Liver function Flashcards
What are the major functions of the liver?
• Carbohydrate metabolism
– Gluconeogenesis
– Glycogen synthesis and breakdown
• Fat metabolism
– Fatty acid, lipoprotein, and bile acid synthesis, cholesterol synthesis, and excretion
– Ketogenesis
– 25-hydroxylation of vitamin D
• Protein metabolism
– Synthesis of plasma protein,
coagulation factors and urea
• Hormone metabolism
– Steroid and peptide hormones
• Storage
– Glycogen, vitamin A, B12, iron
metabolism of bilirubin
What is hepatitis?
Inflammation of the liver, usually caused by infectious viruses (hepatitis
A, B, and C) or non-infectious causes (heavy drinking, drugs, allergy or obesity)
What is cirrhosis?
This is when the liver is damaged over a long period of time and develops permanent scarring making it unable to function well
What is Ascites?
A result of cirrhosis whereby the liver leaks fluid into the belly
What is the cause of Liver failure?
Many causes including infection, genetic disease and excessive alcohol
How do gall stones affect the liver?
They can get stuck in the bile duct draining the liver. This can lead to hepatitis and bile duct infection
What is non-alcoholic fatty liver disease?
This is when excess fat builds up in the liver with insulin resistance
What is Jaundice?
A condition where the skin, mucous and whites of the eyes turn yellow due to excess levels of bilirubin. It has many causes such as hepatitis, gall stones and tumors.
What is cholestasis?
A functional impairment of hepatocytes in bile secretion due to the obstruction of the biles excretory pathway
Explain the bilirubin test
Most of serum and plasma bilirubin is unconjugated. If there is an increased amount it can indicate hemolytic anemia or defects in its uptake by hepatocytes.
A common test for jaundice is noticing plasma bilirubin is 2 fold over the reference of 25umol/L
Hyperbilirubinemia can cause impaired metabolism and decreased excretion
Explain urine bile salts and urobilinogen test
Most urobilinogen is metabolized in the large intestine and a small portion is excreted in urine where as bile salts are not found in urine
An obstruction of the biliary passages can cause bile salts to leak into circulation and excretion in urine
Explain serum or plasma protein test
Serum protein includes albumin, γ-globulin, α1
-antitrypsin, caeruloplasmin,
α-fetoprotein, tranferrin, ferritin.
Explain serum albumin
It is the most abundant protein made by the liver and its synthesis depends on the extent of functioning liver cell mass.
Its long half life can make acute liver disease go unnoticed but it will be low in chronic liver diseases serving as a guide to severity.
Explain serum globulin
In chronic liver diseases where albumin is low, other proteins may be high due to polyclonal hypergammaglobulinemia
Explain prothrombin time test
PT is the best test for assessing liver dysfunction. It reflects the pathways of coagulation cascade and it has a half life of 6 hours. This is prolonged when more than 80% of its reserve capacity is lost hence the magnitude of prolongation is correlated with the severity of liver dysfunction.
