GI

Question 1

Beta glucuronidase

Answer 1

Produced by bacteria and injured hepatocytes. Cause pigmented gallstones

Question 2

Seven alpha hydroxylase

Answer 2

Turns cholesterol into bile acids. Deficiency causes cholesterol gall stones. Inhibited by fibrates

Question 3

1gram of protein or carbs
1 gram of fat
1 gram of EtOH

Answer 3

4cal
9cal
7cal

Question 4

Why does TPN cause gallstones

Answer 4

Because there is no stimulus to release cck and move gallbladder. This causes stasis

Question 5

Purpose of testing gamma GT?

Answer 5

To see if the cause of elevated alkaline phosphatase is biliary in nature, or from some other cause like bone deposition

Question 6

Acute acalculous cholecystitis

Answer 6

Exactly what it sounds like. Gallbladder inflammation from an acalculous source, mostly ischemia or stasis. Seen in really sick and hospitalized patients.

Question 7

Marker of HCC

Answer 7

Alpha feto protein

Question 8

Necrotizing enterocolitis

Answer 8

Causes abdominal distension and bloody stool in premature infants. Don’t have immunity to deal with bacteria, so they proliferate and cause bowel necrosis. Gas collections proliferate in walls

Question 9

First and second most common sites of CRC

Answer 9

Sigmoid then ascending colon

Question 10

Villous adenoma symptoms

Answer 10

Lower GI bleeding, partial obstruction, lots of mucous production causing secretory diarrhea

Question 11

Porcelain gallbladder

Answer 11

Complication of chronic cholecystitis 11-33% progress to cancer

Question 12

Histology of Reye syndrome

Answer 12

Microvesicular steatosis of hepatocytes. No jaundice, decreased mitochondria and glycogen without inflammation

Question 13

CREST

Answer 13

Calcinosis raynauds phenomenon esophageal dysmotility sclerodactyly and telangiectasia. Can cause fibrosis of connective tissue

Question 14

Th1 vs Th2 in IBD

Answer 14

TH1 is Crohns mediated granuloma formation

TH2 is UC

Question 15

Gynecomastia in cirrhosis

Answer 15

Estrogens cant be metabolized by liver so E:T ratio increases, especially because T is being bound by increased SHBG. This also causes spider angiomas, testicularatrophy, and decreased body hair

Question 16

Presenting symptom of primary biliary cirrhosis?

Answer 16

Pruritus

Question 17

Gallstone ileus causing fistula?

Answer 17

Causes fistula into small bowel. Stones can pass into small bowel, travel down to ileocecal valve, cause obstruction and air is forced into the biliary tree.

Question 18

Mechanism of hepatic steatosis

Answer 18

Triglyceride accumulation due to decreased fatty acid oxidation due to increased NADH in cells.

Question 19

Diphenoxylate

Answer 19

Opioid antagonist that decreases diarrhea

Question 20

Cancer from IBD is different from sporadic

Answer 20

Happens in younger patients, usually not polypoid rather flat, mucinous, multifocal and in proximal colon. Late apc mutations and early p53 mutations

Question 21

Postprandial alkaline tide

Answer 21

WHen parietal cells pump H into stomach, HCO3 is pumped into systemic circulation.

Question 22

PAS stains?

Answer 22

Glycoproteins

Question 23

Histology of Hep B vs Hep C

Answer 23

Hepatitis B has granular hepatocytes that include HBsAg, they also have ballooning degeneration.

Hepatitis C is characterized by lymphoid aggregates within portal tracts and macrovesicular steatosis

Question 24

Side effect of opioids and sphincter of oddi?

Answer 24

Cause contraction of sphincter of oddi causing increased pressures in bile duct and gallbladder. This is called BILIARY COLIC.

Question 25

SMA syndrome

Answer 25

Transverse duodenum (L3) gets trapped between SMA (L1) and aorta if the angle is too small. The angle closes with rapid loss of mesenteric fat, lordosis, and after scoliosis surgery. This causes obstruction

Question 26

LAC OPERON

Answer 26

LEARN THIS

Question 27

Conditions that favor cholesterol gallstone formation

Answer 27

High cholesterol (from deficient 7ahydroxylase, low bile acids, decreased phosphatidylcholine.

Question 28

Crigler Najjar

Answer 28

Causes kernicterus and is fatal. Much worse than Dubin johnson and rotor.

Question 29

Diffuse esophageal spasm

Answer 29

Nonperistaltic contractions are INCREDIBLY painful and mimics MI and unstable angina. Looks like corkscrew esophagus

Question 30

Chloride content of pancreatic secretions

Answer 30

Decreases with secretion of bicarb because they are pumped against eachother

Question 31

biliary sludge

Answer 31

Causes cholesterol gallstones (from stasis)

Question 32

Brown pigmented gallstones

Answer 32

Cauased by biliary infections

Question 33

Black pigmented gallstones

Answer 33

Caused by hemolysis

Question 34

Shiga-like toxin MOA

Answer 34

Decreases protein synthesis by preventing tRNA binding to 60S. Transmitted to bacteria via a phage.

Question 35

Main site of lipid absorption?

Answer 35

Jejunum

Question 36

Thiamine used for which enzyme?

Answer 36

Transketolase

Question 37

Where are anal fissures located?

Answer 37

Posterior midline (poorly perfused so sensitive mucosa) distal to the dentate line

Question 38

Where are the watershed areas of the colon?

Answer 38

Splenic flexure and distal sigmoid

Question 39

Pyoderma gangrenosum

Answer 39

Leg ulcer associated with CD and UC. Doesn’t correspond with flares.

Question 40

How do estrogen and progesterone affect the pathogenesis of cholelithiasis?

Answer 40

Estrogen increases HMG Coa reductase so more cholesterol made. Progesterone decreases bile acid secretion into gallbladder and decreases motility