Step Review 3: GI, Repro Flashcards
Describe the rotation of the midgut in development
270 degree counterclockwise around SMA
What GI development defect is associated with Down Syndrome? Radiographic finding?
Duodenal atresia, double bubble finding
Olive mass in epigastric region? Associated with exposure to what antibiotics?
Hypertrophic pyloric stenosis, Macrolides
What ligament contains the portal triad?
The hepatoduodenal ligament
What ligament contains the splenic artery and vein?
Splenorenal ligament
What layers are Meissners and Myenteric plexus in? Function?
Meissner: Submucosa, secretes fluid
Myenteric: Muscularis, motility
How deep do ulers and erosions penetrate?
Ulcers into submucosa and inner or outer muscular layer while erosions are confined to the mucosa
Where do you find peyer patches?
Ileum
Are there villi in the colon? Crypts?
Crypts are present but no villi
What portion of the duodenum is compressed in SMA syndrome?
Transverse (3rd portion)
Vertebral levels of Celiac trunk, SMA, and IMA
T12, L1, L3
What are the three branches of the celiac trunk?
Common hepatic, left gastric and splenic
Which rectal vessels are part of the portal circulation?
Superior only, middle and inferior are systemic
Lymphatic drainage above and below pectinate line? Cancers?
Above: Internal iliac nodes, adenocarcinoma
Below: superficial inguinal nodes, squamous cell
What hepatic cells store vitamin A when quiescent and produce ECM when stimulated? Where are they located?
Stellate (ito) cells in the space of Disse
Where is zone 1 in liver? What affects it?
Periportal: ingested toxins and viral hepatitis (also where hepatic artery comes in)
What affects zone 2 of the liver?
Yellow fever
Where is zone 3 of the liver? What affects it? What is important here?
Pericentral vein. 1st affected by ischemia, contains cytochrome p450 and is thus most sensitive to metabolic toxins and the site of alcoholic hepatitis
What is the portal triad? What zone is it in?
Bile duct, portal vein branch and hepatic artery branch. Zone 1
What is a classic cause of painless jaundice?
Tumor in the head of the pancreas (ex. ductal adenocarcinoma)
What is in the femoral sheath?
Femoral vein, artery and deep inguinal lymph nodes BUT NOT FEMORAL NERVE
Where does a femoral hernia occur compared to the nerve, artery, vein, etc.
Very medial (femoral ring)
What covers direct hernias? What is this derived from?
External spermatic fascia only. External oblique
Watery Diarrhea, low potassium and low stomach acid?
VIPoma
Where is ghrelin produced?
Stomach
What converts pepsinogen to pepsin?
Acid (H+)
Where in the stomach do you find G cells? Pareital and Chief cells?
Antrum, body (note: D cells are also in the antrum)
How does gastrin mainly cause acid secretion?
By its action on ECL cells which release histamine rather than its direct effect on parietal cells
Describe the concentration of bicarbonate in pancreatic secretions based on flow rate? Cl-?
High flow is high bicarbonate (makes sense because this is the job). Low flow is high Cl-
What converts trypsinogen to trypsin?
Enterokinase/enteropeptidase (brush border enzyme in duodenal and jejunal mucosa)
What specialized cells do you find in peter patches?
M cells which sample and present antigens to immune cells (submucosa of ileum)
Where do IgA secreting plasma cells of the GIT eventually reside?
Lamina propria in ileum (post stimulation that begins in Peyer patches)
What catalyzes rate limiting step of bile acid synthesis? What are bile acids conjugated to?
Cholesterol 7 alpha hydroxylase, glycine or taurine
What is an intermediate in heme conversion to bilirubin? What enzyme mediates this step?
Heme oxygenase catalyzes the formation of bilverdin from heme (green in bruises)
Enzyme that conjugates bilirubin?
UDG-glucuronsyl transferase
Most common salivary gland tumor? Most common malignant? Which one is a benign cystic tumor with germinal centers and often bilateral?
Pleomorphic adenoma: most common (pleomorphic)
Mucoepidermoid carcinoma: most common malignant
Warthin tumor: bilateral, smoking, germinal centers
Cause of eosinophilic esophagitis?
Food allergens–> dysphagia causing rings and linear furrows
Dysphagia, IDA and esophageal webs with glossitis too
Plummer-Vinson syndrome
How does scleroderma cause esophageal dysmotility?
Esophageal smooth muscle atrophy
What are curling and cushing ulcers?
