biliary system

1. FUNCTIONALANATOMY
AND PHYSIOLOGY: LIVER
AND BILIARY SYSTEM
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DR.MEGHA SHUKLA
MD SCHOLAR
PG DEPARTMENT OF
KRIYA SHARIR,DSRRAU.
JODHPUR
DR.DEEPAK VERMA
ASSISTANT PROFESSOR
DAC

2. INTRODUCTION ABOUT LIVER
The liver is the largest gland in the body and has a wide variety of
functions . It is exocrine(bile) & endocrine organ(Albumen ,
prothrombin & fibrinogen) .
Location:
Right hypochondrium + Epigastrium & extends to left hypochondrium
Weight:
1/50 of body weight in adult & 1/20 of body weight in infant
FUNCTIONS OF THE LIVER
•Secretion of bile & bile salt
•Metabolism of carbohydrate, fat and protein
•Formation of heparin & anticoagulant substances
•Detoxication
•Storage of glycogen and vitamins
•Activation of vita .D
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3. WHAT IS FUNCTIONAL ANATOMY
• Definition
(noun) the study of anatomy in its relation to
function
• Synonyms : morphophysiology , physiological
anatomy
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4. Functional Anatomy of Liver
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5. INTRODUCTION
The liver is an accessory digestive organ that produces bile, a fluid containing
cholesterol and bile acids, and an alkaline compound which helps the breakdown of
fat. Bile aids in digestion via the emulsification of lipids. The gallbladder, a small
pouch that sits just under the liver, stores bile produced by the liver which is
afterwards moved to the small intestine to complete digestion. The liver's highly
specialized tissue consisting of mostly hepatocytes regulates a wide variety of
high-volume biochemical reactions, including the synthesis and breakdown of small
and complex molecules, many of which are necessary for normal vital
functions. Estimates regarding the organ's total number of functions vary, but
textbooks generally cite it being around 500.
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6. STRUCTURE
• The liver is a reddish-brown, wedge-shaped organ with four lobes of
unequal size and shape. A human liver normally weighs approximately
1.5 kg (3.3 lb), and has a width of about 15 cm (6 in).There is also
considerable size variation between individuals, with the standard reference
range for men being 970–1,860 g (2.14–4.10 lb) and for women 600–
1,770 g (1.32–3.90 lb). It is both the heaviest internal organ and the
largest gland in the human body.
• Lobules are the functional units of the liver. Each lobule is made up of
millions of hepatic cells (hepatocytes), which are the basic metabolic cells.
The lobules are held together by a fine, dense, irregular, fibroelastic
connective tissue layer extending from the fibrous capsule covering the
entire liver known as Glisson's capsule. This extends into the structure of
the liver, by accompanying the blood vessels (veins and arteries), ducts,
and nerves at the hepatic hilum. The whole surface of the liver except for
the bare area, is covered in a serous coat derived from the peritoneum, and
this firmly adheres to the inner Glisson's capsule.
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7. Cells Of The Liver
Cells of the liver include
 Hepatocytes,
 Hepatic stellate cells -
also known as
perisinusoidal lipocytes,
or ito cells - sinusoidal
endothelial cells,
 Macrophages (kupffer
cells),
 The cells of the biliary
tree - Cuboidal to
columnar epithelium -
and
 Connective tissue cells of
the capsule and portal
tracts.
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8. Hepatocytes
• Hepatocytes represent 60 % of the liver‘s cells and about 80 %
of the liver‘s total cell mass. Most of the liver‘s synthetic and
metabolic capabilities stem from the work of hepatocytes .
Hepatocytes are arranged in plates only a single cell thick .
• The main function of hepatocytes is to participate in lipid,
carbohydrate and protein metabolism. They also produce serum
proteins such as albumin and coagulation factors.
• Furthermore, hepatocytes produce and secrete bile as well as
detoxify and excrete cholesterol, steroid hormones and xenobiotic
drugs. Numerous xenobiotics are metabolized by the mixed-
functions of monooxidases found in hepatocytes.
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9. Endothelial Cells
• The sinusoidal endothelial cells line the walls
of the hepatic sinusoid and perform a function
of filtration due to the presence of fenestrae.
• They may also function as antigen presenting
cells and secrete certain cytokines and
eicosanoids.
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10. Stellate Cells
• They are located in the space of Disse
(between hepatocytes and sinusoid) and generally
protrude to come into contact with several
sinusoids .
• The liver plays a central role in uptake and
storage of vitamins A (Retinol) and stores about
95 % of retinoids found in the body. The fat
storing perisinusoidal cells of the liver, stellate
cells are the main vitamin A storing cells.
