Physiology

Question 1

Main cause of liver abcess in developed countries

Answer 1

Bacterial infection from hematogenous spread, ascending cholangitis, peritoneal sources or trauma

Question 2

Diagnostic test for Cryptosporidium infection

Answer 2

Modified acid-fast stain in the stool (oocyst)

Biopsy: villous blunting, basophilic Cryptosporidium organism on the brush border

Question 3

The PPI supresses the activity of which transporter bomb?

Answer 3

H/K ATPase

Question 4

Function of beta glucoronidase in bilirrubin cycle

Answer 4

Deconjugates bilirrubin so can be reabsorbed by intestine

Question 5

Hereditary nonpolyposis colorectal cancer caused by a mismatch repair gene mutation

Answer 5

Lynch syndrome. MLH1 and MSH2 genes afected

Question 6

Enzyme located at duodenal and jejunal mucosa that activates trypsin

Answer 6

Enteropeptidase/enterokinase

Question 7

Severe complication of Clostridium difficile infection

Answer 7

Toxic megacolon

Question 8

Clinical features of VIPoma

Answer 8

Watery diarrhea, hypokalemia and achlorydia (pancreatic cholera).

Question 9

Inhibited enzyme by fibrates that ↑ cholesterol concentration in bile and contributes to gallbladder lithiasis

Answer 9

Cholesterol 7a hydroxylase

Question 10

Substance released by ileum and colon that binds entechromaffin-like cells and counteracts the cephalic and gastric phases of acid secretion

Answer 10

Peptide YY.

Inhibits gastrin-stimulated histamine release from ECLs

Question 11

Released enzyme by injured hepatocytes and bacteria that contributes pigment (brown) gallstones formation

Answer 11

Beta glucoronidase

Question 12

Vitamins that breastmilk lacks

Answer 12

Vit D and K

Question 13

Toxins A and B of C. difficile affect which part of the enterocyte and what do they cause?

Answer 13

Both disruot cytoskeleton integrity and stimulate inflammation.
Toxin A → diarrhea
Toxin B → necrosis

Question 14

Markers found in acute hepatitis A

Answer 14

Anti-HAV (IgM)

Question 15

Vitamin deficiency that causes ↑ serum methylmalonic acid level

Answer 15

Vit B12

Question 16

In Vit B12 deficiency, which enzyme is affected?

Answer 16

Methylmalonyl-CoA mutase

Question 17

Mechanism of action of Sofosbuvir and Ledipasvir in HCV infection

Answer 17

Prevents viral RNA replication and assembly

Question 18

Pathway which Leptine conducts to saciety

Answer 18

Inhibits neuropeptide Y (↓ appetite)

Stimulates production of alfa-MSH (↑ saciety)

Question 19

Site of action of Leptin in hypothalamus

Answer 19

Arcuate nucleus

Question 20

Serologic marker that indicates current Hep B infection

Answer 20

HBsAg (antigen found on surface of HBV)

Question 21

Mechanism due to Hep D virus superinfects

Answer 21

Depends on Hep B virus HBsAg coat for entry into hepatocytes

Question 22

Origin, function and stimulus of secretin

Answer 22

Duodenal S cells.
↑ pancreatic HCO3 secretion
Stimulated by gastric acid