Jaundice Jigsaw Flashcards
The liver’s cells (hepatocytes) excrete bile into
Canaliculi
Intercellular spaces between the liver cells
Canaliculi
These canaliculi drain into the right and left hepatic ducts, after which bile travels in the common hepatic duct and into the
Gallbladder
Has a capacity of 50 mL and concentrates the bile 10 fold by removing water and stores bile until a person eats
Gallbladder
Supplies the gall bladder
-a branch of the right hepatic artery 90% of the time
Cystic Artery
Venous return is carried either through small veins that enter directly into the liver or, rarely, to a large cystic vein that carries blood back to the
Portal vein
An imaging procedure that helps track the production and flow of bile from your liver to your small intestine
Hepatobiliary Scintigraphy (HIDA Scan)
Creates pictures of your liver, gallbladder, bile ducts, and small intestine
HIDA scan
Technetium-99m-labeled iminodiaceticacid analogues are a new class of organic anions taken up and secreted by hepatocytes into
Hepatic Bile
The only mechanism the body has to eliminate cholesterol
Bile acids in their feces
The primary bile acids differ from cholesterol in being composed of
24 carbon atoms
The mixture of primary and secondary bile acids and salts circulates between the liver and the small intestine, with storage in the
Gall bladder
If more cholesterol enters the bile than can be excreted, cholesterol may precipitate/crystallize in the gallbladder, leading to
Gallstone disease (cholelithiasis)
Gallstones are caused by a decrease of
Bile acids in bile
Gallstone disease can be caused by gross malabsorption of bile acids from the intestine, as seen in patients with severe
Ileal disease
Obstruction of the biliary tract, interrupting the enterohepatic circulation, can result in
Gall stones
An excessive feedback suppression of bile acid synthesis as a result of an accelerated rate of recycling of bile acids can cause
Bile acids
What percentage of patients with asymptomatic gallstones develop symptoms within 10 years
Only 25%
Generally indicated in patients who have experienced symptoms or complications of gallstones
Removal of Gallbladder (Cholecystectomy)
Drainage of pus from the gallbladder, which may be preferred in some cases to allow stabilization and later cholecystectomy
Cholecystostomy
If surgical removal of common bile duct stones is not immediately feasible, we can use
Endoscopic, retrograde sphincterotomy
Can prevent gallstone formation
Ursodeoxycholic acid (UDCA) treatment
Used in the treatment of cholestatic liver diseases, gallstone dissolution, and for patients with hep C
UDCA
UDCA is used in patients with hepatitis C virus infection to ameliorate elevated
Alanine aminotransferase levels
A bile acid with fewer hepatotoxic properties than endogenous bile acids
-competes with endogenous bile acids for absorption in the terminal ileum
Ursodeoxycholic acid (UDCA)
Ursodeoxycholic acid (UDCA) competes with endogenous bile acids for absorption in the
Terminal ileum
Appears to promote the endogenous secretion of bile acid and reduce the cytotoxic potential of endogenous bile acids
UDCA
Alters and reduces inflammatory cytokine production, protects cell membranes from disruption, and reduces the display of aberrant HLA antigens
UDCA
Breaks one of the methynyl bridges holding the four part ring together, releasing the green pigmented biliverdin, iron, and CO
Heme oxygenase
The products of heme oxygenase are shown to be
Cytoprotective
Biliverdin is a substrate for biliverdin reductase, producting the red-orange colored
Bilirubin
In the liver, adds two molecules of glucuronic acid to bilirubin, making the more water-soluble bilirubin diglucuronide
Bilirubin glucuronyl transferase
Bilirubin diglucuronide is secreted into the bile ducts and stored in the gall bladder until they are released into the
Intestine
Bacteria in the gut hydrolyze bilirubin and reduce it to a colorless
Urobilinogen
Gives urine its yellow color
Urobilin
May result due to excess hemolysis of red blood cells
Jaundice
Thallasemia, sickle cell anemia, G-6-P dehydrogenase deficiency, etc. may lead to
Jaundice
A plasma glycoprotein that binds extracorpuscular hemoglobin (Hb) in a tight noncovalent complex
Haptoglobin
Approximately 10% of hemoglobin that is degraded each day is released into the circulation and is thus
Extracorpuscular
Too large to pass through the glomerulus
Hemoglobin0haptoglobin complex
Low levels of haptoglobin are found in patients with
Hemolytic anemias
This is because the Hb-Hp complex has a short
Half-life
Thus, during hemolytic anemia when lots of RBC are breaking down and releasing Hb into plasma, we have low levels of
Haptoglobin
A condition characterized by yellow discoloration of the skin, conjunctivae, and mucous membranes as a result of widespread tissue deposition of the pigmented metabolite bilirubin
Jaundice
Stems from a mechanical obstruction of the bile duct, preventing the “draining” of conjugated bilirubin into the intestines
Obstructive jaundice
Both the liver uptake of bilirubin and the conjugation of bilirubin can be affected by
Hepatocellular Jaundice
Defect due to the complete absence of the EDP-GT gene
Criggler-Najar syndrome: Type I
What is the extent of jaundice in Criggler-Najar syndrome: Type I?
Severe, causing Kernicterus in the brain of the newborn
Defect due to a mutation in the UDP-GT gene
Criggler-Najar syndrome: Type II
What is the extent of jaundice in Criggler-Najar syndrome: Type II?
Benign
Defect caused by the reduction in transcription of UDP-GT due to a mutation in the promoter region
Gilbert Disease
What is the extent of Jaundice in Gilbert Disease?
Mild jaundice with physiological stress
Common and affects 2-10% of the population
-appears during or after adolescent years
Gilbert Disease
Defect due to a mutation in MRP2 resulting in diffuse deposition of coarse granular, dark brown pigment in hepatocytes
Dubin-Johnson
Appears during adolescence or early adulthood and is more common in iranian and moroccan jews
Dubin-Johnson
Jaundice is the only symptom of
Dubin-Johnson
Defect due to biallelic mutations in OAT1B1 and OAT1B3
Rotor
Rotor occurs shortly after
Birth or in childhood
What is the extent of jaundice in Rotor?
Mild conjugated and unconjugated hyperbilirubinemia
The jaundice seen in Rotor is
Intermittent
Low haptoglobin means
Intravascular Hemolysis
If direct levels of bilirubin are high
Obstructive Jaundice
Increased levels of unconjugated bilirubin
Hepatocellular Jaundice
