3. LIVER – PHYSIOLOGICAL
ANATOMY.
Largest gland
Wt – 1500 gm
Anatomically – lobes – 2
Right & left
Each part has blood
supply from hepatic
artery, portal vein & own
venous & biliary
drainage.
Tuesday, September 18, 2018
4. STRUCTURAL
CHARACTERISTICS
Structural & functional
units – hepatic lobules –
about 1 lac
Each lobules has hepatocytes
in columns
Between columns present
bile canaliculi
Hapatocytes tunneled by
blood sinusoids which drains
into central vein.
Tuesday, September 18, 2018
5. STRUCTURAL
CHARACTERISTICS
Sinusoids lined by
endothelial cells, along with
Kupffer cells in between.
At periphery of each lobule
present portal triad.
Contains – portal vein,
hepatic artery & bile duct.
Acinus – is structural unit of
liver.
Tuesday, September 18, 2018
6. ZONES OF ACINUS
Zone 1 – central portion
of acinus immediately
surrounding terminal
hepatic arteriole & portal
venule
Zone 2 – between zone 1
& 3
Zone 3 – most peripheral
part, most susceptible to
anoxic injury.
Tuesday, September 18, 2018
7. HEPATIC CIRCULATION
Hepatic artery – branch of ciliac trunk (20-
25%)
Portal vein – collects from mesenteric &
splenic vascular bed ( 75-80%)
Hepatic vein – sinusoids drain into central
vein, all central veins joins to form right &
left hepatic veins which drains into inferior
venacava.
Tuesday, September 18, 2018
8. HEPATIC BILIARY SYSTEM
Intra hepatic Biliary
system – bile secreted by
hepatic cells into canaliculi
which form hexagonal
network around liver cells
At periphery canaliculi
becomes continuous with
intralobular ductules –
joins together to form
hepatic duct
Tuesday, September 18, 2018
9. EXTRA HEPATIC BILIARY
APPARATUS
Gall Bladder – pear
shaped sac beneath
liver, 30-50 ml
capacity, stores bile
Extra hepatic ducts.
Hepatic duct
Cystic duct
Common bile duct.
Tuesday, September 18, 2018
10. EXTRA HEPATIC DUCTS.
Hepatic duct – right &
left hepatic ducts from
2 sides joins to bile
common hepatic duct
(4 cm)
Cystic duct (4cm) –
connects neck of gall
bladder to common
hepatic duct to form
CBD
Tuesday, September 18, 2018
11. EXTRA HEPATIC DUCTS.
Common bile duct (8
cm)
Joins pancreatic duct to
form common
hepatopancreatic duct
(Ampulla of Vater)
Opens into 2nd
part of
duodenum at major
duodenal papilla.
Surrounded by sphincter
of Oddi.
Tuesday, September 18, 2018
12. FUNCTIONS OF LIVER
Secretory function
Metabolic function
Carbohydreate
Fat
Protein
Detoxicating and protective function.
Storage function
Excretory function
Synthesis function
Miscellaneous function.
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13. SECRETORY FUNCTION
Liver – exocrine gland
Secrete bile for digestion and absorption of
fats.
Tuesday, September 18, 2018
15. DETOXICATING AND
PROTECTIVE FUNCTION.
Kupffer cells –
removes bacteria &
cleansing action
Detoxify drugs by
oxidation, hydrolysis,
reduction &
conjugation.
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16. STORAGE FUNCTION
Glucose ( in the form of Glycogen), Vit B12, Vit A
Blood iron buffer & iron storage medium in the
form of ferritin & hemosiderin.
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18. SYNTHESIS FUNCTION
Plasma proteins – albumin & α & β globulin
Coagulation factors I,V, VII, IX & X
Enzymes – alkaline phosphatase. SGPT, SGOT
Removes ammonia to synthesize urea
Cholesterol.
Tuesday, September 18, 2018
19. MISCELLANEOUS FUNCTION.
Reservoir of blood – about 650 ml
Erythropioiesis
Hormone metabolism
Inactivation of insulin, glucagon, vasopressin
Reduction & conjugation of oestrogen,
testosterone, cortisol, aldosterone.
Destruction of RBC
Thermal regulation.
Tuesday, September 18, 2018
20. BILE
Digestive juice formed
in liver.
Hepatocytes to bile
canaliculi
Common hepatic duct
Cystic duct
Common bile duct
Tuesday, September 18, 2018
22. COMPOSITION OF BILE
Bile formed in hepatocytes & released into canaliculi.
Its an alkaline juice comprised of
Water & solids (organic/inorganic)
Organic – bile salts, pigments, cholesterol, lecithin, FA, alkaline
phosphatase
Inorganic – Na+, K+, Ca+, HCO3- & Cl-
Tuesday, September 18, 2018
23. COMPOSITION OF BILE
Bile salts
Bile pigments
Phospholipids
Cholesterol
Electrolytes.
Tuesday, September 18, 2018
24. FORMATION OF BILE SALTS
Bile salts
Formation
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25. FUNCTIONS OF BILE SALTS
Emulsification of fats
Acceleration of action of pancreatic lipase
Micelle formation
Absorption of fat soluble vitamins
Cholerectic action- formation of bile
Cholesterol kept in soluble form in gall
bladder
Intestinal motility.
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27. BILE PIGMENTS
Mainly Bilirubin & Biliverdin
From metabolite of hemoglobin.
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28. OTHER CONTENTS
Phospholipids – Primarily Lecithins.
Cholesterol – by product of bile salts synthesis.
Normal level in bile – 60-170 mg/dl
Electrolytes
Cl- & HCO3- mainly.
