Download the portal vein

ANATOMY OF HEPATOBILIARY
HEPAR
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The largest gland of the body
location
function
lobation
segmen
attachment
counter current flow
vessel: porta-systemic anastomosis
Introduction
The liver
• The liver is a pinkish-brown (In life it is
reddish brown in) colour
• an overall wedge shape "boomerang
shaped" organ in the human body
• is the largest solid organ (the largest of
all is the skin)
• Is the largest gland in the human body
• In an adult it weighs typically about 2%
of body mass (70kg). 1.6 kilograms (3½
pounds)
• is about 18 cm (7 inches) across and 15
cm (6 inches) deep at its deepest part -- range : 6-12 cm in percussion at right
mic line
• medical terms to do with the liver
often start in hepato- or hepatic from
the Greek hepar for liver.
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Several functions
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Formation of bile
When the red cells of the blood become worn out
they are destroyed by the cells of the
reticuloendothelial system
In this process bilirubin is formed, and this is
carried by the blood to the liver. Together with
several other substances it is secreted by the liver
as bile.
The circulation of blood in the liver is so
arranged that very large volumes of blood
come into close contact with the cells of the
lobules.
The cells are thus in a favorable position both
to absorb materials from the blood and also
secret materials into it.
This they do all the time, for the real task of
the liver is to maintain in the blood the
correct concentrations of many of its
constituents.
Hepatocytes carry out most of the tasks
attributed to the liver, but the phagocytic
Kupffer cells that line the sinusoids are
responsible for cleansing the blood
Gall bladder
Vesica fellea
• A pear-shaped organ, 7 to
10 cm long, capacity 3050 ml
• lies just below the right
lobe of the liver in a
hollow under the liver
• is attached to the visceral
surface of the liver by the
cystic duct.
• The main function of the
gall bladder is to store the
bile that is secreted by the
liver,and is concentrated
by the reabsorption of
water from it.
• the bile travels to the gall
bladder along the
common hepatic duct
• When fatty food is digested, the gall
bladder contracts, under the action
of the hormone cholecystokinin,
thus delivering bile through the
common bile ducts (choledochus)
to the small intestine where it is
able to help dissolve fats
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The bile duct and the pancreatic
duct enter it together on its
posteromedial surface a little below
middle of part 2 of duodenum
(descendens part) at papilla
duodeni major (ampula
hepatopancreatica Vatteri.
The most common disorder of the
gall bladder is gallstones
(cholelithiasis), which are
composed of cholesterol crystals or
pigment material
topography
• The liver lies in the upper right part of the abdominal cavity.
• It occupies most of the right hypochondrium and epigastrium,
although it frequently extends into the left hypochondrium as
far as the left lateral line.
• The narrow end of the wedge lies towards the left
hypochondrium, with the anterior edge pointing anteriorly
and inferiorly.
• The superior and right lateral aspects are shaped by the
anterolateral abdominal and chest wall as well as the
diaphragm.
• The inferior aspect is shaped by the adjacent viscera.
• and although firm and pliant its weight and texture depend in
part on the volume of venous blood it contains.
Anatomy of the
Liver
• The liver is situated mostly in the
top right portion of the
abdominal cavity just under the
diaphragm.
• It can be felt as a hardish mass
just below the bottom right rib.
liver projection to the anterior Abdomen wall
Liver ligaments
• It is connected to the diaphragm and
abdominal walls by five ligaments: the
membranous falciform (which also separates
the right and left lobes), coronary, right and
left triangular ligaments, and the fibrous
round (teres) ligament (which is derived from
the embryonic umbilical vein).
HEPATIC LOBATION
Anatomis (4lobus)
Right lobe (terbesar)
Left lobe
Quadrate lobe (lig. Teres hepatis dan veseca
fellea)
Caudate lobe (Vena cava inferior, lig. Venosum,
dan porta hepatis)
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The liver is divided by the 'principal plane' into two halves of approximately equal size.
The principal plane is defined by an imaginary parasagittal line from the gallbladder anteriorly to the
inferior vena cava posteriorly.
The usual functional division of the liver into right and left lobes lies along this plane.
The liver is further subdivided into segments, each supplied by a principal branch of the hepatic artery,
portal vein and bile duct.
Segments I, II, III and IV make up the functional left lobe, and segments V, VI, VII and VIII make up the
functional right lobe.
The right lobe can be further divided into a posterior and anterior section or sector.
