubinemia develops in infants -> kernicterus, death
Which biostat value becomes stronger in a population that has higher rates of a disease?
PPV
TP/(TP+FP)
PPV and NPV depend on disease prevelance iin the population.
Sensitivity and Specificity are not affected by prevalence
Pt has bloody vomiting due to a deep, bleeding ulcer on the posterior wall of the duodenal bulb. The ulcer penetrated which vessel?
Gastroduodenal
Lies along the posterior wall of the duodenal bulb and likely to be eroded by posterior duodenal ulcers
Can be a life threatening hemorrhage
Kid presents with bilateral cataracts and urine is positive for reducing substances. What enzyme is she deficient in?
Galactokinase
Lenticular accumulation of galactitol occurs in pts with galactosemia -> osmotic damage and cataracts. Cataracts can be the only manifestation of galactokinase deficiency
Infants born in the US undergo newborn screening so look for immigrants or adoptions
Pt has fatigue, flushing, abdominal cramps. Skin Bx reveals large clusters of mast cells that are KIT ( CD 117) +. Dx and other findings?
Systemic mastocytosis
Gastric hypersecretion
SM = ABN proliferation of mast cells and increased histamine release. His -> hypersecretion of gastric acid by parietal cells in the stomach + hypotension, flushing, pruritus
Chronic pancreatitis pt presents with hematemesis has a bleeding spot in the gastric fungus with a cluster of enlarged tortuous veins in the gastric fundus. Why?
Splenic v. thrombosis
Pancreatic inflammation - blood clot in the splenic vein -> gastric varices in the fundus
Pt presents with severe epigastric pain that began after a heavy meal. Which hormone provoked the atack?
CCK
Stimulates gallbladder contraction
Made in the duodenum and jejunum in response to faty acids and amino acids
Which retroperitoneal organ is fed by a foregut vessel?
Spleen
Most commonly injured organ in blunt trauma
What effects do:
Simvastatin
Cholestyramine
Have on hepatic cholesterol synthesis?
Simvastatin - decrease
Chlestyramine - increase (also increases bile acid synthesis)
Combination therapy -> synergistic reduction in plasma LDL level
Liver bx = fibrosis and nodular parenchymal regeneration
Cirrhosis
Older pt has choking spells, dysphagia, cough and recurrent pneumonia. Bad breath. Barium swallow reveals that the fluid can’t move all the way through the esophagus and there is a weird bulge. Dx?
Diminished relaxation of cricopharyngeal m. during swalling
Mucosa can herniate through a zone of muscle weakness in the posterior hypopharynx forming a Zenker (false) diverticulum.
Elderly pt with oropharyngeal dysphagia, halitosis, regurgitation, and recurrent aspiration
Following an MVA pt has shoulder pain, hypotension, tachycardia, and hiccups. Dx?
Spleen laceration and hemoperitoneum
Irritation of phrenic n. (C3-C5)
Pt has low urinary riboflavin excretion. Which enzyme is impaired?
Succinate dehydrogenase
Riboflavin is a precursor of the coenzymes FMN and FAD.
FAD - TCA cycle
Riboflavin (B2) deficiency = alcoholic. Key in the ETC
Most common benign liver tumor
Cavernous hemangioma
30-50 y/o
Congenital malformation
Bx - cavernous blood-filled vascular spaces of variable size lined by a single epithelial layer
Bx is not recommended because it can cause a fatal hemorrhage
Can resect if pt is symptomatic
Extraheptaic obstruction of bile ducts?
Biliary atresia
Jaundice, dark urine, acholic (pale) stools in the first 2 months of life due to conjugated hyperbilirubinemia
Bx - intrahepatic bile duct proliferation, portal edema, fibrosis
Elevated direct biliruibn, gamma-flutamyl transferase
Which immune response fights off Giardia?
Secretory IgA impairs adherence. Major component of adaptive immunity in Giardia.
Mostly affects duodenum and jejunum
Problem for kids with IgA deficiency, agammaglovulinemia, and CVID
Hemochromatosis is a defect in?
Intestinal iron absorption
HFE mutation, excessive intestinal iron absorption and organ damage (cirrhosis, DM, cardiomyopathy, atroopathy) due to Fe accumulation within parenchymal tissues
Pt has a deep peptic ulcer localized proximal to the lesser curvature of the stomach. The ulcer is likely to penetrate which artery?
