2. GIT Module
2nd year MBBS, Batch 50 (2024)
Short Group Discussion (SGD)
Date:- 10th March 2024
Usman. Habib
Functions of the Liver, and Gallbladder
3. Table of Contents
Sr # Content Slide #
1 Motto, Vision 4
2 Professor Umar Model of Integrated Lecture 5
3 Bloom’s Taxonomy(Domains of learning) 6
4 Diagrammatic Representation of Blooms Taxonomy 7
5 Learning Objectives 8
6 Horizontal Integration 9-14
7 Core Concept 11-24
8 Vertical Integration 44-53
9 Biomedical Ethics(lesson of the day) 54-56
10 Brainstorming(SEQ relevant with lecture) 57-61
10
Suggested Research Article 62-64
11 Promoting IT and research culture(Digital Library) 65
13 References of this lecture 66
4. Motto Vision; The
Dream/Tomorrow
• To impart evidence
based research oriented
medical education
• To provide best possible
patient care
• To inculcate the values
of mutual respect and
ethical practice of
medicine
4
8. LEARNING OBJECTIVES
8
Sr. # Learning Objective Domain of Learning
1
Describe the functions of the liver and
gallbladder
C1
2
Discuss the physiological mechanisms associated
with the Hepato-biliary system.
C2
3
To apply the core physiological concepts to
understand the pathophysiological aspects of
relevant clinical conditions.
C3
10. 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.
Saturday, March 16, 2024
Horizontal
Integration with
Anatomy
11. 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.
Saturday, March 16, 2024
Horizontal
Integration with
Anatomy
12. 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.
Saturday, March 16, 2024
Horizontal
Integration with
Anatomy
13. 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.
Saturday, March 16, 2024
Horizontal
Integration with
Anatomy
14. 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.
Saturday, March 16, 2024
Horizontal
Integration with
Anatomy
15. 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
Saturday, March 16, 2024
CORE
CONCEPT
16. 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.
Saturday, March 16, 2024
CORE
CONCEPT
17. 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
Saturday, March 16, 2024
Horizontal
Integration with
Anatomy
18. 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.
Saturday, March 16, 2024
Horizontal
Integration with
Anatomy
19. Functions Of Liver
• Secretory function
• Metabolic function
• Carbohydreate
• Fat
• Protein
• Detoxicating and protective function.
• Storage function
• Excretory function
• Synthesis function
• Miscellaneous function.
Saturday, March 16, 2024
CORE
CONCEPT
20. Secretory Function
• Liver – exocrine gland
• Secrete bile for digestion and absorption of fats.
Saturday, March 16, 2024
CORE
CONCEPT
22. Detoxicating And Protective
Function.
• Kupffer cells – removes
bacteria & cleansing
action
• Detoxify drugs by
oxidation, hydrolysis,
reduction &
conjugation.
Saturday, March 16, 2024
CORE
CONCEPT
23. Storage Function
• Glucose ( in the form of Glycogen), Vit B12, Vit A
• Blood iron buffer & iron storage medium in the form
of ferritin & hemosiderin.
Saturday, March 16, 2024
CORE
CONCEPT
24. Excretory Function
• Exogenous dyes like bromsulpthalein & rose Bengal
dye are excreted.
Saturday, March 16, 2024
CORE
CONCEPT
25. 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.
Saturday, March 16, 2024
CORE
CONCEPT
26. 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.
Saturday, March 16, 2024
CORE
CONCEPT
27. Bile
• Digestive juice formed
in liver.
• Hepatocytes to bile
canaliculi
• Common hepatic duct
• Cystic duct
• Common bile duct
Saturday, March 16, 2024
CORE
CONCEPT
29. 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-
Saturday, March 16, 2024
CORE
CONCEPT
30. Composition Of Bile
• Bile salts
• Bile pigments
• Phospholipids
• Cholesterol
• Electrolytes.
Saturday, March 16, 2024
CORE
CONCEPT
31. Formation Of Bile Salts
• Bile salts
• Formation
Saturday, March 16, 2024
CORE
CONCEPT
32. 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.
Saturday, March 16, 2024
CORE
CONCEPT
34. Bile Pigments
• Mainly Bilirubin & Biliverdin
• From metabolite of hemoglobin.
Saturday, March 16, 2024
CORE
CONCEPT
35. Other Contents
• Phospholipids – Primarily Lecithins.
• Cholesterol – by product of bile salts synthesis.
• Normal level in bile – 60-170 mg/dl
• Electrolytes
• Cl- & HCO3- mainly.
Saturday, March 16, 2024
CORE
CONCEPT
36. Functions Of Gall Bladder
• 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
Saturday, March 16, 2024
CORE
CONCEPT
37. Functions Of Bile
• 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.
Saturday, March 16, 2024
CORE
CONCEPT
38. Regulation Of Bile
• Regulation of biliary
secretion
• Regulation of release of
bile from gall bladder.
Saturday, March 16, 2024
CORE
CONCEPT
39. Regulation Of Biliary Secretion
• Regulation of bile Indepedent fraction of biliary
secretion
• Regulation of bile depedentr fraction of biliary
secretion
Saturday, March 16, 2024
CORE
CONCEPT
40. 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.
Saturday, March 16, 2024
CORE
CONCEPT
41. 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.
