Liver Flashcards
what does the liver develop from
an outgrowth of the gut
What is the function of the liver
carbohydrates + proteins –> fatty acids and triglycerides
Oxidise trilcericdes to produce energy
regulate blood gluoce concentration
detofification
bile secretion
syntehsie cholesterol
how does the liver regulate glouce concentration
through glyocgensis and glyconeogensis
what is the liver surrounded by
dense fibrous connective tissue and covring of mesthelial cells
what is the function of the mesothelium
acts as a shield against pathogens
what does the capsule also have c + e f
collagen and elastic fibres
blood vessels
what does the glission capsule send out
extensions into the hepatic parecnhyma which contributes to the supportive stroma
what is this covering derived from
simple squamous derived from the peritoneum
what are the different parts of the liver
Gibsons capusule
Parenchyma
Stroma
what does the Connective tissue do to the parenchyma
Divides it into lobules
what does the parenchyma consist of
ornaisgsed plates of heaptocytes
portal triad
central vein
what is the stroma continuous with
fibrous capdule of glission
what does the stroma contain
sinusoidal capillaries - vascular channels between paltes of hepatocytes
perisnsioundal spaces - lie between sinusoidal endothelium and hepatocytes
what ia the general structure for the classic hepatic lobule <=>
6 sides with a portal triad sourring each side with hepatic sinusoids going into the central vein
what is in the portal triad
portal vein
hepatic artery
bile duct
what is the hepatic sinusoids arranged around
the central vein
where does most of the blood come from
hepatic portal vein
rest is hepatic artery
what is the function of the portal vein
nutrient rich blood from the gastrointesitnial tract
what is the function of the hetpatic artery
provide oxygenated blood
what do terminal branches of the portal vein empty into
thin wall hepatic sinusoiids that are in contract with hepatocytes
what type of capillary is the hepatic sinusoids
fenestrated
what is the portal vein thin walls lined with
endothelium
why can the hepatic arteriole be identified
due to their thick muscular layer around the endothelium
what epithelium is the bile ductule lined with
simple cubodial
what is the main cells of the liver
hepatocytes
what are they
polyhedral epithelial cells
what do they form
but what are they actually
cords of liver cells
sheets or plates of cells
what is a sinusoids
the sheets of hepatocytes have spaed to allow blood flow
why is the cytoplasm of the hepatocytes esonphillic
because of their mitchodronia
what is there nuclei like
large spherical nuclei with nuclei have more than one nculei
what is the surface of each hepatocyte in contract with
wall of the sinusoid
(through perisinusoidal space)
what is a bile canilcusus
definition - projections - junctions - plasma
2 hepatocytes meet
first part of the bile duct
microvilli projections from the hepatocytes
joined by tight junctions
plasma is linited
what are the three types of lobules
classic hepatic
portal
hepatic acinus
classic hepatic lobule
drains blood from the portal vein + hepatic veins into the central vein or hepatic vein
what is the classic lobule useful for
endocrine function producing factors for the uptake of plasma
what is portal lobule
drains bile from hepatocytes to the bile ducts
what is this useful for
exocrine function
what is the shape of the portal lobule
triangular
central veins and three classic lobulaes at its angle
what is the hepatic anius
supplies oxygenated blood to hepatocytes
what does the hepatic acinus look like
irregular ovual
from the two portal triadards to the two cloest central veins
what are the different zones of the hepatic acinus
Zone I - hepatocytes closeest to the hepatic arteriole gets the most oxygen and nutrients
Zone III - closeest to the central vien least oxygen
what does being in zone one allow for function
oxidative metbaolsim functions such as proteins syntehsis
what are the sinusoids lined with
endothelial cells
what is the space of Disse / perisinsoidal space
a small space between the lining of the sinusoid and the hepatocytes
what projects into this space
microvilli of the hepatocytes
what is the endothelium of the sinuoid like
fenerstrated
why is this important
liquid components of blood have free access to the hepatocytes but blood cells DO NOT
what can be seen in the hepatocyte cytoplasm
mitchondria with tubular cirstae
free ribosomes
RER
Golgi complexes cluster close to the bile canilicusus
SER
glycogen and lipid stroage
what does the SER contain
detofication enzymes
what is in glycogen and lipids
lysomes and peroisomes
what is the parenchyma supported by
reticular fibres (type III)
Type I
where are type I colalgne fibres found
space of Disse
what does this meshwork support
hepatocytes and sinusoidal lining cells
what does the rectiulin do
The reticulin merges with the sparse collagenous supporting tissue of the portal tract T and central venule V.
at the periphery of the liver what is the reticulin continuous with
liver capsule
what are the portal tracts accompanied by (2)
liver capsule
collagenous connective tissue
What are Kupffer cells
stellate marcophages
what are the kupffer found between
the sinusoidal endothelial cells on the lumane surface within sinsuoids near the portal areas
what is the main function of kupffer cells
break down aged erythrocytes and free heme for reuse
remove bacteria and debris that may enter the portal blood
adaptive immunity
hepatic steallate fate storing cells
contain vitamin A
what is their function
stores vitamin a
produce ECM
local immunity
transform myofibroblasts to produce scar tissue in the liver
what does the kupffer cell have
lysome and a irregular micovilli
what is bile
what does it contain
alkaine solution
water ions phsopipids bilibruin and bile salts
why are bile salts inmportant
emulsification of fats
primary bile is produced by what
hepatocytes
what is the bile modified by
cholagnicotyeswh
where are the cholagniocytes found
lining the biliary tree
what is the bile secreted into
canilculi
what is the canilui formed bu
fine channels formed by plasma membrane of adjacent hepatocytes
what do the bile caniluiof adjacent hepatocytes plate merge to form
canals of herig
what do the canal herig drain into
the bile ducutles of the portal tracts
what are small bile ducts made of ep
The smallest intrahepatic bile ducts have one layer of small cuboidal cells
where are ducts always found
portal tracts and travel to with branches to the portal veins or hepatic arteries
what is the direction of the bile
from the centrle of the lobules to the periphery Not from the central vein
Intrahepatic biliary system - bc
bile canailcui with small channels formed by tight junctions
no membrane limited by plasma but have tight junctions
near the peripheral portal areas what does bile canacuili do
empty into the canal of hering
then into what
bile ductules
what is the bile ductules composed of
cholangiocytes (cubodial epithelium cells)
where do the bilte ductules end
in the bile ducts in the portal spaces
what happens to the cells as the ducts get larger
more olumnar
what happens to their nculei
more basal
what is the connective tissue
dense collagen fibre bundles surrounds the ducts
what do the bile ducts fusing form
hepatic ducts
