Liver Anatomy Flashcards
where is the liver found
upper right quadrant of the abdomen, immediately below the diaphragm
Functionally how many lobes
2, L and R
anatomically how many lobes
4
left, right, caudate and quadrate
Diaphragmatic surface
superior upper surface of the liver
Visceral surface
faces adjacent abdominal organs (downwards)
incl porta hepatis and gallbladder
where is the caudate lobe
next to the inferior vena cava
where is the quadrate lobe
next to the gall bladder
falciform ligament
separates major left and right lobes and attaches liver to diaphragm and anterior abdominal wall
round ligament
found at the lower edge of the falciform ligament
gall bladder
accessory organ to the liver
rests in a recess on the inferior, visceral surface of the liver
function of gall bladder
stores bile if not required
where does the liver receive blood from
heart and GI tract
Hepatic portal vein
delivers poorly oxygenated blood from GI tract
rich in nutrients
drains blood from capillary beds of the GI tract including spleen and pancreas
hepatic artery
delivers oxygenated blood from the heart
splits into left and right hepatic arteries
Proportion of blood from each vessel
Aorta to hepatic artery 20-25% blood
hepatic portal vein 75-80% of blood
hepatic vein
carries blood away from the liver back to the heart
at the centre of each lobe is the central vein that drains into the hepatic vein then the vena cava
hepatocytes
cells in the liver
portal triads
at the edge of each lobule- formed by hepatic portal vein, hepatic artery and bile duct
blood vs bile flow
blood flows from portal triad towards central vein
bile flows in the opposite direction towards the porta triad (contains the bile duct)
what do hepatocytes do
absorb nutrients from the blood and produce bile that collects in the small bile caniculus
what does it mean to say liver cells are polarized
part of cell facing bile duct different to part facing blood circulation different
What do liver cells separate
sinusodial blood and canalicular bile
basal membrane faces
liver sinusodial endo cells
apical membrane contributes to
bile canaliculi jointly with the directly opposing hepatocytes
space of Disse
between haepatocyte cells and sinusodial endothelium
what is bile
excorine secretory product of the liver
contains HCO3-, cholesterol, lecithin, bile pigments and bile salts
what are bile salts important for
absorption of water insoluble fats
what are bile ducts lined by
hepatocytes
what is the blood sinusoid lined by
single layer of fenestrated endo cells
what do the sinusodial endothelial cells do
minimize any barrier for bi-directional transfer of small/soluble substrates between blood and extracellular space of Disse
act as a filter between lumen of hepatic sinusoid and hepatocytes
Kupffer cells
80-90% tissue machrophages in the liver
aka stellate macrophages
found in lumen of sinusoids, adherent to endothelial cells
role in host defence
stellate cells
found in subendothelial space between basolateral surface of hepatocytes and anti-luminal side of sinusodial endothelial cells
spindle shaped with oval nuclei
single stellate cell normally surrounds more than 2 nearby sinusoids
Involved in fibrosis formation
Bile duct circulation
bile transported down canaliculi, which empty into bile ductules and then bile ducts
Empties into hepatic ducts
Bile then enters duodenum or diverted to cystic duct in the gal bladder, which concentrates and stores it
Gall bladder fundus
wide end and projects from the inferior border of the liver
Gall bladder body
contacts visceral surface of liver
Neck of gall bladder
narrow and tapered, makes an s bend into cystic duct
Internally the mucosa spirals into the spiral fold that keeps the cystic duct open, stops it being blocked
Cystic duct
convoluted, connects gall bladder to hepatic duct
modifies bile to generate ductal bile
cholangiocytes
epithelial cells that line intra and extra hepatic ducts of the biliary tree
sphincter of oddi
at end of common bile duct
under hormonal control, whether it opens or not controlled by what you’re eating
production of bile
liver continuously produces bile into the bile duct that goes to the GI tract or gall bladder
