The document discusses the anatomy and functions of the liver and gallbladder, including their roles in digestion and bile production. It outlines the structural units of the liver, the formation of bile and bile salts, and the functions of both organs, such as metabolic processes and bile storage. Additionally, it touches on common pathologies related to these organs, like jaundice and gallstones.

1. LIVER, BILE & GALLBLADDER
By
Dr. Faraza Javaid

2. LIVER & GALLBLADDER
• The liver and gallbladder are the two accessory organs of
the gastrointestinal tract, which carry out a multifunctional
role that aids digestion and homeostasis.
• The liver consists of several lobes and receives its blood
supply mainly from the hepatic portal vein.
• The gallbladder is found inferiorly to the liver, being involved
in the storage and release of bile into the duodenum.

3. Location Liver: Epigastric regions
Gallbladder: Right upper quadrant
Parts Liver: Diaphragmatic surface, visceral surface, right
lobe, left lobe, caudate lobe, quadrate lobe, segments
Gallbladder: Fundus, body, beck, biliary tract
Blood vessels Liver: Hepatic artery, hepatic portal vein, hepatic veins
Gallbladder: Cystic artery, right hepatic artery, posterior
superior pancreaticoduodenal artery, gastroduodenal
arteries, cystic veins
Innervation Sympathetic: Celiac and superior mesenteric plexuses
Parasympathetic: Vagus nerve

4. LIVER
• Liver is made up of many lobes called hepatic lobes. Each lobe
consists of many lobules called hepatic lobules.
• Hepatic lobule is the structural and functional unit of liver.
There are about 50,000 to 100,000 lobules in the liver. The
lobule is a honeycomb-like structure and it is made up of liver
cells called hepatocytes
• Each lobule is surrounded by many portal triads. Each portal
triad consists of three vessels:
• 1. A branch of hepatic artery
• 2. A branch of portal vein
• 3. A tributary of bile duct.

7. BILIARY SYSTEM
• Biliary system or extrahepatic biliary apparatus is
formed by gallbladder and extrahepatic bile ducts (bile
ducts outside the liver).
• Right and left hepatic bile ducts which come out of
liver join to form common hepatic duct.
• It unites with the cystic duct from gallbladder to form
common bile duct. All these ducts have similar
structures.

9.  Common bile duct unites with pancreatic duct to form the
common hepatopancreatic duct or ampulla of Vater,
which opens into the duodenum.
 There is a sphincter called sphincter of Oddi at the lower
part of common bile duct, before it joins the pancreatic
duct. It is normally kept closed; so the bile secreted from
liver enters gallbladder where it is stored.
 Upon appropriate stimulation, the sphincter opens and
allows flow of bile from gallbladder into the intestine.

10. PROPERTIES AND COMPOSITION
OF BILE

11. Formation of Bile and
Bile Salts

12.  Bile acid synthesis occurs in liver cells, which
synthesize primary bile acids (cholic
acid and chenodeoxycholic acid in humans) via cytochrome
P450-mediated oxidation of cholesterol in a multi-step process.
 The rate-limiting step in synthesis is the addition of a hydroxyl
group of the 7th position of the steroid nucleus by the
enzyme cholesterol 7 alpha-hydroxylase. This enzyme is down-
regulated by cholic acid, up-regulated by cholesterol.
 In liver, bile acids are conjugated with glycine (amino acid) or
taurin (derivative of an amino acid) and form conjugated bile
acids. These bile acids combine with sodium or potassium ions
to form the salts, sodium or potassium glycocholate and sodium
or potassium taurocholate.

14. BILE PIGMENTS
 Bile pigments are the excretory products in bile. Bilirubin
and biliverdin are the two bile pigments and bilirubin is
the major bile pigment in human beings.
 Bile pigments are formed during the breakdown of
hemoglobin, which is released from the destroyed RBCs in
the reticuloendothelial system.

15. Formation of Bilirubin

18. FUNCTIONS OF BILE SALTS
1.Emulsification of Fats (Fat breakdown)
2.Absorption of Fats (Via Bile)
3.Choleretic Action (Enhance bile secretion)
4.Cholagogue Action (Gallbladder contraction)
5.Laxative Action (Stimulate peristalsis)
6.Prevention of Gallstone Formation (Recycling of
cholesterol)

19. FUNCTIONS OF GALLBLADDER
 Storage of Bile
 Concentration of Bile
 Maintenance of Pressure in Biliary System

20. FUNCTIONS OF LIVER
 METABOLIC FUNCTION
 STORAGE FUNCTION
 SECRETION OF BILE
 HEAT PRODUCTION
 HEMOPOIETIC FUNCTION
 INACTIVATION OF HORMONES AND DRUGS
 DEFENSIVE AND DETOXIFICATION FUNCTIONS

21. PATHOHYSIOLOGY OF LIVER & GALL BLADDER
 JAUNDICE OR ICTERUS
 HEPATITIS
 CIRRHOSIS OF LIVER
 GALLSTONES

22. THANK YOU