GI Review Flashcards
Compare gastroschisis and omphalocele
Gastroschisis: defect in abdominal wall, guts protrude without a covering.
Omphalocele: persistent herniation of guts through umbilical cord; guts protrude COVERED by peritoneum
What are two functions of stellate cells in the liver?
Stellate cells store vitamin A and secrete collagen (for fibrosis) when activated
What hormone induces Migrating Motor Complexes?
Motilin
What signaling molecule is decreased in achalasia?
Nitric Oxide (normally relaxes LES)
What does VIP do?
Causes relaxation of smooth muscle and sphincters. Causes increased water and electrolyte secretion.
Ashton Kutcher and Denzel Washington are real VIPs (achlorhydria, hypokalemia, diarrhea that’s watery in VIPoma)
Compare indirect and direct bilirubin
Indirect bilirubin is insoluble in water (unconjugated form).
Direct bilirubin is conjugated form.
Name three salivary tumors. Which is malignant?
Warthrin and Pleomorphic adenoma are benign. Mucoepidermoid is malignant
Compare intestinal and diffuse gastric cancer
Intestinal: Discrete mass. Increased risk with H pylori, smoking, toxins, etc.
Diffuse: no discrete mass, signet ring cells. Not associated with H pylori
How does food affect gastric and duodenal ulcers
Gastric: Greater pain with food (acid secretion)
Duodenal: Decreased pain with food (bicarb secretion)
What antibodies can be detected in Celiac? Which can be used in IgA deficiency?
Anti-tTG. anti-endomysial. Anti-deaminated gliadin peptide (anti-DGP has IgG form!)
Features of Whipple’s Disease (6)
Foamy macrophages, Tropheryma whipplei (g+), Diarrhea, Cardiac sx, Arthralgia, Neurologic Sx
What type of helper T cell is involved in crohn’s and UC?
Crohn’s: Th1 (angrier macrophages -> transmural infl)
UC: Th2
Compare pathogenesis of appendicitis in kids and adults
Kids: lymphoid hyperplasia
Adults: fecolith obstruction
Hirschsprung disease is associated with ___ mutation and failure of ______________ (developmental step).
Hirschsprung disease is associated with RET mutation and failure of neural crest migration.
Sessile serrated polyps are associated with what genetic changes (2)?
CpG hypermethylation and BRAF mutations
What are extra-GI manifestations of FAP?
Soft tissue tumors, hypertrophy of retina, impacted teeth, medulloblastoma (Many Traumatic Rectal Screenings)
What part of the colon is most involved in Lynch syndrome?
proximal (R colon)
What marker is used to monitor CRC recurrence?
CEA (carcinoembryonic antigen)
Diagnosis of spontaneous bacterial peritonitis
More than 250 neutrophils in ascites fluid
Where do you find Mallory bodies? What are they?
Alcoholic hepatitis. Mallory bodies are cytoplasmic inclusions of keratin.
What serum marker can be used to follow hepatocellular carcinoma?
alpha-fetoprotein
Pathogenesis of alpha-antitrypsin (2)
Misfolded protein builds up in hepatocyte ER, causing cirrhosis. Lack of antitrypsin in lungs allows elastase to destroy alveoli, causing emphysema.
What syndrome has completely absent UDP glucuronosyltransferase? What is elevated?
Criggler-Najjar syndrome (critter in a jar). Elevated UNCONJUGATED bilirubin
What is Gilbert syndrome?
Benign version of Crigler-Najjar (still have UDP, but it’s less active). Only get jaundice with stress.