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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