Transcript Liver& biliary

Liver
It is the largest gland in the body. Its functions are production of bile pigments from the
hemoglobin of worn-out red blood corpuscles and secretes bile salts these together are
conveyed to the duodenum by the biliary ducts. Also, it synthesizes heparin
It is a soft & pliable and occupies the upper part of the abdominal cavity just beneath the
diaphragm. Its greater part is situated under cover of the right costal margin and right
hemidiaphragm separates it from the pleura; lungs; pericardium and heart. It extends to the
left hemidiaphragm.
The convex upper surface is molded to the undersurface of the dome of the diaphragm.
It has 4 surfaces ( anterior, posterior, superior and inferior ); base ( right surface ) which is
directed to the right and an apex which is directed to the left.
1
fundus
stomach
cudate
Bare area
2
Lesser omentum
Pylorus
2nd
duodenal
Renal
Transverse colon
R.
R
Colic
The posteroinferior or visceral surface is irregular in shape. It lies in contact with the
abdominal part of the esophagus (1 ); stomach; duodenum; right colic flexure; right kidney;
suprarenal gland ( 2 ) and the gallbladder. The porta hepatis ( hilum of the liver ) lies on this
surface. It lies between the caudate & quadrate lobes.
The right lobe is divided into a quadrate lobe and a caudate lobe by the presence of the
gallbladder; the inferior vena cava; the fissure for the ligamentum teres; and the fissure for
the ligamentum venosum. These 2 fissures meet each other at the left end of porta hepatis.
Functionally, the caudate & quadrate lobe are parts of the left lobe.
N.B. the caudate lobe lies above opening of lesser sac ( tuber omentale ) and in front of the
superior recess of the lesser sac.
The liver is divided into right & left
lobe by the attachment of the
peritoneum of the falciform ligament.
The liver is completely surrounded by
a fibrous capsule but only partially
covered by peritoneum. The bare area;
fossa for gall bladder; fossa for inferior
vena cava and lines of attachment of
various ligaments not covered with
peritonum.
The liver is made up of liver lobules.
The central vein of each lobule is a
tributary of the hepatic veins.
In the spaces between the lobules are
the portal canals which contains
branches of the hepatic artery ;
tributary of a bile duct and portal vein.
The arterial and venous blood passes
between the liver cells by means of
sinusoids and drains into the central
vein.
In the porta hepatis lie the right & left hepatic ducts; the right & left branches of
the hepatic artery; the portal vein and sympathetic & parasympathetic nerve fibers
and a few hepatic lymph nodes which drain the liver and gall bladder and send
their efferent vessels to the celiac lymph nodes.
The upper part of the edge of the lesser omentum is attached to the margin of the
porta hepatis.
Lesser omentum: It connects the
lesser curvature of the stomach &
duodenum to the fissure of the
ligamentum venosum and the porta
hepatis on the under-surface of the liver.
Its free border is formed where the 2
layers are continuous. It forms the
anterior boundary of the opening to
the lesser sac.
It contains along the lesser curvature
the right & left gastric vessels. At the
free border the hepatic artery & bile duct
anteriorly and portal vein posteriorly.
Falciform ligament
It is a sickle- shaped fold which connects the liver
to the diaphragm and anterior abdominal wall.
It has 3 borders
1- Convex border which is attached to the
diaphragm & anterior abdominal wall down to the
umbilicus in the median plane.
2- concave border which is attached to anterior
& upper surfaces of the liver between the right &
left lobes. On the upper surface of the liver the 2
layers of the ligament separate and the right one
joins the superior layer of the coronary ligament,
while the left layer joins the anterior layer of the
left triangular ligament.
3- Free border which extends from the
umbilicus to the notch for ligamentum teres at
the inferior border of the liver. It contains the
ligamentum teres ( obliterated left umbilical vein )
and paraumbilical veins.
At the free border , the 2 layers of the ligament
are continuous with each other.
Coronary ligament
It consists of 2 layers which enclose between them the bare area of the liver.
The superior layer connects the right lobe of the liver with the diaphragm and is
continuous medially with the right layer of the falciform ligament. It is continuous
laterally with the anterior layer of the right triangular ligament.
