how much does the liver weigh?
1400-1600 gms
what is the liver's dual blood supply?
- Portal vein - 60-70%
- Hepatic artery - 30-40%
Only ____% of the liver is needed to function
20%
Pathology of the liver
• Liver diseases, with rare exception, are typically insidious
• Clinical signs and symptoms develop weeks to years after the onset of injury
• Diseases may be primary (viral hepatitis, alcoholic liver disease) or secondary (cardiac
decompensation, disseminated cancer)
What are the common tissue responses to injury?
- Hepatocyte degeneration and intracellular accumulations
- Hepatocyte necrosis and apoptosis
- Inflammation
- Regeneration
- Fibrosis
Hepatic Failure
• The most severe consequence of liver disease
• May be either fulminant or the end stage of chronic damage
what functional capacity must be lost to be considered liver failure?
80-90%
what are the three main categories of hepatic failure?
- Acute liver failure
- Chronic liver disease (most common)
- Hepatic dysfunction without overt necrosis
Hepatic Failure is most often caused by
drugs (acetaminophen) or toxins, with other causes including Hepatitis A or B.
Acute liver failure
- Liver illness and encephalopathy within 26 weeks of diagnosis
- caused by massive hepatic necrosis
Chronic liver disease
- Most common route to liver failure
- End point of chronic hepatitis
Hepatic dysfunction without overt necrosis
- Hepatocytes are viable, but unable to function normally
- Ex: tetracycline toxicity, acute fatty liver of pregnancy
Clinical features of Hepatic Failure
- Jaundice, pruritis
- Coagulopathy
- Hyperammonemia is associated with the development of hepatic encephalopathy
- Fetor hepaticus - Distinct "musty" or "sweet and sour" odor
Hepatorenal syndrome
, Renal failure with severe chronic liver disease
- Sodium retention
- Impaired free-water excretion and decreased renal perfusion and glomerular filtration
rate
- Drop in urine output, associated with rising blood urea nitrogen and creatinine
- Poor prognosis
Hepatopulmonary syndrome
Classic clinical triad of:
- Chronic liver disease
- Hypoxemia
- Intrapulmonary vascular dilations
Cirrhosis
• 12th most common cause of death in the US
• Most often associated with alcohol abuse,viral hepatitis, biliary disease and non-
alcoholic steatohepatitis
what are the three morphological characteristics of liver Cirrhosis?
- Bridging fibrous septa
- Parenchymal nodules encircled by fibrosis
- Disruption of architecture of the entire liver
Clinical Features of Cirrhosis
- Often late in the disease course
- Anorexia, weight loss, weakness
- Death results from progressive liver failure, complications related to portal
hypertension, hepatocellular carcinoma
Portal Hypertension
• Increased resistance to portal blood flow
• Frequently related to cirrhosis (intrahepatic)
• Other causes include obstructive thrombosis (prehepatic) or right sided heart failure
(posthepatic)
what are the four clinical consequences of Portal Hypertension?
- Ascites
- Portosystemic shunts
- Congestive splenomegaly
- Hepatic encephalopathy
Jaundice
Yellow discoloration of skin and sclera (icterus) associated with the accumulation of
bilirubin in tissues
Cholestasis
The systemic retention of bile and other solutes, with the accumulation of bile pigment
within the hepatic parenchyma
Common causes of jaundice are
bilirubin overproduction (hemolytic anemias), hepatitis and obstruction of bile flow
T/F Pathologically, both unconjugated andconjugated bilirubin may accumulate
intissues
True
Review of bilirubin metabolism and elimination