Chapter 31 - Liver Flashcards
What is the #1 hepatic artery variant?
Right hepatic off of SMA, 20%; courses behind pancreas, posterolateral to CBD
What is the most common variant of the left hepatic artery?
Left hepatic off left gastric artery; found in gastrohepatic ligament medially
What is the most common variant of the common hepatic artery?
Common hepatic off of SMA
What is the course of the falciform ligament? What does it contain?
Separates medial and lateral segments of the left lobe; attaches liver to anterior abdominal wall; extends to umbilicus and carries remnant of the umbilical vein
What is the course of the ligamentum teres? What does it contain?
Extends from falciform ligament on the undersurface of the liver; carries the obliterated umbilical vein
What separates the right and left lobe of the liver?
Line drawn from the middle of the gallbladder fossa to IVC (Cantlie’s line)
What is the name of the peritoneum that covers the liver?
Glisson’s capsule
What are the triangular ligaments of the liver?
Lateral and medial extensions of the coronary ligament on the posterior surface of the liver
The portal triad enters what segments?
IV and V
Gallbladder lies under what segments?
IV and V
What is contained in the hepatoduodenal ligament?
Bile duct, portal vein, hepatic artery
What are the positions of the contents of the portal triad?
common bile duct laterally, hepatic artery medially, portal vein posteriorly
What are the borders of the foramen of Winslow?
Superior: liver
Anterior: portal traid posterior: IVC
Inferior: duodenum
Portal veins carry what % of blood to the liver?
2/3 of hepatic blood flow
The middle hepatic artery most commonly branches from where?
Left hepatic artery
Primary and secondary tumors of the liver are most commonly supplied by what blood vessel?
Hepatic artery
The middle hepatic vein joins the left hepatic vein in what % of patients?
80%; other 20% go directly to IVC
Blood supply to the caudate lobe?
Receives separate right and left portal and arterial flow; drains directly into IVC via separate hepatic veins
Alkaline phosphatase normally located where?
Canalicular membrane
Where does nutrient uptake occur?
Sinusoidal membrane
What is the normal energy source for liver?
Ketones; glucose is converted to glycogen and stored
Where is urea synthesized?
Liver.
Amino acid oxidation for energy yields urea and CO2. Ammonia also converted to urea. Done through the urea cycle w/ N-acetylglutamate to regulate. It is dissolved in the blood. Carries nitrogen. Excreted in kidneys.
Urea loss can be used to measure muscle mass loss by estimating nitrogen from urea, then protein, then muscle mass.
What factors are NOT made in the liver?
VonWillebrand and factor VIII
What is the only water-soluble vitamin stored in the liver?
B12
What are the most common complications of hepatic resection?
Bleeding and bile leak
Which acinar zone is most susceptible to ischemia?
Acinar zone III, hepatocytes
What % of the liver can be safely resected?
75%
What is the breakdown of Hgb?
Hgb –> heme –> biliverdin –> bilirubin
Bilirubin is conjugated to what in the liver?
Glucuronic acid by glucuronyl transferase; improves water solubility
Where does urobilinogen come from? Reabsorbed and released where?
Breakdown of bilirubin by bacteria in the terminal ileum; reabsorbed in blood, released in urine
Components of bile?
Bile salts, proteins, phospholipids (lecithin), cholesterol, bilirubin
Bile acids are conjugated to what? What do these substances do? What are the primary and secondary bile acids?
Taurine or glycine, improves water solubility
primary bile acids: cholic and chenodeoxycholic
secondary bile acids: deoxycholic and lithocholic
What is lecithin?
Main biliary phospholipid, solubilizes cholesterol and emulsifies fats in the intestine
Where is the 1st place jaundice is evident?
Under the tongue
What is the ddx for elevated unconjugated bilirubin?
Prehepatic causes (hemolysis), hepatic deficiencies of uptake or conjugation
What is the ddx for elevated conjugated bilirubin?
Secretion defects into bile ducts; excretion defects into GI tract (stones, strictures, tumor)
What is Gilbert’s disease?
Abnormal uptake; mildly high unconjugated bilirubin
What is Crigler-Najjar?
Inability to conjugate; deficiency of glucuronyl transferase; high unconjugated bilis, life-threatening
What is physiologic jaundice of newborn?
Immature glucuronyl transferase
What is Rotor’s syndrome?
Deficiency in storage ability; high conjugated bilirubin. Liver looks normal.
What is Dubin-Johnson syndrome?
Deficiency in secretion ability; high conjugated bilirubin
What does it mean if you have elevated anti-HBs abs only?
Post-vaccination
What does it mean if you have elevaated anti-HBc and anti-HBs antibodies, but no HBs antigen
Had infection with recovery and subsequent immunity
What is the most common viral hepatitis leading to liver transplant?
Hepatitis C (RNA)
What hepatitis type is a cofactor for hepatitis B?
Hepatitis D
What is the hepatitis which will cause fulminant hepatic failure in pregnancy?
Hepatitis E
What is the most common cause of liver failure?
Cirrhosis
What is the best indicator of synthetic function in patients with cirrhosis?
PT
What is the mortality of acute fulminant hepatic failure?
80%
What is hepatic encephalopathy caused by?
Liver failure that leads to inability to metabolize; causes buildup of ammonia, mercantanes, methane thiols, and false neurotransmitters