The inferior layer connects the right lobe of the liver either with the diaphragm or
right hepato-renal ligament. It is continuous laterally with the posterior layer of the
right triangular ligament. It is attached medially to the lower part of groove for IVC; right
margin & upper border of the caudate lobe of the liver. Its ends join posterior layer of
lesser omentum at the upper end of the fissure for ligamentum venosum.
Right triangular ligament
It connects the upper surface of the right lobe of the liver with the diaphragm.
Medially, Its anterior & posterior layers are continuous with superior & inferior layers of
coronary ligament.
Left triangular ligament
It connects the upper surface of the left lobe of the liver with the diaphragm.
Medially, Its anterior layer is continuous with the left layer of falciform ligament.
Its posterior layer joins anterior layer of lesser omentum at the upper end of the
fissure for ligamentum venosum.
N.B. The previous ligaments are called hepatophrenic ligaments.
Relations
Anteriorly:
Diaphragm; right & left costal margins; right and left pleura and lower margins of both
lungs; xiphoid process and anterior abdominal wall in the subcostal angle.
Posteriorly:
Diaphragm; right kidney; hepatic flexure of the colon; duodenum; gallbladder; inferior vena
cava; esophagus and fundus of the stomach.
The ligamentum teres passes into a
fissure on the visceral surface of the
liver and joins the left branch of the
portal vein in the porta hepatis.
The ligamentum venosum ( a fibrous
band that is a remains of the ductus
venosus ) is attached to the left branch
of the portal vein and ascends in a
fissure on the visceral surface of the
liver to be attached above to the inferior
vena cava.
In the fetus, oxygenated blood is
brought to the liver in the left umbilical
vein ( ligamentum teres ).
The greater proportion of the blood
bypasses the liver in the ductus
venosus ( ligamentum venosus ) and
joins the inferior vena cava.
At birth, the umbilical vein and ductus
venosus close and become fibrous cord
Blood Supply
The hepatic artery, a branch of the celiac artery, divided into right & left terminal
branches that enter the porta hepatis.
The portal vein divided into right & left terminal branches that enter the porta
hepatis behind the arteries.
The hepatic veins ( 3 or more ) emerges from the posterior surface of the liver
and drain into the inferior vena cava.
Blood Circulation through the Liver:
The blood vessels conveying blood to the liver are the hepatic artery ( 30% ) and
portal vein ( 70 % ). The hepatic artery brings oxygenated blood to the liver and
the portal vein brings venous blood rich in the products of digestion which have
been absorbed from the gastrointestinal tract.
The arterial and venous blood is conducted to the central veins drain into the right
& left hepatic veins and these leave the posterior surface of the liver and open
directly into the inferior vena cava.
Lymph Drainage
The liver produces large amount of lymphabout one third to one half of all body
lymph. The lymph vessels leave the liver
and enter several lymph nodes in the porta
hepatis.
The efferent vessels pass to the celiac
nodes. A few vessels pass from the bare
area of the liver through the diaphragm to
the posterior mediastinal lymph nodes.
Nerve Supply
Sympathetic and parasympathetic
nerves form the celiac plexus.
The anterior vagal trunk gives rise to a
large hepatic branch which pass
directly to the liver.
Clinical Notes
1- Liver Trauma:
It is a soft; friable structure enclosed in a fibrous capsule. Fractures of the
lower ribs or penetrating wounds of the thorax or upper abdomen are common
causes of liver injury. Blunt traumatic injuries from automobile accidents are
also common and severe hemorrhage accompanies tears of this organ.
The bile ducts; hepatic arteries and portal vein are distributed in a segmental
manner. So, appropriate ligation of these structures allows the surgeon to
remove large portions of the liver in patients with severe traumatic laceration
of the liver or with liver tumor. Even large localized carcinomatous metastatic
tumors have been successfully removed.
2- subphrenic Spaces:
An abnormal accumulation of gas or fluid is necessary for separation of
peritoneal surfaces. The anterior surface of the liver is normal dull on
percussion.
Perforation of a gastric ulcer is often accompanied by a loss of the liver
dullness caused by accumulation of gas over the anterior surface of the liver
Greater sac
It is the space which is exposed when the
anterior abdominal wall is cut.
It is divided by the greater omentum;
transverse colon and transverse mesocolon
1- Upper anterior part ( supracolic part )
above transverse colon.
2- lower posterior part ( infracolic part)
below transverse colon.
The 2 parts are continuous with each other at
the lateral borders of the greater omentum.