Curling: burns–> hypovolemia–> mucosal ischemia
Cushing: brain injury–> inc. vagal stimulation–> inc. ACh–> increased H+ production
What prostaglandin is protective to the gastric mucosa?
PGE2
What area of the stomach does H. pylori preferentially affect?
Antrum
What do you suspect if you see gastric mucosa with hypertrophied rugae?
Menetrier disease. Gastric hyperplasia of mucosa causes excess mucus production with excess protein loss and parietal cell atrophy with decreased acid production
Where do you most often see gastric intestinal adenocarcinoma?
Lesser curvature
Grossly thickened and “leathery” stomach wall. What is this called?
Linitis plastica (diffus gastric cancer- signet ring cells)
What is a Sister Mary Joseph Nodule?
Subcutaneous periumbilical metastasis from gastric tumor (also famous is the virchow node)
Where is the virchow node?
Left supraclavicular node
If you suspect a malabsorption syndrome, where should you start the workup?
Screen for fecal fat (Sudan stain)
HLA for celiac? Antibody that you might not know?
HLA DQ2 and DQ8. Anti-endomysial
What do you see on histology with celiac?
Villous atrophy, crypt hyperplasia, intraepithelial lymphocytosis
What area must be biopsied for celiac?
Duodenum
What does it mean with the D-xylose test if you see normal amounts in blood/urine? Low?
Normal: pancreatic insufficiency
Low: mucosa defects or bacterial overgrowth
What does low fecal elastase indicate? What pH will you see?
Pancreatic insufficiency which will also cause a decrease in duodenal pH
Describe Topheryma whipplei
Intracellular gram (+) that will stain PAS positive
Crohn or UC?
1) Cobblestone mucosa
2) Transmural
3) Psuedopolyps
4) Lead pipe
5) Crypt abscesses
6) Kidney stones
1,2,6 are crohn
3-5 are UC
What type of diverticula are most in GIT? Why?
False, only mucosa and submucosa out pouch (lack or have attenuated muscular is externa)
Where is diverticulosis most commonly located?
Sigmoid colon
Muscle involved in Zenker?
Inferior pharyngeal constictor
What types of tissue may be in a Meckel diverticulum?
Pancreatic or gastric
What mutations are associated with Hirschsprung disease? Increased risk for it with what?
RET, Down syndrome
Fibrous bands in midgut leading to obstruction?
Malrotation
Where do you see volvulus in infants? Elderly?
Midgut, sigmoid
Currant jelly stools?
Intussusception or acute mesenteric ischemia
Two possible lead points that can cause intussusception?
1) Virus–> peyer patch hypertrophy
2) Meckel diverticulum
What is angiodysplasia?
Tortuous dilation of vessels in GIT leads to hematochezia. Most often in cecum, terminal ileum or ascending colon
When should you pick hyper plastic polyp as an answer?
Basically never. They are small and non-neoplastic
Two syndromes with hamartomatous polyps?
PJ and juvenile polyposis
Pathway for adenomatous polyps? How do they present?
AK53 pathway (Chromosomal instability pathway-CIN) and although usually asymptomatic may present with occult bleeding
Saw tooth pattern of crypt, premalignant polyps. How do they arise?
Serrated polyps via CpG hypermethylation path with microsatellite instability and BRAF mutations
Genetics and chromosome with FAP? Which side do these carcinomas typically present on if it progresses that far?
APC tumor suppressor on c5, AD, left side
What do you suspect if you see supernumerary teeth?
Gardner: FAP +osteomas and congenital hypertrophy of retinal pigment epithelium
Turcot syndrome
FAP + malignant CNS tumor
What is the heritability of any polyp syndrome?
AD
Cancer risk with PJ? Lynch (HNPCC)?
Breast/GI for PJ
Endometrial, ovarian and skin with lynch
What are the genetics associated with Lynch syndrome?
AD mutation of mismatch repeater genes with subsequent microsatellite instability (right sided)
What part of the GIT is ALWAYS involved with Lynch syndrome? Are there polyps?
Proximal colon, NOOOOO (HNPCC)
Describe, in short, right vs. left sided colorectal cancer presentation?
Right side bleeds, left side obstructs
What type of endocarditis should be suspected with CRC?
Steptococcus bovis
Tumor marker for CRC?
CEA
Name the two pathways to CRC. What syndromes/problems are associated with each?
