Liver, LFTs, cirrhosis Flashcards
(162 cards)
List the normal functions of the liver:
Removing waste
Breakdown of drugs
Vitamin and mineral storage (A, D, K and B12, copper and iron)
Glycogen storage
Acute phase proteins
Amino acid, carbohydrate and lipid metabolism
Plasma protein and enzyme synthesis
Production of bile
Detoxification and immune functions
What is portal hepatus?
Point in which vessels enters the liver - hepatic artery, portal vein, common hepatic duct
What are the cells that make up the liver?
Basic structure made by hepatocytes
Kupffer cells
Sinusoidal epithelial cells
Stellate cells
Endothelial cells
Perisinusoidal cells
Liver-associated lymphocytes
Cholangiocytes
What are the recesses associated with liver?
Subphrenic recess - separates the diaphragm from the liver, divided into left and right by falciform ligament
Hepatorenal recess - between the liver, the right kidney and the right suprarenal gland
Describe the important ligaments of the liver
Falciform ligament - attaches it to the anterior abdominal wall
Hepatogastric ligament, hepatoduodenal ligament - to duodenum and stomach;
Anterior and posterior coronal ligaments, right and left triangular ligaments - to the diaphragm
What is the bare area of the liver?
Under the diaphragm, no visceral peritoneum
What are the connective tissues of the liver?
Capsula, portal tract (fibrous tissue, collagen I and III), parenchymal reticulin
Discuss the biliary system of the liver
Bile canaliculi - active transport, run in opposite way then blood, hectagonal arrangement, in space between 2 opposing hepatocytes and drains bile from the liver into the biliary ductules;
Bile ductules - lined by classic columnar epithelial cells - cholangiocytes and drain into the bile ducts;
Bile ducts - forms the right and left hepatic duct, connected to the gallbladder via the cystic duct and to intestine via the common bile duct
Discuss the hepatic lobule of the liver
Plate of hepatocytes and parenchyma divided up by sinusoids, surrounding central vein, branches of the portal vein and hepatic artery are located on the peripheral triad, during inactive periods many sinusoids are collapsed, blood drains into the central branches of the hepatic vein
What is the portal triad?
Branches of portal vein, hep artery and bile ducts run in parallel; according to the distance from the hepatic triad or vein the zones are distinguished
What is the space of Disse?
Separates the hepatocyte from the sinusoidal endothelium
Describe the 3 zones of the liver
Zone 1/periportal - closest to the afferent arteriole,
Zone 2 - ill-defined intermediate area,
Zone 3/perivenular - closer to the terminal hepatic veins
What functions are performed in the zone 1 of a liver?
Respiratory chain, citric acid cycle, fatty acid oxidation, gluconeogenesis, urea synthesis, production and bile excretion
What functions are performed in the zone 3 of a liver?
Glycolysis, glutamine synthesis, xenobiotic metabolism
Describe hepatocytes
Most abundant of liver cells lie in plates and cords, exchange material with blood at sinusoidal surfaces, arranged with microvilli and the fenestration for good slow exchange of blood and nutrients
What are sinusoidal epithelial cells and what are their features?
Line the liver cells, more leaky than capillary; their epithelium is fenestrated and lacks complete basement membrane
What are the features of stellate cells?
Storage site for retinoids, growth factors for hepatocytes, synthesise collagen in abnormal situations
How much and what type of blood supplies the hepatic artery?
30-40% blood supply, oxygenated blood
How much and what type of blood supplies the portal vein?
60-70% blood supply, this blood has already been through one capillary bed from small, large intestine, stomach, spleen and has low pressure, thinned walled with wide diameteer, superior and inferior mesenteric veins plus splenic vein join to form the portal vein
What drains blood away from the liver?
Connecting sinusoids that drain into the hepatic vein
What are the components of bile?
Water, electrolytes, phospholipids, bile salts or acids, bile pigments, cholesterol, haem waste products, and other substances from blood
How is bile produced?
Formed by the hepatocyte and modified down stream by absorptive and secretory properties of the bile duct epithelium
How is bile secreted?
Begins at the bile canaliculi, enters the hepatic ducts and then the bile duct
What are the functions of bile?
Bile acids are needed for fat absorption, mechanism to remove cholesterol and waste