Supracolic compartment lies above the
transverse colon and below the diaphragm.
It is divided by hepatophrenic ligaments
(falciform ligament; coronary ligament and
right & left triangular ligaments ) into :
1- Right & left subphrenic recesses.
2- Hepatorenal recess between the
diaphragm and right kidney.
3Left subhepatic space ( omental bursa).
Subphrenic spaces
These are potential spaces only, and the
peritoneal surfaces are in contact.
The right & left anterior subphrenic spaces
lie between the diaphragm and the liver on
each side of the falciform ligament.
The right posterior subphrenic space lies
between the right lobe of the liver ; the right
kidney and the right colic flexure.
A patient with a subphrenic abscess or
collections of blood under the diaphragm may
complain of pain over the shoulder due to
irritation of the parietal diaphragmatic
peritoneum.
The skin of the shoulder is supplied by the
supraclavicualr nerves ( C3, C4 ).
To avoid the accumulation of infected fluid in
the subphrenic spaces and to allow this fluid
to gravitate downward into the pelvic cavity
where the rate of toxin absorption is slow. The
patient must sit up in bed with the back at an
angle of 45°.
Two extraperitoneal spaces in the subphrenic
region may become the site of localized
infection.
1- Right extraperitoneal space which lies
between the 2 layers of the coronary
ligament ( bare area ) of the liver and the
diaphragm.
2- Left extraperitoneal space which comprises
the extraperitoneal connective tissue
around the left suprarenal gland and the
upper pole of the left kidney.
The liver lies under cover of the
lower ribs and most of its bulk lies
on the right side. In infants, until
about the end of the 3rd year, the
lower margin of it extends 1 or 2
fingerbreadths below the costal
margin.
In adult who are obese or has a well
developed right rectus abdominis
muscle, the liver is not palpable.
In a thin adult, the lower edge of the
liver may be felt a fingerbreadth
below the costal margin. It is easily
felt when the patient inspires deeply
and the diaphragm contracts and
pushes down the liver.
The fundus of the gallbladder lies
opposite the tip of the 9th costal
cartilage. This area is where the
lateral edge of the right rectus
abdominis muscle crosses the
costal mergin.
Bile Ducts
Bile is secreted by the liver cells at a constant rate of about 40 ml per hour. The
bile is stored and concentrated in the gallbladder. Then ,it delivered to duodenum.
The bile ducts consists of the right & left hepatic ducts; common hepatic duct;
gallbladder; cystic duct and bile duct. The right hepatic duct drains the right lobe
of the liver and the left duct drains the left lobe ; caudate and quadrate lobes.
The right & left hepatic ducts emerge from the right & left lobes of the liver in the
porta hepatis. They unite after a short distance to form the common hepatic duct
which is about 1.5 inch (4 cm ) long. It descends within the free margin of the
lesser omentum. It is joined on the right side by the cystic duct from the
gallbladder to form the bile duct.
Cystic duct
It is about 1.5 ( 3.8 cm ) long and
connects the neck of the
gallbladder to the common hepatic
duct to form the bile duct.
It is usually S shaped and descends
in the right free margin of the lesser
omentum.
The mucous membrane of the
cystic duct is raised to form a spiral
fold that is continuous with a
similar fold in the neck of the
gallbladder. These folds is called
spiral valves which keep the lumen
constantly open.
Common Bile Duct
It is about 3 inch ( 8 cm ) long. In first part of its course , it lies in the right free
margin of the lesser omentum in front of the opening into the lesser sac. Here , it
lies in front of the right margin of the portal vein and on the right side of the
hepatic artery.
In the second part of its course, it is situated behind the 1st part of the duodenum
to the right of the gastroduodenal artery.
In the third part of its course , it lies in a groove on the posterior surface of the
head of the pancreas. Here , the bile duct comes into contact with the main
pancreatic duct.
The bile duct ends below by piercing
the medial wall of the 2nd part of
duodenum about halfway down its
length.
It is joined by the main pancreatic duct
and together they open into a small
ampulla in the duodenal wall called the
hepatopancreatic ampulla ( ampulla of
Vater). This ampulla opens into the
lumen of the duodenum by means of a
small papilla ( the major duodenal
papilla ).
The terminal parts of both ducts and the
ampulla are surrounded by circular
muscle ( smooth ) known as the
sphincter of the hepatopancreatic
ampilla ( sphincter of Oddi)
Occasionally, the bile and pancreatic
ducts open separately into the
duodenum.