The right posterior section is made up of segments VI and VII, and the right anterior section is made up of
segments V and VIII.
The left lobe can also be divided into sections: segment IV is referred to as the left medial section, and
segments II and III as the left lateral section.
The hepatic veins lie in liver parenchyma between the sections.
Segment I corresponds to the gross anatomical caudate lobe and segment IV to the quadrate lobe.
surgical 8 segments
(cabang, v hepatica, vena porta (Couinad)a. Hepatica,drainase
biliaris (Healey and Schroy)
SEGMENTS IN LIVER
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I
II
III
IVa
IVb
V
VI
VII
VIII
caudate / spigel lobe
left posterolateral segment
left anterolateral segment
left superomedial segment
left inferomedial segment
right anteroinferior segment
right posteroinferior segment
right posterosuperior segment
Right anterosuperior segment
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Segmentation of the liver - Couinaud.
The segments are sometimes referred to by name –
I, caudate (sometimes subdivided into left and right parts);
II, lateral superior;
III, lateral inferior;
IV, medial (sometimes subdivided into superior and inferior parts);
V, anterior inferior;
VI, posterior inferior;
VII, posterior superior;
VIII, anterior superior.
Although a variety of definitions have been used to describe the anatomy of the liver
segments, the most widely accepted clinical nomenclature is that described by Couinaud
(1957), and Healey and Schroy (1953).
The internal architecture of the liver is divided into segments, commonly referred to as
Couinaud's segments. Couinaud based his work on the distribution of the portal and hepatic
veins whilst Healey and Schroy studied the arterial and biliary anatomy.
HEPATIC VESSELS
• The vessels connected with the
liver are:
– The portal vein
– The hepatic artery proper
– The hepatic veins
vascularisation
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Liver Blood flow
• The liver receives blood from two sources.
• Oxygenated blood is supplied in the hepatic artery, a branch of the celiac
trunk from the abdominal aorta.
• Venous blood from the entire gastrointestinal tract (containing nutrients
from the intestines) is brought to the liver by the hepatic portal vein.
On reaching the liver the portal vein divides into thousands of which pass
in between the lobules and terminate in the sinusoids.
The blood leaves the liver via a central vein in each lobule, which drains in
the hepatic vein.
The central canal is a blood vessel in the middle of each lobule which
receives blood from the hepatic portal vein and hepatic artery via the
sinusoids and drains the blood into the hepatic vein
Truncus celiacus
Truncus coeliacus
HEPATIC ARTERY &
ITS BRANCHES
• Divide and subdivide in the liver
• Smaller rami being associated with
those of the portal vein with which
they are distributed
• There are NO ANASTOMOSIS between
their territories; each is END-ARTERIES
HEPATIC ARTERY &
ITS BRANCHES
• A blood vessel which supplies the
liver with oxygenated blood
• Supplies 20% of the liver’s blood
Truncus celiacus
dipercacabangkan
aorta abdominalis
(V.TH 12),
mempercabangkan
a. gastrica sinistra,
a. hepatica communis
dan
a.lienalis.
a.hepatica communis
datang di cranial pars superior
duodeni,
bercabang
a. gastrica dextra (ke curvature
minor),
a.
hepatica propria (ke porta
hepatica, rr. Dexter, rr
sinister dan a. cystica) dan
a. pancreaticuduodenalis
(yang bercabang menjadi
a.
pancreaticoduodenalis
superior dan
a. gastroepiploica dextra, ke
curvatura major, oral,
beranastomosis dengan a.