Tuesday, September 18, 2018
29. FUNCTIONS OF GALL BLADDER
(RECSS)
Regulates equalization of pressure in biliary
system
Effect on pH of bile
Concentration of bile – becomes thicker,
viscous & darker
Storage of bile – 30-50 ml
Secretion of mucous
Tuesday, September 18, 2018
30. FUNCTIONS OF BILE
MADE-(LPC)2
Digestive function - FATS
Absorptive function – fats & Vit
Excretory function – heavy metals, toxins , bacteria, lecithin
Laxative action – GIT motility
Protective action – Natural detergent.
Cholerectic action – secretion of bile.
Maintenance of pH of gastrointestinal tract.
Prevention of gall stone formation
Lubricating function.
Cholegogue function – Increases release of bile from gall bladder.
Tuesday, September 18, 2018
31. REGULATION OF BILE
Regulation of biliary
secretion
Regulation of release
of bile from gall
bladder.
Tuesday, September 18, 2018
32. REGULATION OF BILIARY
SECRETION
Regulation of bile Indepedent fraction of biliary
secretion
Regulation of bile depedentr fraction of biliary
secretion
Tuesday, September 18, 2018
33. REGULATION OF BILE INDEPEDENT
FRACTION OF BILIARY SECRETION
Its amount of fluid containing water &
electrolytes.
Controlled by secretin & vagal stimulation.
Secretin – produces watery secretion rich in
HCO3 – via cAMP.
Vagovagal reflex – initiated during intestinal
phase of digestion through Ach.
Tuesday, September 18, 2018
34. REGULATION OF BILE DEPEDENT
FRACTION OF BILIARY SECRETION
Quantity of bile salts by liver.
Directly proportional amount of bile salts
reabsorbed from portal circulation.
Cholerectics enhances bile salts secretion by
hepatocytes.
Tuesday, September 18, 2018
35. REGULATION OF RELEASE OF
BILE FROM GALL BLADDER.
Filling of gall bladder – controlled by
pressure gradient.
During interdigestive period as sphincter of oddi
closed bile goes to gall bladder & pressure rises to
7 cm of H2O
Emptying of gall bladder – during digestive
period as sphincter of oddi relaxed pressure
in gall bladder rises to 20 cm of H2O bile
enters to duodenum.
Tuesday, September 18, 2018
36. RELEASE OF BILE
CONTROLLED BY
Hormones – CCK
Fats & protein digestion products stimulate
secretion of CCK which causes contraction of gall
bladder & relxation of sphincter of oddi.
Neural
Vagal stimulation during gastric phase of digestion
causes contraction of gall bladder.
Cholegogue – Substances causing
contraction of gall bladder.
Tuesday, September 18, 2018
37. APPLIED ASPECTS
Disorders of liver and
gall bladder
Jaundice or icterus.
Cirrhosis of liver
Viral hepatitis
Cholecystitis – Gall
bladder inflammation.
Tuesday, September 18, 2018
38. JAUNDICE OR ICTERUS
Yellowish
discolouration of skin
& mucous membrane
due to raised bilirubin
in blood.
Normal value – 0.3-1
mg/dl
Jaundice > 2 mg/dl
Tuesday, September 18, 2018
39. TYPES OF JAUNDICE
Haemolytic – prehepatic
Hepatocellular – Hepatic
Obstructive – post hepatic
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40. CIRRHOSIS OF LIVER
Irreversible chronic
damage to liver with
extensive fibrosis &
regenerative nodule
formation.
Tuesday, September 18, 2018
41. VIRAL HEPATITIS
Cause – hepatitis virus – A,B,C,D,E,F & G
Hepatitis B hepatitis Most common
Clinical features
Odema
Haemorrhagic disorders
Muscle weakness, tremors, convulsions
Hepatomegaly, ascites
Steatorrhoea
Anaemia, jaundice
Raised SGPT, SGOT, Blood urea
Tuesday, September 18, 2018
42. GALL STONE
Cholelithiasis – gall stone
formation.
Types
Cholesterol stone – 80-85%
Due to precipitation of
cholesterol
Radioluscent – cannot seen.
Pigment stones – Ca
bilirubinate stones
15-20 %, Radiopoaque.
Tuesday, September 18, 2018
43. LIVER FUNCTION TESTS
Tests to assess Secretory functions of liver
Tests to assess Metabolic functions of liver.
Tests to assess Synthesis of function of liver.
Tests to assess Detoxication function of liver.
Tests to assess Hepatic cellular integrity.
Miscellaneous tests
Tuesday, September 18, 2018
46. TESTS TO ASSESS SYNTHESIS
OF FUNCTION OF LIVER.
Estimation of plasma proteins –
Hypoalbuminemia & reversal of A:G ratio
Serum liver enzymes level – raised
Transaminase & alkaline phosphatase
Blood urea - < 20-40 mg/dl
Blood ammonia - > 20-80 mg/dl
Coagulation factors – II,V, VII, IX & X
decreases.
Tuesday, September 18, 2018
47. TESTS TO ASSESS DETOXICATION
FUNCTION OF LIVER.
Bromsulphthalein excretion test.
Rate of removal of BSP from blood depends on
functional efficiency of liver & rate of hepatic blood
flow.
Tuesday, September 18, 2018
48. TESTS TO ASSESS HEPATIC
CELLULAR INTEGRITY.
USG – to detect
cirrhosis of liver, fatty
liver, abcesses, cysts,
tumours, gall stones &
dilatation of biliary
system.
CT scan
Tuesday, September 18, 2018