March 16 - GI Flashcards Preview

Designated study period: daily cards > March 16 - GI > Flashcards

Flashcards in March 16 - GI Deck (50):
1

Osmotic laxatives

Polyethylene glycol, magnesium citrate

2

Pigment stones: two causes

1. Infection of biliary tract with bacteria or helminths. Causes release of beta glucuronidase which increases unconjungated bilirubin by deconjugating bilirubin

2, Crhonic hemolytic anemia

3

Opioids and gallbladder

Opioids can cause contraction of sphincter of Oddi. This increases bile duct pressures causing biliary colic

4

Graft-vs-host disease: liver

Lymphatic infiltration and destruction of small intrahepatic bile ducts, similar to what is seen in PBC

5

Riboflavin deficiency

Riboflavin used to make FAD which is involved in TCA cycle and electron transport chain. In TCA cycle, needed for succinate dehydrogenase.
Def causes stomatitis, chelitits, glossitis, seborrheic dermatitis, anemia

6

TCA cycle steps

1. pyruvate to oxaloacetate
2. oxaloacetate to citrate
3. citrate to isocitrate
4. isocitrate to alpha ketoglutarate + NAD to NADH
5. alpha ketoglutarate to succinyl coA + NAD to NADH
6. succinyl coA to succinate + GDP to GTP
7. succinate to fumarate + FAD to FADH2
8. fumarate to malate
9. malate to oxaloacetate + NAD to NADH

7

C diff colitis: toxins

enterotoxin A: causes watery diarrhea
cytotoxin B: causes colonic epithelial cell necoris and fibrin deposition

Both disrupt actin cytoskeleton, sirupting itght junctions

8

Lipid digestion: location

Digestion occurs in duodenum
Abosrption occurs in jejunum

9

Pus formation

Macrophages at site release IL-8 which calls in neutrophils

10

C3a vs C5a

C3a: chemotactic for basophils and eosinophils
C5a: chemotactic for neutrophils

11

Pancreatic pseudocysts

Occurs as complication of acute pancreatitis. Pancreatic enzymes leak out leading to inflammatory reaction. Granulation tissue forms and encapsulates fulid. Not a true cyst because it is lined by granulation tissue rather than epithelium. Over 4-6 weeks, granulation tissue develops into fibrosis.

12

Causes of intestinal atresia

Duodenal: failure of recanalization
Jejunal/ileal: vascular injury; decreased perfusion results in ischemia which results in narrowing or obliteration of a segment of bowel
Colonic: cause unknown

13

Arsenic poisioning: presentation, causes, treatment

Causes: insecticide ingestion, contaminated well water

Presentation
-acute: garlic odor, vomiting, profuse watery diarrhea, QT prolongation
-chronic: hypo or hyperpigmentation, hyperkeartosis, stocking glove neuropathy

Treatmnet: dimercaprol (chelator that increases urinary excretion)

14

Deferoxamine

Chelator for iron OD

15

CaNa2 EDTA

chelator for lead toxicity

16

Hydroxycobalaminin

antidote for cyanide poisoning

17

Methylene blue

treatment for methemoglobinemia

18

Hamartonatous polyps

Generally benign polys. Disorganized mucosal glands, smooth muscle, connective tissue. Sporadic or associated with Peutz Jehghers or juvenile polyposis.

19

Budd chiari syndrome: pathology and pathophysiology

Pathology: Dilation of sinusoids, perivenular hemoorhage
Cause: acute venous outflow obstruction in liver

20

Anal fissure: presentation and location

Presentation: sharp pain + bright red bleeding with defecation

Location: Posterior midline anus distal to dentate line

21

Gastric varices

Two causes
1) portal HTN as complication of cirrhosis
2) splenic vein thrombosis as complication of chronic pancreatitis or pancreatic cancer. Short gastrics drain the fundus to thrombosis of the splenic vein increases pressure in the short gastrics and causes gastric varices isolated to the fundus

22

Azygos veins and left gastric vein

Azygos: drains esophageal veins to SVC
L gastric: drains upper stomach and lower esophagus to portal vein

23

Crohns and gallbladder

Terminal ileum inflamed in Crohns. Can't reabsorb bile acids, resulting in increased cholesterol to bile ratio and gallstone formation

24

PAS stain

Stains glycoproteins bright pink. Good for looking at fungal cell walls, mucus secretions, BMs. In GI good for looking for T whippelii in sm bowel (gram po actinomycete)