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11. Kupffer Cells
• They are located within the sinusoid and are in constant
contact with gut-derived particles that lead to low but
constant amount of activation of these monocyte derived
cells. Upon activation they are able to secrete a vast range
of inflammatory mediators such as cytokines, reactive
oxygen species, eicosanoids and nitric oxide
• The liver harbors large amounts of kupffer cells, which
represent the largest tissue resident macrophage population
of the body
• Kupffer cells have receptors that enable them to bind cells
covered with immunoglobulins or bind to complement
receptors and subsequently phagocytose cell
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12. HISTOLOGY
Two major types of liver cell: Parenchymal cells and
non parenchymal cells. About 70–85% of the liver
volume is occupied by parenchymal hepatocytes. Non
parenchymal cells constitute 40% of the total number of
liver cells but only 6.5% of its volume. The liver
sinusoids are lined with two types of cell, sinusoidal
endothelial cells, and phagocytic Kupffer cells. Hepatic
stellate cells are non parenchymal cells found in
the perisinusoidal space, between a sinusoid and a
hepatocyte. Additionally, intrahepatic lymphocytes are
often present in the sinusoidal lumen.
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14.  Microscopically, each liver lobe is seen to be made up of hepatic
lobules. The lobules are roughly hexagonal and consist of plates
of hepatocytes radiating from a central vein.
 In the mature liver, hepatocytes are arranged mainly in plates - or
cords, Between the plates are venous sinusoids, which
anastomose with each other via gaps in the hepatocyte plates.
 Bile secreted by the hepatocytes is collected in a network of
minute tubes (canaliculi).
 The central vein joins to the hepatic vein to carry blood out from
the liver. A distinctive component of a lobule is the portal triad,
which can be found running along each of the lobule's corners.
The portal triad, misleadingly named, consists of five structures:
a branch of the hepatic artery, a branch of the hepatic portal vein,
and a bile duct, as well as lymphatic vessels and a branch of the
vagus nerve.Between the hepatocyte plates are liver sinusoids,
which are enlarged capillaries through which blood from the
hepatic portal vein and hepatic artery enters via the portal triads,
then drains to the central vein.
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15. FUNCTIONALANATOMY
• The central area or hepatic hilum, includes the opening known as the porta hepatis which carries
the common bile duct and common hepatic artery, and the opening for the portal vein. The duct, vein, and
artery divide into left and right branches, and the areas of the liver supplied by these branches constitute
the functional left and right lobes. The functional lobes are separated by the imaginary plane, Cantlie's
line, joining the gallbladder fossa to the inferior vena cava. The plane separates the liver into the true
right and left lobes. The middle hepatic vein also demarcates the true right and left lobes. The right lobe
is further divided into an anterior and posterior segment by the right hepatic vein. The left lobe is divided
into the medial and lateral segments by the left hepatic vein.
• The hilum of the liver is described in terms of three plates that contain the bile ducts and blood vessels.
The contents of the whole plate system are surrounded by a sheath.The three plates are the hilar plate,
the cystic plate and the umbilical plate and the plate system is the site of the many anatomical variations
to be found in the liver.4/11/2020 15

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17. SURFACES OF THE LIVER,
THEIR RELATIONS &
IMPRESSIONS
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18. The liver is the largest organ in the body. Its
domed upper surface relates entirely to the
diaphragm while its postero-inferior, or visceral,
surface rests against the abdominal oesophagus,
stomach, upper duodenum, hepatic flexure of the
colon, right kidney and suprarenal gland, as well
as carrying the gall bladder. Its surface relations
can be marked out by joining points on: the right
costal margin in the mid-axillary line, (the 10th
rib) the right 5th intercostal space ditto the left 5th
intercostal space in the mid-clavicular line.
POSITION
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19. SURFACES OF LIVER
•Postero - Inferior Surface= Visceral Surface
•Superior Surface = Diaphragmatic Surface
•Anterior Surface
•Posterior Surface
•Right Surface
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21. Lobes of the liver
•Rt. Lobe
•Lt .lobe
•Quadrate lobe
•Caudate lobe
Rt. & Lt lobe separated by
• Falciform ligament
•Ligamentum Venoosum
•Ligamentum teres
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22. Relations of the liver Anteriorly
•Diaphragm
•Rt & Lt pleura and lung
•Costal cartilage
•Xiphoid process
•Ant. abdominal wall
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24. Portal Triad
Branches of portal vein,
hepatic artery and the biliary
ducts bound together in the
perivascular fibrous capsule.
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25. Blood Flow Distribution
Total human liver blood flow represents approximately 25% of the cardiac output,
up to 1500 ml/min. Hepatic °ow is subdivided in 25-30% for the hepatic artery (500
ml/min) and the major part for the portal vein (1000 ml/min). Assuming a human
liver weighs 1500 g, total liver flow is 100 ml/min per 100 g liver. Comparing this
normalized °ow rate to other species, it can be concluded that total liver blood flow
is 100-130 ml/min per 100 g liver, independent of the species. The ratio of
arterial:portal blood °ow, however, is species-dependent. The hepatic artery orig-
inates directly from the descending aorta, and is therefore saturated with oxygen.It
accounts for 65% of total oxygen supply to the liver. The hepatic artery also plays
an important role in liver blood vessel wall and connective tissue perfusion.It also
secures bile duct integrity. The blood from the portal vein is full of nutrients derived
from the intestine and allows the hepatocytes to perform their tasks. Blood from the
hepatic artery and the portal vein joins in the sinusoids.