CIN (AK-53): FAP, sporadic (this is APC)
MSI: Lynch syndrome and some sporadic via serrated polyp pathway
What cells cause fibrosis in cirrhosis? What cells are in the nodules?
Stellate cells, hepatocytes
Whats free points you should always look for when given liver function test markers?
AST>ALT think alcohol
Why is gamma glutamyl transpeptidase better than ALP?
ALP can also increase with bone activity
What happens to platelets with liver disease?
Decrease due to decreased thrombopoietin and liver sequestration
What type of liver change is seen with Reye syndrome? Pathogenesis?
Microvesicular fatty change caused by decrease in beta oxidation by reversible inhibition of mitochondrial enzymes
What is a mallory body?
Associated with alcoholic liver disease and an intracytoplasmic eosinophilic inclusion of damaged keratin filaments.
Where do you see sclerosis in alcoholic cirrhosis?
Zone 3 (Peri hepatic vein)
What most likely leads to non-alcoholic fatty liver disease? How do you distinguish it from alcoholic liver disease?
Metabolic syndrome/ obesity, ALT will be> AST
Treatment for hepatic encephalopathy? What is fidaxomycin?
Lactulose (turns NH3 to NH4) and rifaximin or neomycin. Fidaxomycin is for C. diff.
Tumor marker for hepatocellular carcinoma?
AFP
What is a common benign liver tumor that you see blood on histology? What should you not do?
Cavernous hemangioma: do not biopsy due to risk of hemorhage
Liver tumor that is related to OCPs or steroid use
Hepatic adenoma
Tumor associated with arsenic and vinyl chloride exposure.
Angiosarcoma
Do you see JVD in Budd-Chiari syndrome? What should you immediately associate?
No, Polycythemia vera
Why do newborns get jaundice? Where can it cause problems?
Immature UDP-glucuronsyltransferase leads to unconjugated hyperbilirubinemia that can build up in the brain and cause kernicterus (specifically basal ganglia)
Does UV radiation on neonates conjugate bilirubin?
No
Inheritance of all of the hyperblirubinemia, wilsons disease and hemochromatosis?
AR
Specific finding in dubin johnson syndrome?
Black liver (conjugated bilirubin)
Which type of Crigler-Najjar might be survived? What helps it?
Type II, phenobarbital because it increases liver enzyme synthesis
Chromosome and defect in Wilson disease? What is a very close mutation disease?
Copper transporting ATPase (ATP7B gene on c13), Menkes disease
What are the levels of ceruloplasmin and urine copper in wilson disease? Where does it accumulate in the eyes?
Decreased ceruloplasmin, increased urine copper. Cornea
Mutation and chromosome for hemochromatosis?
HFE gene on c6 (C282Y>H63D)
Common cause of death with hemochromatosis?
HCC
Immediate association with light colored stool?
Biliary tract disease
Which biliary tract disease is intrahepatic only? Which is extra hepatic too?
PSC is both, PBC is in
Anti-mitochondrial antibody?
PBC
Onion skin bile duct fibrosis?
PSC
What does PSC increase risk for? Classic association and marker?
Increased risk for cholangiocarcinoma and gallbladder cancer. Associated with UC and p-anca
Relationship of bile salts and gallstones?
Decreased bile salts increases risk of stones
Is serum amylase or lipase more specific for pancreatitis?
Lipase (amylase is in mouth too)
What lines the cyst with pancreatitis?
Granulation tissue, not epithelium
Where does pancreatic adenocarcinoma arise from? Tumor marker? Odd risk factor?
Pancreatic ducts, CA 19-9, tobacco use
What cancer is associated with migratory thrombophlebitis?
Trosseau syndrome, pancreatic adenocarcinoma
What happens to blood pH when the stomach secretes acid?
It increases (HCO3 that was formed with the H+ is pushed into blood)
What kind of electrolyte disturbance can be caused by all antacids?
Hypokalemia
How does sucralfate work?
Binds to ulcer base providing physical protection and allowing bicarbonate secretion to reestablish pH gradient in mucus layer
What is misoprostol?
PGE1 analog. Increases gastric protection (don’t use in pregnant women, can cause abortion)
What is sulfasalazine?
Combo of sulfapyridine (antibacterial) and 5-aminosalicylic acid (anti-inflammatory) that is activated by colonic bacteria. Used for UC and the colitis component of Crohn disease
Odansetron mechanism and use? (SE?)