25

Portal vein thrombosis

Portal HTN with liver unacffected as it si a perisinusoidal process

26

CA19-9

Pancreatic cancer marker

27

CA 125

Ovarian cancer marker

28

Carcinoembryonic antigen

GI cancer marker

29

Crohns vs UC inflammation

Crohns: Th1 process resulting in granulomas
UC: Th2 process resulting in mucosal damage

30

Indirect inguinal hernia: population,anatomy, cause

Population: male infants

Anatomy: superior to inguinal ligament. Lateral to inferior epigastrics. Protrudes through deep and superficial rings and is coveretd by all three fascial laters

Cause: Patent processus vaginalis

31

Direct inguinal hernia: popualtion, anatomy, cause

Population: old men

Anatomy: superior to inguinal ligament. Medial to inferior epigastrics. Protrudes through Hesselbach's triangle. Superficial ring only. Covered by external spermatic fascia only

Cause: weak transfersalis fascia

32

Femoral hernia: population, anatomy, cause

Population: women

Anatomy: protrudes through femoral ring, inferior to inguinal ligament

Cause: weak proximal femoral canal

33

Conjugated vs unconjugated bilirubin

Conjugated is water soluble and excess can be excreted in urine

34

Cavernous hemangioma

Most common benign tumor of liver. Most common in adults 30-50. Often asymtpomatic. No biopsy due to risk of bleeding.

35

Liver tumor associated with oral contraceptives

hepatic adenoma

36

Zenker diverticulum: pathophysiology and presentation

Pathophys: Abnormal action of cricopharyngeal muscles during swallowing (either spasm or failure to relax) results in increased pressure in the pharynx resulting in herniation of pharyngeal mucosa to form a false diverticulum

Presentation: dysphasia, coughing/choking sensation, halitosis, recurrent aspiration pneumonia

37

Biliary sludge

Forms due to gallbladder hypomotility. Precursro to gallstones

38

Cystinuria

Autosomal recessive. Increased urine cysteine. Early cysteine kidney stones.

39

Locations of heart chambers

LA: most posterior, can compress underlying esophagus
RV: lateral right heart
RA: anterior and superior
LV: left lateral heart

40

Diverticulitis: pathophys/pathology

Pulsion: increased pressure from straining leads to herniation of the mucosa and submucosa through weak areas of the muscularis

Most common in sigmoid colon

False diverciulum as does not include muscularis layer

41

Bethanechol

Muscarinic agonist

42

Cimetidine

H2 blocker

43

Reye syndrome

1. Hepatic dysfunction: vomiting, hepatomegaly, and increased LFTs. On path, microvescular steatosis (small fat vacuoles in hepatocyte cytoplasm)

2. Encephalopathy: due to increased ammonia

44

Two types of stomach cancer

1. Diffuse type: signet ring cells (nucleus pushed to side), non-gland forming, diffuse involvement due to loss of e-cadherin

2. Intestinal type: resembles colon cancer with well formed glands, grows as a well formed mass

45

Acute viral hepatitis: pathology

ballooning degeneration
councilman bodies: eosinophilic/acidophilic apoptotic hepatocytes
mononuclear infiltrate

46

Non-atrophic vs atrophic chronic gastritis

Non-atrophic: In antrum, usually due to H pylori, and leads to duodenal ulcers

Atrophic: inflammation in body and fundus leading to loss of acid producing cells, risk for cancer

47

Pathogenesis of cholesterol gallstones

Increased cholesterol
Decreased bile acids
Decreased phosphatidylcholine

48

Kaposi's sarcoma in GI

Can cause diarrhea. Diagnosed by scope which shows red/violet maculopapular lesions to raised hemorrhagic nodules. Biopsy shows spindle cells and BV proliferation

49

NEcrotizing enterocolitis: presentation, pathogenesis, and diagnossis

Presentation: distension and bloody stools in a preemie.

Pathogenesis: feeding introduces bacteria to bowel which proliferate excessively, invade the wall, and cause inflammation and ischemic necrosis

Diagnosis: thin curvilinear areas of lucency that parallel gut lumen on x-ray

50

Pathogenesis of hepatic steatosis in alcoholics

Incareds NADH produced by EtOH metab
Results in decreased FFA oxidation and accumulation of TGs