Left gastric
gastric a’s - feeds lesser curvature
Gastroepiploic - feed greater curvature
Most gastric ulcers occur in the lesser curvaturse of the stomach at the border between acid-secreting and gastrin-secreting mucosa. Gastric a’s are the source of gastric bleeding the setting of ulcers
How would you confirm dx of celiac?
Duodenal bx - villus flattening and intraepithelial lymphocytic infiltration
NOT ileum
Screen with elevated IgA against tranglutaminase
Acute hepatitis syx following high risk sexual behavior?
HBV
Joint pain + lymphadenopathy + pruirtic urticarial rash
RUX pain, hepatomegaly, elevated LFT’s
A healthy baby that is exclusively breast fed should be supplemented with?
Vit D - lack of sunexposure, prevent rickets
Vit K - usually a shot at birth, prevent hemmorrhagic dz of the newborn
Excessive consumption of nitrites can cause?
Deamination of cytosine, adenine and guanine to
Uracil, hypoxanthing, and xanthine
If the ABN bases are not removed -> carcinogenesi
Child with abd pain and rectal bleeding. Surgical findings of a blind pouch connected to the ileum with a fibrous band attaching the end of the pouch to the umbilicus. Dx?
Meckel’s diverticulum
True diverticulum containing all parts of the intestinal wall (Mucosa, submucosa, muscular layers)
Remnant of the omphalomesenteric (vitelline duct)
2 feet proximal to ileocecal valve. Often has acid-secreting ectopic gastric tissue, ulcertation of the adjacent mucosa and lower GI bleeding (melena, hematochezia)
What is melena?
hematochezia?
Melena - dark sticky feces containing partly digested blood
Hematochezia - passage of fresh blood in the stool
On CT pt has a large mass extending from the greater curvature of the stomach impinging the splenic a. and v. Which other a. would be affected?
Short gastric
Splenic a. is a branch of the celiac and has several branches feeding the stomach and pancreas (pancreatic, short gastric, left gastroepiploic)
This tissue suppolied by the short gastric is vulnerable to ischemic injury due to poor anastomoses
LDL receptor gene mutations causing hepatocyte underexpression of LDL receptors?
Familial hypercholesterolemia
Accelerated atherosclerosis and early onset coronary a. dz
Following a crash diet a pt has a decreased angle between her SMA and aorta. Which structure is at risk of being compressed?
Transverse duodenum
Sumperior mesenteric artery syndrome -> syx of partial intestinal obstruction. Occurs due to diminished mesenteric fat, pronounced lodosis, or surgical correction of scoliosis
Goal of diphenoxylate therapy?
Decrease gut motility Anti-diarrheal optiate Given with atroping to discourage abuse - atropine will cause AE's if given in high doses (dry mouth, blurry vision, nausea) Could also use loperamide
Esophageal bx with solid nests of neoplastic squamous cells with abundant eosinophilic cytoplasm and distinct borders. Areas of keratinization and the presence of intercellular bridges
Squamous cell carcinoma
Presents with progressive solid and eventual liquid dysphagia and weight loss
Malignancy with probably poor prognosis
Hx of prolongeed alcohol and smoking
In a gastric bypass the device is placed around the cardiac part of the stomach. Which structure must the bad pass through?
Lesser omentum
Double layer of peritoneuum that extends from the liver to the lesser curvature of the stomach and beginning of the duodenum. Divided into hepatogastric and hepatoduodenal ligaments
H. pylori colonization causes a decreased number of somatostain producing antral cells. Depletion of these will cause which condition?
Duodenal ulceration
Due to increased gastric acidity (unchecked gastrin production following destruction of somatostatin-secreting cells in the gastric antrum)
Somatostatin producing cells = delta cells
Which antiemetic therapy is effective in GI insults (infection, chemo, anesthesia)
5HT3 receptor antagonists (Ondansetron)
Which antiemetic therapy is effective in vestibular nausea
Antihistamines (diphenhydramine, meclizine
Anticholinergics (scopolamine)
Which antiemetic therapy is effective in nausea associated with migraines?
DA antagonists (metoclopramide, promethazine)
Noncompliant HIV pt with bloody diarrhea x 1 mo. Colonoscopy - multiple hemorrhagic polypoidal lesions
Bx - spindle cells with surrounding blood vessel proliferation. Dx?
Kaposi’s sarcoma
Endoscopy - range from reddish/violet flat maculopapular lesions tto raised hemorrhagic nodules or polypoid masses
Bx - spindle cells, neovascularization, extravasted RBCs
Esophageal finding in CREST syndrome?
Fibrous replacement of the muscularis in the lower esophagus results in dysmotility
Presents with severe heart burn