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26. Blood supply
There are 2
distinct sources
that supply blood
to the liver:
• Oxygenated
blood flows in
from the hepatic
artery.
• Nutrient-rich
blood flows in
from the hepatic
portal vein.
Almost all blood that enters the liver via the
portal tract originates from the gas-trointestinal
tract as well as from the spleen, pancreas and
gallbladder. A second blood supply to the liver
comes from the hepatic artery, branching directly
from the celiac trunc and descending aorta. The
portal vein supplies venous blood under low
pressure conditions to the liver, while the hepatic
artery supplies high-pressured arterial blood.
Since the capillary bed of the gastrointestinal
tract already extracts most O2, portal venous
blood has a low O2 content. Blood from the
hepatic artery on the other hand, originates
directly from the aorta and is, therefore,
saturated with O2. Blood from both vessels joins
in the capillary bed of the liver and leaves
via central veins to the inferior caval vein.
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27. 4/11/2020 27

28. Biliary system
• The biliary system consists of the organs and
ducts (bile ducts, gallbladder, and associated
structures) that are involved in the production and
transportation of bile.
The transportation of bile follows this sequence:
When the liver cells secrete bile, it is collected by a system of ducts that flow from the
liver through the right and left hepatic ducts.
These ducts ultimately drain into the common hepatic duct.
The common hepatic duct then joins with the cystic duct from the gallbladder to form
the common bile duct. This runs from the liver to the duodenum (the first section of the
small intestine).
However, not all bile runs directly into the duodenum. About 50% of the bile
produced by the liver is first stored in the gallbladder. This is a pear-shaped organ
located directly below the liver.
Then, when food is eaten, the gallbladder contracts and releases stored bile into the
duodenum to help break down the fats.
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29. Functions of the biliary system
The biliary system's main function includes the
following:
• To drain waste products from the liver into the
duodenum
• To help in digestion with the controlled release
of bile
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30. Bile
 About 500 mL is secreted per day.
 Some of the components of the bile are reabsorbed in
the intestine and then excreted again by the liver
(enterohepatic circulation).
 The glucuronides of the bile pigments, bilirubin and
biliverdin, are responsible for the golden yellow color
of bile.
 The bile salts are sodium and potassium salts of bile
acids, and all those secreted into the bile are conjugated
to glycine or taurine, a derivative of cysteine.
 The bile acids are synthesized from cholesterol.
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31. CBD
Extra hepatic biliary system
Rt. hepatic duct
+
Lt hepatic duct
↓
Common hepatic duct
+
Cystic duct
↓
Common bile duct
- 4cm
- Descend in free edge of lesser
omentum
- Supra duodenal part
Retro duodenal part
Retro pancreatic part
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32. Composition of Human Hepatic Duct
Bile
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33. Bile acids
 Primary bile acids
Formed in the liver are cholic acid and
chenodeoxycholic acid.
 Secondary bile acids
In the colon, bacteria convert cholic acid to
deoxycholic acid and chenodeoxycholic acid
to lithocholic acid.
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34. • The acid-dependent fraction and the acid-
independent fraction. Hepatocytes secrete
• The bile acid-dependent fraction of the bile. This
fraction consists of bile acids, cholesterol, lecithin
(a phospholipid), and bilirubin (a bile pigment).
The bile acid-independent fraction of the bile,
which is secreted by the hepatocytes and
epithelial cells of the bile canaliculi, is a
bicarbonate-rich aqueous fluid that gives bile its
alkaline pH.
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35. BILE SALTS
• Bile salts are conjugated in the liver from primary and
secondary bile acids. The primary bile acids are cholic acid and
chenodeoxycholic (chenic) acid. These acids are synthesized from
cholesterol by the hepatocytes. The secondary bile acids are
deoxycholic acid and lithocholic acid. These acids are formed in the
small intestine by the action of intestinal bacteria, after which they
are absorbed and flow to the liver.
• Both forms of bile acids are conjugated with
amino acids in the liver to form bile salts.
• Conjugation makes the bile acids more water
soluble, thus restricting their diffusion from the
duodenum and ileum.
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36. • The liver also has hemostatic functions. It
synthesizes prothrombin, fibrinogen, and
clotting factors. Vitamin K, a fat-soluble
vitamin, is essential for the synthesis of other
clotting factors. Because bile salts are needed
for reabsorption of fats, vitamin K absorption
depends on adequate bile production in the
liver.
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37. Comparison of Human Hepatic Duct Bile and
Gallbladder Bile.
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38. Major functions of liver
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39. Thank you
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