Liver and GB part I covered in Exam II

Question 1

liver blood supplies

Answer 1

hepatic artery
hepatic portal vein: from GI to the liver
hepatic vein: from liver to inferior vena cava to the heart

Question 2

bilirubin formation

Answer 2

RBCs -> heme -> biliverdin
-> uncong. bilirubin + albumin (in serum) -> conjugation in the liver to produce conjugated bilirubin -> intestinal bacteria -> urobilinogen -> feces and urine

Question 3

circumstances with an increased urinary urobilinogen excretion

Answer 3

Excessive bilirubin production seen in hemolytic anemia

Inefficient hepatic clearance of the absorbed urobilinogen through enterohepatic circulation seen in cirrhosis or hepatitis

Excessive exposure of bilirubin to intestinal bacteria seen in constipation

Question 4

circumstances with a decreased urinary urobilinogen excretion

Answer 4

biliary obstruction seen in tumors

Question 5

mechanisms to protect against increased bilirubin

Answer 5

binding to plasma albumin
rapid uptake
conjugation
clearance

Question 6

potential health benefit of bilirubin

Answer 6

acts as an antioxidant like glutathione

Question 7

what type of bilirubin (conj or unconj) can be caused by excessive hemolysis

Answer 7

unconj bc the conjugation system becomes overwhelmed

Question 8

what type of bilirubin (conj or unconj) can be caused by abnormalities in the liver

Answer 8

it depends: the conj system is normal but clearance is abnormal or vise versa, we might have a mix of conj and unconj

Question 9

what type of bilirubin (conj or unconj) can be caused by the mechanical obstruction of bile flow after its formation

Answer 9

conj

Question 10

etiologies of increased unconj bilirubin in newborns

Answer 10

Increased in number of RBCs

Decreased RBCs’ life span

Decreased bilirubin clearance

Question 11

what cells send mitotic signals in the liver regeneration

Answer 11

Macrophages
Hepatic stellate cells
Liver endothelial cells

Question 12

etiologies of acute liver failure

Answer 12

acetaminophen, HAV, HBV, HCV

Question 13

clinical characteristics of acute liver failure

Answer 13

severe acute liver injury

hepatic encephalopathy

prolonged prothrombin time/INR

Question 14

pathophys of hepatic encephalopathy in acute liver failure

Answer 14

increased ammonia in the systemic circulation that crosses the BBB

in astrocytes, ammonia gets metabolized to glutamate -> astrocyte swelling -> increased ROS -> increased ICP
*watch for brain herniation

Question 15

pathophys of acetaminophen-induced liver injury

Answer 15

acetaminophen overdose: gluthotion storage gets depleted -> it gets metabolized by CYP450 -> formation of free NAPQI -> NAPQI binds to the liver proteins -> cells damage and death

Question 16

effect of acute alcohol intake with acetaminophen overdose

effect of chronic alcohol intake with acetaminophen overdose

Answer 16

no increased risk of hepatotoxicity due to the competition w CYP450

increased risk of hepatotoxicity through depletion of glutathione and increased synthesis and activity of CYP450

Question 17

alcohol metabolism

Answer 17

in the liver: acetaldehyde formation by ADH

in the gut: conversion of acetaldehyde to acetate by ALDH

Question 18

Spectrum of alcoholic liver disease

Answer 18

alcoholic steatosis -> steotohepatitis -> fibrosis -> cirrhosis