gastroepiploica sinistra
HEPATIC VEINS
• Convey the blood from the liver to
inferior vena cava
• Have a thin tunica adventitia;
binding them to the wall of their
canals within the liver
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THE PORTAL VEIN
• Supplying most of the blood to
the liver (supplies 80% of the liver’s
blood)
• Formed posterior to the neck of pancreas
by the union of
– The superior mesenteric vein
– The splenic vein
THE PORTAL VEIN
• The main channel of the portal system of
veins
• Collects blood from
the abdominal part of the GI tract
The gallbladder
The pancreas
The spleen
Vena porta hepatis
THE PORTAL VEIN
• At the right end of the porta hepatis,
the portal vein terminates by
dividing into right and left branches,
each of which supplies about half of
the liver
Portocava anastomosis
ZONES
• ZONE 1
– Immediately surrounding the portal triad
– The first to get exposed to toxins from portal
blood
• ZONE 2
• ZONE 3
– Closest to terminal hepatic venule
– Gets the least oxygenated blood
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CELLS OF THE LIVER
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Hepatocyte
Perisinusoidal (Ito) cells
Endotheliocytes
Macrophages (Kupffer cells)
Lymphocytes (pit cells)
The cells of biliary tree (cuboideal to columnar
epitheliocytes
• Connective tissue cells of capsule and portal tracts
PORTAL TRIAD
• CONSIST OF :
– BILE DUCT
– HEPATIC ARTERIOLE
– PORTAL VENULE, the largest structure
(histologically) in the triad
COUNTERCURRENT FLOW
• BLOOD-FLOW
• BILE-FLOW
BLOOD-FLOW
• Portal vein
portal triad
portal
venule
terminal hepatic venule
central venule
central vein
hepatic vein
• Zona 1
zona 3
BLOOD-FLOW
• Hepatocytes closest to portal triad
– receive the most oxygenated blood
– Specialized for drug detoxification
– most susceptible to damage from drug
toxicity
BLOOD-FLOW
• Hepatocyte closest to the terminal hepatic
venule
– Receive the least oxygenated blood
– Specialized for bile production
– Most susceptible to damage in the event of
hypoxia
BILE - FLOW
• Central venule
bile duct
hepatic duct
bile canaliculus
portal triad
common bile duct
• Zona 3
zona 1
PORTAL - SYSTEMIC ANASTOMOSIS
• The portal venous system communicates with
the systemic venous system
• Important clinically
• Portal circulation obstructed, blood from GI
tract can still reach the right side of the heart
through IVC via collateral routes
Vena porta hepatis
PORTAL SYSTEMIC ANASTOMOSIS
• The portal veins and its tributaries have no valves
• In portal hypertension
– Venous pressure in portal venous system increased
– Blood in portal venous may reverse its direction
– Blood pass through portal-systemic anastomosis into the
systemic venous system
– Causes the vein in portal-systemic anastomosis areas to
dilate and tortuous and called varicose vein
PORTAL - SYSTEMIC ANASTOMOSIS
AREA
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In the gastroesophageal region
In the anorectal region
In the paraumbilical region
In the retroperitoneal region
PORTAL - SYSTEMIC ANASTOMOSIS
AREA
• Esophageal tributaries of the left gastric
vein anastomose with the esophageal
veins, which empty into the azygos vein
• The superior rectal veins anastomoses with
the middle and inferior rectal veins, which
are tributaries of the internal iliac and
internal pudendal veins, respectively
PORTAL - SYSTEMIC ANASTOMOSIS
AREA
• The paraumbilical veins in the
falciform ligament anastomose with
subcutaneous veins in the anterior
abdominal wall
• Tributaries of the splenic and
pancreatic veins anastomose with the
left renal vein
VARICOSE VEIN
• Anal region are called hemorrhoids
• Gastroesophageal  esophageal varices
• Paraumbilical  caput medusae
– Like small snake under the skin
– Its resemblance to the serpents on the head of
Medusa, a character in Greek mythology
Common way to reducing portal
pressure
• Portocaval anastomosis
– Creating a communications between the portal
vein and the inferior vena cava
• Splenorenal anastomosis
– Join the splenic vein to the left renal vein,
following removal of the spleen (splenectomy)
PORTAL HYPERTENSION
• In the normal system, blood is delivered to the
liver via :
– The hepatic artery (400 ml/minute)
– The portal vein (1000 ml/minute)
• Normally, blood from all of the gastrointestinal
organs come through
the liver to be processed
PORTAL HYPERTENSION
• In the portal hypertension, there is a medical
blockage in the liver, due to :
– Cirrhosis
– Scarring
– Hepatitis
– Sarcoidosis
PORTAL HYPERTENSION
• This blockage causes :
– the incoming low pressure blood to ‘back
up’
• because the blood does not have the
pressure to overcome the elevated
pressure in the portal vein
PORTAL HYPERTENSION
• The result is distended veins throughout the
GI system :
– Hemorrhoid
– Varices
– Caput medusae
– Leakage of fluid into the peritoneum
• Ascites
• Edema
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Ascites
• from Greek askites,
"baglike“)
• is a gastroenterological
term for an accumulation of
fluid in the peritoneal
cavity.
• The medical condition is
also known as peritoneal
cavity fluid, peritoneal fluid
excess, hydroperitoneum
or more archaically as
abdominal dropsy
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lobulus
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