GI Flashcards
What causes a 40yo F to have distended gallbladder with patchy necrosis?
Acute calculous cholecystitis - inflam disease of gallbladder w/o evidence of gallstones or cystic obstruction
After partial pancreatic resection what enzyme are you deficient in? What will be normal?
o Pancreatic digestive enzymes that are secreted into the duodenum to digest polysaccharides
o Trypsin, lipase, trypsinogen
o Normal: D-xylose – monosaccharide whose absorption isn’t affected by exocrine pancreatic insufficiency.
Varices: gastric fundus
o Splenic vein thrombosis.
o Short gastric veins drain blood from gastric fundus into splenic vein
Varices: esophageal and gastric
o Left gastric veins
Gastric bypass surgery can cause small intestinal bacterial overgrowth (SIBO). This results in deficiency of what? It increases production of what?
Deficiency - Vit ADE, B12, Fe
Inc production - folic acid, vit K
Patients that have undergone total gastrectomy require lifelong supplementation of what?
Vit B12 (cant produce intrinsic factor that is normally secreted by parietal cells).
Describe the levels of breath hydrogen content, stool pH and stool osmolality in patients with lactose intolerance
breath hydrogen - increased
stool pH - reduced (inc short-chain FA acidify the stool)
stool osmolality - increased
Manometry - Systemic scleroderma
Dec peristalsis with dec tone at LES
Manometry - Achalasia
dec amplitude of peristalsis in mid esophagus; inc tone and incomplete relaxation at LES
Reduced # of inhib ganglion cells
Hereditary hemochromatosis is caused by a mutation in what protein? What is the function of the protein? patients with this condition have inc risk of what?
HFE protein - interacts with the transferrin receptor to form a complex that senses iron stores. W/o it, there is a falsely low Fe level detected
HCC, CHF, testicular atrophy/hypogonadism
Inhaled-anesthetic hepatotoxicity (esp from halothane) presents with fever, anorexia, nausea, myalgias, arthralgias, and rash. What do labs show?
Elevated LFTs, prolonged PT, leukocytosis, eosinophilia.
PT is prolonged bc liver cant synth factor VII
Where is vit b12 absorbed?
terminal ileum (deficiency with Crohns, surgical resection)
Where is vit b9 (folate) absorbed?
jejunum
where is iron absorbed?
duodenum and proximal jejunum
Adenoma to carcinoma sequence
- normal –> hyperprolif epithelium
- Hyperprolif –> adenoma
- Adenoma –> carcinoma
- APC inactivation, B-catenin accumulation
- K-ras activation
- p53 inactivation
What three receptors are located on parietal cells and increase gastric acid secretion?
Ach, histamine, gastric receptors Act synergistically (potentiation) - disrupt one will disrupt all.
How do you differentiate pseudoachalsia from malignancy from achalasia?
Manometry looks the same
Malignancy - progression is more rapid, asymmetric wall thickening with diff passing endoscope, enlargement of R supraclavicular nodes.
Acute blood loss with no abdominal pain in an elderly patient is indicative of what?
Diverticulosis - incidence inc with age
more fiber in the diet helps prevent
Treatment for mild to moderate extensive UC
Mesalamine, olsalazine, sulfasalazine
Why is an excess of H+ associated with ZE syndrome/gastrinomas?
Gastrin secreted by tumor cells is not subject to normal feedback control.
(Gastrin secretion is normally under neg feedback control by H+)
What drug is a negatively charged agent that forms a physical barrier against acid and pepsin?
Sucralfate (aluminum sucrose sulfate)
Neg charge binds to positively charged proteins at the base of ulcers
Caput medusae, caused by portal HTN is due to dilation of what vein
Paraumbilical v (systemic circ = superficial and inf epigastric v)
Hemorrhoids, caused by portal HTN is due to dilation of what vein
Superior rectal v (systemic circ = middle and inf rectal v)
Dietary lipids are primarily digested where?
After cholecystectomy, where will these lipids be absorbed?
- , Duodenum.
- jejunum (bile salts emulsify lipid breakdown products formign water-soluble micelles, facilitating lipid absorption here).
Rifaximin treats hepatic encephalopathy how?
decreases intraluminal ammonia production
Lactulose treats hepatic encephalopathy how?
Acidification: increases conversion of ammonia to ammonium
What drug is used to tx UC and Crohns disease and has SE of anorexia, reversible oligospermia, and serious skin reactions (SJS, erythema multiforme, TEN)?
Sulfasalazine - sulfa drug