Structure of the

liver, gallbladder and

pancreas

Sanjaya AdikariDepartment of Anatomy

Hepatic ducts

Common hepatic duct

Cystic duct

Common bile duct

Pancreatic duct

Ampulla of Vater

Sphincter of Oddi

Ampulla of Vater

Liver

• Largest gland in the body

• Second largest organ

• Principal metabolic organ

• 70-80% of its blood comes from portal

vein

• 20-30% of its blood comes from hepatic

artery

• Everything absorbed, except lipids, enter

it

Functions of the liver

• Fat metabolism

• Carbohydrate metabolism

• Protein metabolism

• Storage

• Drug, toxin and alcohol metabolism

• Secretion of bile

Liver

Pig liver lobules have clear connective tissue boundaries

Formed by hexagonal structural units called liver lobules

Lobules have a central venule

Lobules are surrounded by portal tracts

LiverHuman liver

lobules do not

have clear

connective

tissue

boundaries

Lobules are

defined by the

arrangement of

portal tracts

around central

venule

Structure of a lobule• The main functional cell is hepatocyte

• Hepatocytes are arranged in plates

• Between hepatocyte plates are sinusoids and bile canaliculi

• Sinusoids are lined with fenestrated endothelium

• Between the endothelium and the hepatocytes lie the space of Disse

Structure of a lobule• Blood from the branches of hepatic artery

and portal vein enter the sinusoids

• Blood is drained by central venule, branch of hepatic vein

• Bile flow in the bile canaliculi is opposite to the blood flow in the sinusoids

• Central venule collects blood from one lobule

• Portal tracts supply several lobules around them

Arrangement of portal

tracts and central venules

Bile ductule

Arrangement of sinusoids and bile canaliculi

Bile ductule

Lining cells of sinusoids

Three types

• Endothelial cells

• Kupffer cells

• Stellate cells or hepatic lipocytes

Stores vitamin A

In response to liver injury produces large

amounts of collagen causing fibrosis that may

lead to hepatic cirrhosis

Kupffer cells

These are phagocytic

cells

Removes aged

erythrocytes and

particulate matter from

circulation

Portal tracts (Portal triads)

Branch of the hepatic

portal vein

Branch of the hepatic

artery

Bile ductule

Limiting plate

The layer of

hepatocytes

immediately

bordering the portal

tract is called the

limiting plate

The limiting plate gets

disturbed in diseases

like hepatitis

Sinusoids and spaces of Disse

Endothelium has

no basement

membrane

Space of Disse lies

between the

endothelium and

hepatocytes

Space of Disse

drains into the

lymphatics of

portal tracts

Hepatic acinus

Roughly diamond shaped

Consists of liver parenchyma centred around a portal tract

Acinus is divided into three zones

Zone 1 - Receives most oxygenated blood

Zone 3 - Receives least oxygenated blood

Gallbladder

Bile in the common

hepatic duct enters the

gallbladder

Bile is stored and

concentrated in it

Capacity is about 100 ml

Contracts in response to

CCK

Bile is an emulsifying

agent

GallbladderSimple columnar epithelium

PancreasHas exocrine and endocrine components

Under the influence of autonomic nerves, gastrin and CCK

Secretes enzymes that digest proteins, lipids and carbohydrates

Secretes insulin, glucagon, somatostatin, and some other hormones

Cells - Insulin

Cells - Glucagon

Cells - Somatostatin

Pancreatic acini

Pyramidal shaped cells

Lumen

Intercalated ducts