Jaundice and Chronic Liver Disease: Liver function and Liver Function Tests Flashcards
What is the synthetic functions of the Liver
Clotting factors
Gluconeogenesis, Glycogenolysis, Glycogenesis,
Albumin synthesis
Cholesterol synthesis, Lipoprotein
Triaglycerol synthesis
Produce hormones (angiotensinogen, insulin like growth factor)
What is the detoxification functions of the liver
Urea production from ammonia
Detoxification of drugs
Bilirubin metabolism
Breakdown of insulin and hormones
What is the immune functions of the liver
Combating infections
Clearing the blood of particles and infections, including bacteria
Neutralizing and destroying all drugs and toxins
What is the storage function of the liver
Stores glycogen
Vitamin A, D, B12 and K
Copper
Iron
What are the 8 Liver function tests
Bilirubin Alkaline phospherase aminotransferase gamma GT Albumin Prothombin Creatine Platelet count
How is bilirubin synthesised
Synthesied by heamm metabolism by RBC breakdown in the spleen
What is the non conjugated from of bilirubin
Bound to albumin for transportation
When does bilirubin become conjugated - soluble
In the Liver
When does bilirubin become elevated
Pre-hepatic: Haemolysis
Hepatic: Parenchymal (liver) damage
Post hepatic: Obstructive
JAUNDICE
What is amionotransferase (AST)
The enzyme present in hepatocytes
What is more specific ALT or AST (alanine aminotransferase)
AST - shows alcohol involvement
What does the ratio of ALT:AST indicate
Liver damage and if is due to alcohol (AST higher)
Where is alkaline phosphatase (ALP) found
The enzyme is present in the bile ducts
as well as bone, placenta and intestine
What does an elevation of alkaline phosphate indicate
Shows obstruction of liver infiltration
Also indicated problems in your gallbladder and bones
What is the non specific liver enzyme that is tested for in liver function tests
Gamma GT
What is is Gamma GT tested for in consideration with and why
alkaline phosphate (ALP) to see if the liver damage was due to alcohol
What causes elevated Gamma GT
Alcohol use
NSAID drugs
Tumours
Why is albumin an important test in liver function tests
To see Synthetic function of the liver
What does Low levels albumin suggest in Liver function tests
Suggests a chronic liver disease as the synthesis of albumin is no longer occurring
What can also cause low levels of albumin
Kidney disorder - protein lost in urine
Malnutrition - not enough protein in your diet
What liver function test tells the degree of liver dysfunction and the recovery of the liver
Prothrombin time (INR test)
Measure how long it takes blood to clot - Bleeding disorder indicated liver disease
What is the prothrombin time also used for in the diagnosis of liver disease
Used to calculate scores to decide stage of liver disease, who needs a liver transplant and who gets a liver transplant
Why is the creatine test of importance in liver function tests
As asses kidney function, therefore determines the survival of liver disease, as liver dependant on kidney function
This means its a critical test inconsideration of liver transplant
How does low platelets count occur in liver disease
Due to liver being an important source of thrombopoetin (releases hormone that stimulates platelet production)
and due to the occurrence of hypersplenism
How does splenomegaly occur from Liver disease
Advanced liver disease - cirrhosis can cause portal hypertension which results in splenomegaly causing an over reactive spleen and low platelet count