Saturday, March 16, 2024
CORE
CONCEPT
42. 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.
Saturday, March 16, 2024
CORE
CONCEPT
43. 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.
Saturday, March 16, 2024
CORE
CONCEPT
44. 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
Saturday, March 16, 2024
Vertical Integration
with Gastroenterology
45. Types Of Jaundice
• Haemolytic –
prehepatic
• Hepatocellul
ar – Hepatic
• Obstructive –
post hepatic
Saturday, March 16, 2024
Vertical Integration
with Gastroenterology
46. Cirrhosis Of Liver
• Irreversible chronic
damage to liver with
extensive fibrosis &
regenerative nodule
formation.
Saturday, March 16, 2024
Vertical Integration
with Gastroenterology
47. 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
Saturday, March 16, 2024
Vertical Integration
with Gastroenterology
48. 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.
Saturday, March 16, 2024
Vertical Integration
with Gastroenterology
49. 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
Saturday, March 16, 2024
Vertical Integration
with Gastroenterology
55. The four principles of Beauchamp and Childress
• The four principles of Beauchamp and Childress have been extremely influential in the field
of medical ethics, and are fundamental for understanding the current approach to ethical
assessment in health care. 55
56. Non-maleficence (Lesson of the day)
• The principle of non-maleficence holds that there is an
obligation not to inflict harm on others.
• Example: stopping a medication known to be harmful or
refusing to give a medication to a patient if it has not
been proven to be effective.
56
Understanding
Biomedical Ethics
58. QUESTIONS
1) Which of the following abolishes “receptive relaxation” of the
stomach?
(A) Parasympathetic stimulation
(B) Sympathetic stimulation
(C) Vagotomy
(D) Administration of gastrin
(E) Administration of vasoactive intestinal peptide (VIP)
58
Brain Storming
Brainstorming/Review
59. 59
Ans: C
“Receptive relaxation” of the orad region of the stomach is
initiated when food enters the stomach from the
esophagus.
This parasympathetic (vasovagal) reflex is abolished by
vagotomy
Brainstorming/Review
60. QUESTIONS
2) Which of the following substances inhibits gastric
emptying?
(A) Secretin
(B) Gastrin
(C) Cholecystokinin (CCK)
(D) Vasoactive intestinal peptide (VIP)
(E) Gastric inhibitory peptide (GIP)
60
Brainstorming/Review
61. Answer
• The answer is C.
• Cholecystokinin (CCK) is the most important hormone
for digestion and absorption of dietary fat. In addition to
causing contraction of the gallbladder, it inhibits gastric
emptying. As a result, chyme moves more slowly from
the stomach to the small intestine, thus allowing more
time for fat digestion and absorption
61
Brain Storming
64. Saturday, March 16, 2024
•Background:
•Jaundice is prevalent in clinical practice, characterized by serum bilirubin levels
exceeding 3 mg/dL.
•Summary:
•This review covers the pathophysiology, clinical approach, and diagnostic and
treatment strategies for jaundice.
•Clinical Presentation:
•Manifests as yellow skin and sclera coloration.
•Evaluation:
•Comprehensive assessment involving detailed medical history, physical
examination, and laboratory tests.
•Laboratory Tests:
•Evaluation of hepatic inflammation and cholestatic enzymes along with serum
bilirubin levels.
•Imaging Modalities:
•Necessary for further evaluation and differentiation of jaundice etiology.
•Treatment:
•Tailored to the underlying cause identified through diagnostic evaluation.
Promoting IT &
Research
Culture
Take Home Message of The Research
Article
65. HOW TO ACCESS DIGITAL LIBRARY
• Steps to Access HEC Digital Library
1.Go to the website of HEC National Digital Library.
2.On Home Page, click on the INSTITUTES.
3.A page will appear showing the universities from Public and Private
Sector and other Institutes which have access to HEC National Digital
Library HNDL.
4.Select your desired Institute.
5. A page will appear showing the resources of the institution
6. Journals and Researches will appear
7. You can find a Journal by clicking on JOURNALS AND DATABASE and
enter a keyword to search for your desired journal.
65
Link:https://www.topstudyworld.com/2020/05/access-hec-digital-
library.html?m=1
Promoting IT &
Research Culture
66. References
Sr.# Types of
reference
material
Names/links of reference material
1 Textbook Guyton AC, Hall JE. Textbook of Medical Physiology. 14th ed. Philadelphia,
PA: Saunders; 2020
2 Textbook Boron WF, Boulpaep EL. Medical Physiology: A Cellular and Molecular
Approach. 3rd ed. Philadelphia, PA: Elsevier; 2017.
3 Textbook Sherwood L. Human Physiology: From Cells to Systems. 10th ed. Boston,
MA: Cengage Learning; 2020.
4 Textbook Widmaier EP, Raff H, Strang KT. Vander's Human Physiology: The
Mechanisms of Body Function. 16th ed. New York, NY: McGraw-Hill
Education; 2021.
5 Textbook Costanzo LS. Physiology. 7th ed. Philadelphia, PA: Saunders; 2021.
6 Research
paper
https://doi.org/10.1159/000517301
7 YouTube
Video
https://www.youtube.com/watch?v=O71niTozP-o
