LFTs Flashcards
What are the homeostatic functions of the liver?
Gluconeogenesis Protein metabolism. Fat metabolism Bilirubin metabolism. Acid/Base Balance. Heat production.
What is stored within the liver?
Glycogen. Iron. Fat. Vitamins A, B12, D, E, K. Copper and Selenium.
What are the metabolic functions of the liver?
Amino acid metabolism creates Ammonia
Ammonia + CO2 = UREA
UREA excreted renally.
Nucleoprotein from worn out cells is broken down to form uric acid, which is renally excreted.
The liver processes hormones such as insulin, glucagon, oestrogens and growth hormones.
It is the most important site for the metabolism of drugs and alcohol. Fat-soluble drugs are converted to water-soluble substances to facilitate excretion in bile or urine.
what are the synthetic functions of the liver
Albumin. Coagulation factors. Acute Phase Proteins. Vitamin A (but not in the building it sense) Bile.
Define Pre-Hepatic Jaundice
Increased destruction of red blood cells = increased amounts of bilirubin.
red cell abnormalities (sickle cell), hemolysing diseases such as malaria, very rarely drugs such as levodopa, NSAIDs and some antibiotics.
Define Hepatocellular Jaundice.
Results from the livers inability to transport bilirubin into bile. Causes are related to liver cell damage. For example alcohol use, hepatitis, potential certain drugs (salicylates, oral contraceptives, rifampicin).
Define post hepatic jaundice
Obstructive Jaundice.
Results from obstruction to the excretion of bilirubin.
Causes of large duct obstruction include gallstones, biliary duct strictures, sclerosing cholangitis (inflammation of the bile ducts) and carcinoma (particularly head of pancreas).
Causes of small duct obstruction include, damage to liver cells (by drugs and alcohol), viral hepatitis, bacterial infections and primary biliary cirrhosis.
Define Hepatitis
Inflamation of the liver with accompanying liver cell damage or death. Associated with viral infection, certain drugs or auto-immune
symptoms of hepatitis
Symptoms include jaundice, nausea, vomiting, loss of appetite, tenderness in the right upper abdomen, aching muscles, and joint pain. In severe cases, liver failure may result.
Define Cirrhosis
chronic damage to liver cells and the eventual formation of scar tissue (fibrosis).
Symptoms of cirrhosis
mild jaundice, oedema, confusion and haematemasis.
What causes a rise in ALT/AST
Hepatitis (viral or auto-immune) Excessive alcohol intake or alcohol related liver disease Liver inflammation. Inherited liver diseases Liver tumours Heart failure
What is ALT
Alanine aminotransferase (ALT)
an enzyme necessary for energy production.
It is present in a number of tissues, including the liver, heart, and skeletal muscles, but is found in the highest concentration in the liver.
What conditions would you expect a significant rise in ALT
The highest ALT levels are associated with acute and massive liver cell necrosis. E.g acute viral hepatitis, acute shock, paracetamol OD)
A persistent moderately raised ALT (10 x normal) is associated with chronic liver disease.
What is AST
Aspartate aminotransferase (AST)
] is also necessary for energy production
It is found primarily in the liver, but is in other organs as well. High levels in the blood can indicate liver disease, but may also indicate other systemic diseases.