5-HT3 antagonist that decreases vagal stimulation (may prolong QT interval)
Metoclopramide MOA?
D2 antagonist that increases resting tone, contractility, LES tone and motility (don’t use in obstructed patients or Parkinsons)
Orlistat MOA?
Inhibits gastric and pan creating lipase leading to decreased breakdown and absorption of dietary fats
What is Ursodiol?
Nontoxic bile acid that increases bile secretion and decreases cholesterol secretion and reabsorption
Recurrent aphthous ulcers, genital ulcers, and uveitis. Pathology?
Behcet syndrome, which is due to immune complex vasculitis involving small vessels
Most common location for oral cavity SCC? Major risk factors?
Floor of mouth. Tobacco and alcohol
White patch on lateral tongue that cannot be scraped away. Pre-malignant?
Oral hairy leukoplakia, not pre-malignant rather it is EBV induced squamous cell hyperplasia
Salivary gland tumor composed of stromal (e.g. cartilage) and epithelial tissue. Major fact relevant to treatment?
Pleomorphic adenoma, high rate of recurrence due to incomplete resection (small islands penetrate through the capsule)
Parotid gland tumor that resembles lymph tissue (lymphocytes and germinal centers)
Warthin tumor
What part of the esophageal wall is involved in esophageal web?
Mucosa only
Painful hematemesis? Painless?
Painful: Mallory-Weiss
Painless: Esophageal varicies
Most common esophageal cancer worldwide?
Squamous cell carcinoma
When does esophageal cancer present?
Late thus poor prognosis
Where is lymph node spread from esophagus in:
upper 1/3
middle 1/3
lower 1/3
upper 1/3: cervical nodes
middle 1/3: mediastinal or tracheobronchial nodes
lower 1/3: celiac or gastric nodes
What is the pathogenesis of a cushing ulcer?
Increased ICP causes increased vagus stimulation and acid secretion
Where do you find parietal cells?
Body and fundus of stomach
HSR type in pernicious anemia?
HSR type IV (t-cells)
What layer of lymph tissues is only present in inflammation? Tumor that does this?
Marginal zone, MALToma
How to tell difference in benign peptic ulcers and malignant ulcers
Malignant are large and irregular with heaped up margins as opposed to sharply demarcated benign ulcers
What blood type increases risk for gastric carcinoma?
Type A
What do the intestinal and diffuse types of gastric carcinoma physically look like?
Intestinal: ulcer
Diffuse: thickened gastric wall (linitis plastica)
What vasculitis might affect the SMA?
PAN
Where is lactase found?
Brush border of enterocytes
What type of HSR is celiac?
Type IV
What cancers could celiac potentially cause late in the course?
Small bowel carcinoma and T-Cell Lymphoma (EATL)
Apparent celiac that responds to antibiotics? Where is it probably located?
Tropical sprue. Not duodenum like celiac but jejunum and ileum
Classic site of whipple disease? Pathogenesis?
Small bowel lamina propria. Bacteria builds up in lysosomes of macrophages, macrophages accumulate and compress lacteals, chylomicrons cannot be transferred from enterocytes to lymphatics
Low VLDL and LDL with malabsorption?
Possibly abetalipoproteinemia (AR deficiency of B-48 and B-100 with malabsorption due to defective chylomicron formation)
Why is carcinoid syndrome heart effect limited to right side?
MAO in lungs metabolize serotonin to 5-HIAA
Does smoking increase UC risk? What about Crohn?
Protects against UC, Increases Crohn risk
Is Crohn or UC more likely to cause bloody diarrhea?
UC
What type of biopsy is useful in diagnosing Hirschsprung disease?
Rectal suction biopsy
What provides the weak point in the colonic wall to allow diverticula to form?
Where vasa recta traverse muscularis propria
Where does angiodysplasia classically arise?
Right colon (think of it as the result of high pressure in right colon as diverticulosis is to the left colon)
Most common site of ischemic colitis?
Splenic flexure
Mouth and GI bleeds? Inheritance?
Hereditary hemorrhagic telangiectasia (AD)
Why might aspirin help prevention of colonic carcinoma?
At the same point as P53 on the AK53 progression there is an increase in COX expression that is needed as well. Aspirin prevents this and impedes progression
Which colorectal carcinoma syndrome do you associate with ovarian/endometrial cancer? Breast?
Ovarian/endometrial: HNPCC
Breast: PJ
Which side of tumor do you see HNPCC on?
Right, polyps are in the left