Gallbladder
It is a pear shaped sac lying on the undersurface of the liver. It has a capacity of 30 to 50 ml
and stores bile which it concentrates by absorbing water.
It is divided into fundus; body and neck.
The fundus is rounded and projects below the inferior margin of the liver where it comes in
contact with the anterior abdominal wall.
The body lies in contact with the visceral surface of the liver and is directed upward;
backward and to the left.
The neck becomes continuous with the cystic duct which turns into the lesser omentum to
join the right side of the common hepatic duct to form the bile duct.
Relations :
Anteriorly: The anterior abdominal wall and the inferior surface of the liver.
Posteriorly: The transverse colon and the 1st and 2nd parts of the duodenum.
The peritoneum completely surrounds the fundus of the gallbladder and binds the
body and the neck to the visceral surface of the liver.
Function of the Gallbladder
When digestion is not taking place, the sphincter of Oddi remains closed and bile
accumulate in the gallbladder which concentrates bile; stores bile; absorbs bile
salts; keeping the bile acid; excretes cholesterol and secretes mucus.
The mucous membrane is thrown into permanent folds that unite with each other
giving the surface a honeycombed appearance. The columnar cells lining the
surface have microvilli on their free surface.
Bile is delivered to the duodenum as a result of contraction and partial emptying
of the gallbladder. This mechanism is initiated by the entrance of fatty foods into
the duodenum.
The fat causes release of the hormone cholecystokinin from the mucous
membrane of the duodenum. The hormone then enters the blood causing the
gallbladder to contract. At the same time the, the smooth muscle around the distal
end of the bile duct and the ampulla is relaxed , thus allowing the passage of
concentrated bile into the duodenum.
The bile salts in the bile are important in emulsifying fat in the intestine and
assisting with its digestion and absorption.
Blood Supply
The cystic artery which is a branch from the
right hepatic artery. It supplies the gallbladder.
The cystic vein drains directly into the portal
vein. Several small arteries & veins also run
between the liver and gallbladder.
Nerve Supply
Sympathetic & parasympathetic vagal fibers
form the celiac plexus. The gallbladder
contracts in response to the hormone
cholecystokinin which is produced by the
mucous membrane of the duodenum on the
arrival of fatty food from the stomach.
Lymph Drainage
It drains into a cystic lymph node situated near
the neck of the gallbladder. From this, the
lymph vessels pass to the hepatic nodes along
the course of the hepatic artery and then to the
celiac nodes.
Clinical Notes
1- Gallstones
They are usually asymptomatic. Also, they can give rise to gallbladder
colic or produce acute cholecystitis.
2- Acute Cholecystitis
It produces discomfort in the right upper quadrant or epigastrium.
Inflammation of the gallbladder may cause irritation of the
subdiaphragmatic parietal peritoneum which is supplied in part by the
phrenic nerve ( C 3,4 and 5 ) This may give rise to referred pain over
the shoulder because the skin in this area is supplied by the
supraclavicular nerves ( C 3 and 4 ).
3- Biliary Colic
It is usually caused by spasm of the smooth muscle of the wall of the
gallbladder to expel a gallstone. Afferent nerve fibers ascends
through the celiac plexus and the greater splanchnic nerves to the
thoracic segments of the spinal cord. Referred pain is felt in the right
upper quadrant or the epigastrium ( T 7; 8 and 9 dermatomes ).
Obstruction of the biliary ducts with a gallstone or by compression by
a tumor of the pancreas results in backup of bile in the ducts and
development of jaundice. The impaction of a stone in the ampulla of
Vater may result in the passage of infected bile into the pancreatic duct
producing pancreatitis.
Gallstones have been known to ulcerate through the gallbladder wall
into the transverse colon or the duodenum. They may passed naturally
per rectum. But, they may be held up at the ileocecal junction
producing intestinal obstruction.
4- Cholecystectomy & Arterial supply to Gallbladder
The pattern of arterial supply to gallbladder must be observed before
cholecystectomy operation. To avoid legation of the arteries with the common
hepatic duct or the main bile duct .
5- Gangrene of the gallbladder
It is rare because it is receives cystic artery from the right hepatic artery and also
small branches from the visceral surface of the liver.
Sonograms is used to demonstrate the gallbladder.