Liver structure and function Flashcards
Where is the liver anatomically?
upper right quadrant of abdomen underneath the diaphragm
What are the 2 major and 2 minor lobes of the liver?
right and left
caudal and quadrate
What is the porta?
The entry and exit point for all blood vessels, ducts, lymphatics and nerves to the liver
Where is the porta and what is its structure?
branched connective tissue capsule and the septa offer support
Explain the coming together of the hepatic duct to enter the sphincter of oddi
Connects with the cystic duct from the gallbladder to form the common bile duct which connects with the pancreatic duct to enter into the sphincter of oddi in the duodenum
What is the falciform ligament and where is it?
separates the left and right lobe
What does the coronary ligament attach the liver to?
The diaphragm
What area of the liver is NOT covered in peritoneum?
bare area as the coronary ligament passes over it
Where is the lesser omentum situated?
Between the liver and the stomach
What 3 things make up the portal triad?
hepatic portal vein, hepatic artery and hepatic duct
Is the liver in pentagonal, hexagonal or decagonal lobules?
hexagonal
How does the central vein drain into the IVC?
via the hepatic vein
What are the hepatic cords made from?
Hepatocytes
What are located between hepatocytes?
bile canaliculi
What are hepatic sinusoids?
Spaces between hepatic cords - blood channels
Is the blood from the alimentary canal oxygen rich/poor and nutrient rich/blood?
oxygen poor
nutrient rich
Where does hepatic portal vein blood and hepatic artery blood mix?
hepatic sinusoids
Where does blood in the hepatic sinusoids drain?
central vein, hepatic veins, IVC
What are hepatocytes responsible for?
bile synthesis
nutrient storage and interconversion
detoxification
Where does bile made in the hepatocytes drain to?
canaliculi and to hepatic duct
What is the main function of the liver?
production and secretion of bile
What is bile made up from?
bile acids, lecithin, cholesterol (synthesised in liver and solubilise fat)
toxic metals, bile pigment, bicarbonate
What is the one constituent of bile made from duct cells and not hepatocytes?
bicarbonate
What are bile pigments from?
breakdown products of haemoglobin from old/damaged RBC - extracted as blood passes through sinusoids
What extracts bilirubin from the blood?
hepatocytes
What colour does bilirubin make bile?
yellow
How does bilirubin effect faeces and urine?
colon bacterial enzymes modify it to brown
reabsorbed and excreted in urine
What are bile acids made from?
cholesterol in the liver
What does bile acids combine with and why?
glycine/taurine - amino acid
to increase water solubility
How are bile salts recycled?
via the enterohepatic circulation
Explain the movement of bile not into the gallbladder from the liver and back again
to the bile duct, duodenum, ileum, absorbed into hepatic portal vein and into liver
Where anatomically is the gallbladder?
inferior surface of the liver and it is a sac
What does the mucosa have to help with expansion in the gallbladder?
rugae
How does the gallbladder join to the common bile duct?
cystic duct
What does the sphincter of Oddi control?
bile and pancreatic juice entry to duodenum
What does the gallbladder do to bile?
concentrate it
absorb sodium and water
What does fat in the duodenum lead to the release of?
CCK
What does CCK do to the sphincter of oddi and secretions?
relaxes and gallbladder contracts
pancreatic enzyme and bile secretion
What does bile into the duodenum do to fat?
solubilise it
Generally what does secretin do and what does CCK do?
neutralisation
digestion
What do CCK and secretin do to gastric emptying?
decrease it
