liver and biliary system Flashcards
4 lobes of the liver
left, right, caudate and quadrate
functional anatomy of the liver
8 functional lobes
each has hepatic artery, portal vein and bile duct - each has portal triad
2 functional lobes of the liver
defined by the principle line
- traces the line of the middle hepatic vein
imaginary line roughly from the gall bladder fossa to the IVC
hexagonal lobules
reflect joining between the porto-caval systems
each has two inputs and 2 outputs
lobule concepts
blood and bile move in opposite directions
bile moves from the cell toward the triad
hepatic blood flow flows toward the central vein
portal vein blood flow also flows toward the central vein
one vein can drain up to 6 triads
classical lobule idea
concerned with venous drainage
supplied 6 triads
portal lobule idea
concerned mainly with bile drainage
liver acinus
emphasis on the secretory function of the liver
zones of liver acinus
defined by proximity to hepatic arterioles
zone 1 - closest
zone 2 - intermediate transitional zone
zone 3 - furthest from hepatic arterioles
zone 1
closest
cells are last to die if circulation is impaired and first to regenerate
zone 3
furthest from hepatic arterioles
first to show ischaemic necrosis and fat accumulation
last to respond to toxic substances
- site of drug and alcohol detoxification
hepatocytes
80% of cells in the liver
large polyhedral cells with large round nuclei
secrete bile apical surface has microvilli
tight junctions between cells
stellate cells
role in regeneration and Vit A storage and transport
space between hepatocytes and epithelial cells
narrow perisinusoidal space
plasma can freely enter through openings in sinusoids
macrophages attached to epithelium
hepatocytes are separated from the bloodstream by
discontinuous simply squamous epithelium of the sinusoids
liver capsule
sub capsular bleeds can be easily contained - better chance of survival
biliary system
an out pouching system of the foregut, mostly derived from the hepatic diverticulum
bile is
made in the liver, stored in the gallbladder
released into the duodenum, emulsifies dietary fats
bile is reabsorbed through the
colon
transported back to the liver via the portal system
components of the the biliary system
right and left hepatic ducts, combine to make the common hepatic duct
cystic duct and common hepatic duct combine to make the common bile duct
main pancreatic duct and the common bile duct connect at the major duodenal papilla
right and left hepatic ducts combine to create the
common hepatic duct
common hepatic duct combines with the scystic duct to form the
common bile duct
common bile duct and the main pancreatic duct join at
the major duodenal papilla
the gall bladder
concentrates bile by reabsorbing fluid
gall bladder epithelium
simple columnar with microvilli to help with water absorption
gall bladder sucks bile up using
vacuum pressure
pressure sucks bile back into the gallbladder
gall bladder smooth muscle
no muscular mucosa or submucosa
gall bladder mucous glands
no mucous glands
some around the neck - usually only in cases where the gall bladder is inflamed
gall bladder adventitia
can have serosa on one side and adventitia on the other
because its intraperitoneal
exocrine pancreas
series of tubolacinar glands
tubuloacinar glands
lobules with serous secretory units (acini)
very short intralobular ducts
apical cytoplasm full of secretory vesicles making digestive enzymes
