CIULLA_LIVER FUNCTION & PORPHYRIN FORMATION Flashcards
Principal pigment in bile that is derived from hemoglobin breakdown
Bilirubin
From what system is bilirubin produced
reticuloendothelial system
Bilirubin is produced from the breakdown of ____.
hemoglobin from senescent red blood cells (RBCs)
Prior to transport to the liver, bilirubin forms a complex with _______.
albumin
Upon forming a complex with albumin, bilirubin is (conjugated/unconjugated) and (is/not) water-soluble.
unconjugated, not water soluble
Where is bilirubin conjugated
hepatocyte endothelial system
Product of conjugation of bilirubin and glucuronic acid
bilirubin diglucuronide (conjugated bilirubin)
Reaction of bilirubin and glucuronic acid is catalyzed by ________.
uridine diphosphate (UDP) glucuronyltransferase
T/F:
Conjugated bilirubin is water-soluble.
TRUE
Conjugated bilirubin is excreted into what form prior to storage in the gallbladder?
bile
Conjugated bilirubin is stored in the ______.
gallbladder
Pathways of urobilinogen
Intestinal urobilinogen: reabsorbed
Portion returns to the liver
Some enters the circulation for excretion in the urine
Once conjugated bilirubin is excreted into bile, and secreted into the duodenum in response to gallbladder stimulation, it is further reduced by anaerobic bacteria in the intestine to _______.
urobilinogen
Some bilirubin is oxidized by anaerobic bacteria for excretion in the stool in the form of ______.
urobilin
an orange-brown pigment that gives stool its characteristic color.
urobilin
a yellow discoloration that occurs when the bilirubin concentration in the blood rises and the bilirubin is deposited in the skin and sclera of the eyes.
jaundice
what concentration of bilirubin will jaundice be considered?
> 2-3 mg/dL
Elevated bilirubin deposits in brain tissue of infants, affecting the central nervous system and resulting in mental retardation.
kernicterus
Bile is secreted by _____.
liver
Bile is stored in the _______.
gallbladder
Composition of bile salts
cholic acid
chenodeoxycholic acid conjugated with glycine or taurine
the primary site in the
body for synthesis of waste products
liver
the primary site in the
body for d conversion of drugs to metabolites for
excretion in urine or stool
liver
type of jaundice which occurs when there is excessive erythrocyte destruction, as seen in hemolytic anemias, spherocytosis, toxic conditions, hemolytic disease of the newborn caused by Rh or ABO incompatibility
Pre-hepatic jaundice
type of jaundice where the rate of hemolysis exceeds the liver’s ability to take up the bilirubin for
conjugation.
pre-hepatic jaundice
prehepatic jaundice is characterized by an increased level of what type of bilirubin
unconjugated
type of jaundice which occurs when the liver cells malfunction and cannot take up, conjugate, or secrete bilirubin
hepatic jaundice
defect in the ability of hepatocytes to take up
bilirubin; due to transport problem of bilirubin from the sinusoidal membrane to the microsomal region
Gilbert syndrome
Gilbert syndrome is a transport problem of bilirubin to what sites?
from sinusoidal membrane to microsomal region
BILIRUBIN CONDITION (dec/inc)
Gilbert syndrome
mild increase in serum level of unconjugated bilirubin (1.5-3.0 mg/dL)
Partial or complete deficiency of UDP-glycuronyltransferase
Crigler-Najjar disease
BILIRUBIN CONDITION (dec/inc)
Crigler-Najjar disease
moderate to extremely elevated serum level of unconjugated bilirubin
defective liver cell excretion of bilirubin due
to impaired transport in the hepatocyte of conjugated bilirubin from
microsomal region to the bile canaliculi
Dubin-Johnson syndrome
Dubin-Johnson syndrome is an impaired transport in the hepatocyte of conjugated bilirubin to what sites?
from microsomal region to bile canaliculi
BILIRUBIN CONDITION (dec/inc)
Dubin-Johnson syndrome
increased serum conjugated bilirubin
mild increase in unconjugated bilirubin
Level of UDP-glycuronyltransferase is
low at birth;
Neonatal physiological jaundice
BILIRUBIN CONDITION (dec/inc)
neonatal physiological jaundice
increased serum unconjugated bilirubin
may be caused by hepatocyte injury such as
cirrhosis, bile duct injury such as Rotor syndrome, or neoplasms
Intrahepatic cholestasis
type of jaundice which occurs when an obstruction blocks the flow of bile into the intestines.
Posthepatic jaundice
BILIRUBIN CONDITION (dec/inc)
posthepatic jaundice
significantly increased serum conjugated bilirubin
increased serum unconjugated bilirubin
increased conjugated bilirubin in urine
decreased urine and fecal urobilinogen
In posthepatic jaundice, the stool appears (pale/dark) in color
pale
a condition wherein obstruction blocks the flow of bile into the intestines
extrahepatic cholestasis
extrahepatic cholestasis samples
gallstones obstructing common bile duct neoplasms (carcinoma of ampulla of Vater, carcinoma of pancreas) inflammatory conditions (acute cholangitis, acute pancreatitis)
result of chronic scarring of liver tissue turning it into nodules
cirrhosis
Causes of cirrhosis:
excessive alcohol ingestion for long periods of time
hemochromatosis
hepatitis complication
primary cancer of the liver is referred to as
hepatocellular carcinoma/hepatoma