00:01
So in a review, this diagram just
summarizes the structure of the hepatocyte.
00:07
Be very careful and very sure that you
can identify the different borders,
the bile canaliculi and the space of
Disse, and identify the enormous factory
inside the hepatocyte, and the details of
the sinusoids and the microvillus projections
of the hepatocyte into the space of Disse
and the fenestrated endothelium
letting fluid leaking to that space. And
also, the macrophage, the Kupffer cell
that sits in the endothelial lining an
acts as a phagocyte, and also it has other
functions. So this is a good summary
slide of the function of the
hepatocyte and of its relationship to
adjacent hepatocytes and also the
sinusoids. And I show this slide just to
try and summarize the blood flow,
first of all, to the liver, and then the
flow of the bile from the liver into the
gall bladder. If you focus on the
right-hand component, the right-hand side
of the diagram where there's a very
small lobe of the liver, and look at the
labels 1 and 2, it does illustrate
one part of the blood
supply to the liver that's important.
Portal vein carries blood from the intestine.
01:36
It goes into the liver, as you see
here, and branches into a number
of interlobar and interlobular veins.
And they eventually find their way to
the corners of these portal triads where
they branches at the portal vein.
01:54
And that blood pours towards the central
vein, the contents get processed by the
hepatocytes, the hepatocytes return some
components to the blood, and the blood,
when it drains to that central vein,
then passes out of the liver
through the inferior vena cava back to
the heart, and then to circulate around
the body. On the left-hand side, on the
larger lobe, it illustrates two things, the
arterial supply to the liver and the
duct or the hepatic duct and the bile
duct drainage from the liver.
02:32
First of all, look at the hepatic artery.
It supplies blood, oxygenated blood to the
liver, and then branches to form that
branch to the hepatic artery that is going
to join the venous blood coming from the
portal vein, and circulate into that
central vein past the hepatocytes and
supply them with oxygen. Now, focus on the green
structures. They are the bile ducts, the
bile canaliculi carried by or made by
the hepatocyte back to the edges of the
portal triads, and then they eventually find
their way into the hepatic ducts. And a
number of ducts follow and are named according
to their locations. And finally, the bile
goes and gets stored in the
gall bladder, where it's stored,
concentrated, and then released through
the common bile duct into the duodenum.
Notice on this slide also that there is
a pancreatic duct, also going
into the common bile duct,
also enabling the pancreas to deliver
its exocrine secretions, digestive
enzymes through that duct into the
duodenum.