Liver and Nutritional Disease Flashcards
How much of the liver can be removed and still regenerate, assuming cirrhosis hasn’t taken hold? What percentage of the liver’s blood supply is arterial?
Up to 80%
25%
What are the functions the liver is responsible for?
- Storage and protein synthesis (e.g., vitamins, glucose, clotting factors)
- Secretion (e.g., bile salts)
- Excretion and synthesis of albumin and clotting factors
- Drug clearance and metabolism
What is the functioning unit of the liver called?
Hepatocyte
What structures do the portal tract join the hepatocytes to?
Blood supply and the bile duct
How long does liver failure have to persist to be considered chronic?
Over 6 months
What typically happens in the majority of acute liver failures once the cause is removed? What percentage of acute liver failures can be attributed to drugs?
They are self limiting and resolve
About 20-30%
What is chronic liver disease recognized by?
Permanent changes to the liver architecture
Which gender is at more risk of acute liver failure due to drugs?
Women
Why is the elimination of toxins and drugs essential for the liver?
To protect body systems
What is the primary function of CYP450 enzymes in Phase I liver metabolism? Which mechanisms do CYP450 enzymes use to cause this function?
To make the compound more hydrophilic
Oxidation, hydrolysis, and reduction
What happens in Phase II liver metabolism if Phase I doesn’t clear a compound? What type of enzymes are used in Phase II liver metabolism?
A larger polar group is conjugated
Transferase enzymes
What does the third phase of liver metabolism influence?
Effect, absorption, distribution, and elimination of the drug
What are the two main reasons for checking liver function tests (LFTs)? What two things does distinguishing between in LFTs help to confirm?
To confirm clinical suspicion and distinguish between types of jaundice
Acute hepatocellular injury and cholestasis
What are the tests of synthetic function?
Albumin and prothrombin time
What are the crude tests to distinguish liver damage?
Aspartate transaminase (AST) and alanine transaminase (ALT)
Alkaline phosphatase (ALP) and gamma glutaryltransferase (GGT)
Besides LFTs, what other tests can be done to assess the liver?
Ultrasounds and biopsies
Which marker is found in high concentrations in hepatocytes and is a primary marker of hepatocellular injury? What does this marker raised mean?
ALT
Liver cell damage
Which marker is found in hepatocytes, heart, muscle, and kidneys? What does this marker raised mean?
AST
Liver cell damage, but less specific than ALT
Where is ALP primarily derived from? What does a raised ALP indicate?
Biliary epithelial cells and bones
Bile flow obstruction
Where is GGT found? What does a raised GGT support?
Hepatocytes and biliary epithelial cells
Biliary obstruction
Where is bilirubin produced? What type of bilirubin is elevated in pre-hepatic jaundice? What does a decreased albumin level indicate? Where is albumin synthesized?
Haem breakdown in spleen, liver, and bone marrow
Predominantly unconjugated bilirubin
Severe hepatocellular damage
In liver
What does an AST:ALT ratio >2:1 suggest?
Alcoholic liver disease
What are some factors contributing to liver disease?
- Alcohol
- Viral infections (hepatitis A to E)
- Diet (obesity or anorexia)
- Diabetes (type 2)
- Drug abuse (prescription and recreation)
- Genetics (e.g., cystic fibrosis, hereditary hemochromatosis, Alpha-1 antitrypsin deficiency)
Which class of drugs can cause cholestatic jaundice with increased risk with age and in men?
Penicillin