USMLE things I don't know...18

jivirejo's version from 2017-08-03 18:39


Question Answer
what does a biopsy of the intestines look like w/ lactase deficiency? normal
where are most lipids absorbed in the gut?jejunum
what molecule is an allosteric activator of pyruvate carboxylase to increase gluconeogenesis? What does pyruvate carboxylase catalyze?Acetyl-CoA increases activity to convert pyruvate to OAA
where do most anal fissures occur?distal to the pectinate (dentate) line, in the posterior midline, b/c of less blood supply to that area
major complication of trying to aspirate a cyst from Echinococcus granulosus?anaphylaxis if cyst contents get into peritoneal cavity
what is used to text for malabsorption indepdendent of pancreatic function?D-xylose, it requires NO pancreatic enzymes
what happens to stool osmotic gap, breath hydrogen and stool pH with lactase deficiency?increased osmotic gap and breath hydrogen, decreased stool pH
best dx test if you suspect toxic megacolon in a patient with UC?flat plate plain X-ray
RLS in bile acid synthesis and enzyme inhibited by fibrates?7 alpha hydroxylase
how does estrogen contribute to gallstone formation?increased cholesterol synthesis via HMG-CoA reductase activation
how does a right side vs. left side colon CA present?left side = obstruction, right side = chronic slow bleed, so Fe deficiency
what are 3 common causes of pill esophagitis?tetracyclines, KCl, bisphosphanates
histological findings w. GERD?basal zone hyperplasia, elongation of lamina propria papillae, inflammatory cells
where is the HFE protein expressed? what is the abnormality in hemochromatosis?on basolateral surface of intestinal epithelial cells - it is defective, so it can't bind the Tf receptor to regulate Tf-Fe uptake into cells
what is the difference between a gastric erosion and ulcer?erosions do NOT get to the muscularis mucosa (musosa only), ulcers penetrate mucosa, muscularis mucosa and submucosa
what is the most common benign liver tumor?cavernous hemangioma
what can cause regression of hepatic adenomas?stopping OCPs
what type of hepatitis is really bad if you are pregnant? what kind of virus is it?Hep E, a norovirus, naked SS + RNA
why are chloroquine and primaquine both used to tx malaria?chloroquine kills form in blood stream (merozoites), primaquine kills schizoants in liver