The liver in Health and Disease Flashcards
How does unconjugated bilirubin travel in the blood?
bound to albumin
What is the bare area of the liver?
the surface not covered with peritoneum
How many segments is the liver described as having?
8
What two sources does the liver receive blood from?
hepatic portal vein - 75-80%
hepatic artery - 20-25%
Describe the anatomy of the biliary tree
hepatocytes secrete bile into the bile canaliculi which drain into the small interlobular biliary ducts and then into large collecting ducts which merge to form left and right hepatic ducts
What is the ampulla of Vater formed by?
the pancreatic and common bile duct uniting
What part of the duodenum does the bile duct drain into?
2nd part
What causes bile release?
presence of fatty acids in the lumen of the duodenum stimulate I cells to release cholecystokinin
CCK also stimulates pancreatic enzyme secretion and relaxed the sphincter of Oddi, allowing bile and pancreatic juice to enter the duodenum
What cell type comprises the mucosa of the gall bladder?
simple columnar
What is bilirubin conjugated with in the liver?
glucaronic acid
What form of bilirubin is soluble?
conjugated bilirubin
What are the three products of bilirubin diglucuronide when it is hydrolysed by bacteria in the gut?
urobilinogen
stercobilin
urobilin
How is urobilinogen excreted?
by the kidneys
What comprises a portal triad?
hepatic artery
portal vein
bile duct
What is a liver acinus?
elliptical area divided into three zones
Zone 1 - nearest to vascular supply
Zone 2 - transitional zone
Zone 3 - less well oxygenated
Which zone of the acinus will be most affected during ischaemia?
Zone 3
What are the two types of fatty liver disease?
non-alcoholic - pregnancy, obesity, genetic predisposition, hyperlipidaemia
alcholic
What drug can cause fibrosis of the liver?
methotrexate
What type of drug can cause a cholestatic pattern on the liver?
antibiotics
What drugs cause a neoplasm pattern on the liver?
steroids
Many synthetic androgenic steroids are capable of causing cholestatic liver injury and long term use of androgens is associated with development of liver tumors including hepatocellular carcinoma and hepatic adenoma.
What kind of drugs cause a fatty injury on the liver?
antiepilectics
Which part of the abdominal aorta supplies the liver and from which vetebrae level does the vessel emerge from the aorta?
coeliac trunk, T12
How can cimetidine sometimes causes gynaecomastia in men?
Cimetidine, is a H2 receptor antagonist, the drug is a potent inhibitor of P450 and exhibits antiandrogenic effects, hence less testosterone is produced
