Week 6 Flashcards
List some of the major functions of the liver
Hormone metabolism
Glycogen storage
Synthesis of albumin
Detoxification
When is the sphincter of oddi open and when does it close?
The sphincter of oddi is closed between meals and opens during a meal
What does bile contain?
Bile acids Water and electrolytes Cholesterol IgA Bilirubin
What is meant by enterohepatic recycling?
The reabsorption of bile salts in the terminal ileum, which are then transported back to the liver
Drug metabolism often proceeds in two phases. Describe what happens in each of these phases
Phase 1 - Drugs are activated by oxidation/ reduction/ hydrolysis - this makes the drug more polar to allow for conjugation
Phase 2 - An endogenous compound is added to the drug to make it more polar
The cytochrome P450 superfamily are haem proteins. Where are these located and what is their function?
Located in the endoplasmic reticulum of liver hepatocytes
Mediate oxidation reactions in phase 1 of drug metabolism
What is meant by hepatic encephalopathy?
A hepatic coma in which there is an altered level of consciousness as a result of liver failure
In severe hepatic failure, detoxification of which substance can’t occur, causing it to accumulate?
NH3
Which membrane does HC03- and Cl- exchange occur at?
The duct cell apical membrane
How does hepatic portal blood concentration of bile salts affect their synthesis?
A low concentration stimulates synthesis of bile salts
A high concentration inhibits synthesis
Which 2 hormones affect bile secretion?
Cholecystokinin
Secretin
Which hormone causes gall bladder contraction and relaxation of the sphincter of oddi?
Cholecystokinin
What is meant by ‘Glucuronidation’
the transfer of glucuronic acid to the substrate.
forms either; amide/ ester or thiol bonds
Explain the blood supply to the liver
The liver has a dual blood supply, from the hepatic arteries and from the hepatic portal vein.
The liver has single drainage, via the hepatic vein.
Which 3 cell types are contained within sinusoidal spaces?
Endothelial cells
Kuppfer cells
Stellate cells
How is acute liver failure defined?
The rapid development of hepatic dysfunction in a previously healthy liver
Give some examples of ‘LFTs’ and ‘True liver function tests’
LFTs;
ALT
AST
ALP
GGT
True liver function tests;
Bilirubin
Albumin
Prothrombin time
List some of the clinical features of acute liver disease
Jaundice Lethargy Nausea Itch Pain
list some of the causes of acute liver disease
Hepatitis Drugs Cholangitis Alcohol Malignancy
What are the suitable investigations for acute liver disease?
History and examination
LFTs
Ultrasound
Virology
How is acute liver disease treated?
Supportive
Fluids
Increased calorie intake
Sodium bicarbonate bath, Cholestyramine or Uresodeoxycholic acid (for the itch)
Why is adequate nutrition important in patients with acute liver disease?
Acute liver disease is a hypermetabolic state meaning that there is increased energy requirements
Which drugs can potentially cause acute liver failure?
PARACETAMOL
ANTIBIOTICS
Which toxic metabolite can paracetamol accumulate as?
NAPQI