Liver Structure and Function Flashcards
2 major and 2 minor lobes
right and left. caudate and quadrate
weight of the liver
~1.4kg
portal triad
hepatic artery, hepatic portal vein and bile duct
vessels entering and leaving the porta
hepatic artery, hepatic portal vein, lymphatic vessels, bile duct and nerves (hepatic nerve plexus)
what divides the liver into hexagonal lobules
septa
what is at each corner of the hexagonal lobules
a portal triad (artery, portal vein and hepatic duct)
at the centre of each lobule
central vein
drainage of a central vein
central vein –> hepatic veins –> IVC
what are hepatic cords
lines radiating out from the central vein. Made out of hepatocytes
spaces between hepatic cords
hepatic sinusoids
movement of blood in lobule
comes in through portal vein and artery –> travels through hepatic sinusoids
some to hepatocytes for bile synthesis and nutrient processing
some into central vein to drain into IVC
movement of bile in lobule
secreted by hepatocytes –> collected in bile duct of portal triad
6 components of bile
- bile acids
- lecithin
- cholesterol
- bile pigments
- toxic metals
- bicarbonate
which components of bile solubilise fat
bile acids, lecithin and cholesterol
bicarbonate is the only component of bile not secreted by hepatocytes. what cells secrete it
duct cells
predominant bile pigment
bilirubin
bilirubin is a breakdown product of what substance from old and damaged RBCs
haemoglobin
pathway of bile from liver back to liver again
liver –> bile duct –> duodenum –> ileum –> HPV –> liver
how much of our bile salts do we lose in a day
~5%
3 layers of gallbladder wall
mucosa, muscularis externa and serosa
duct leaving the gallbladder
cystic duct
role of gallbladder
to store and concentrate bile
how does the gallbladder concentrate bile
by absorbing Na and H2O
what is CCK
cholecystokinin - responsible for stimulation of fat and protein digestion
effect of fat in duodenum on CCK
CCK is released
what does CCK release trigger
- spinchter of oddi relaxtion
- gallbladder contraction
- pancreas secreting enzymes
- bile secretion
what does CCK inhibit
gastric emptying
Where are duct cells found
In the pancreas lining the ducts
