Liver
- Largest organ in the body
- Occupies right hypochondrium and extends into epigastrium
- Protected by ribs and costal cartilages
- Its relations include
- Abdominal part of the oesophagus
- Stomach
- Duodenum
- Hepatic flexure of colon
- Right kidney and adrenal gland
- Divided into right and left lobes by the falciform ligament
- Right lobe also divided into
- Quadrate lobe
- Caudate lobe
- Quadrate and caudate lobes are functionally part of the left lobe
- Liver is surrounded by fibrous capsule
- Porta hepatis is found on the posterior-inferior surface
- Free edge of less omentum is attached to margins of porta hepatis
- Porta hepatis contains
- Right and left hepatic ducts
- Right and left branches of hepatic artery
- Portal vein
- Hepatic lymph nodes
- Blood supply is from the hepatic artery and portal vein
- Blood is mixed in the central vein of each liver lobule
- Venous drainage is via the hepatic veins into the vena cava
Peritoneal attachments
- Falciform ligament ascends from umbilicus
- Within falciform ligament runs the ligamentum teres
- This is the remains of the umbilical vein
- On the surface of the liver the falciform ligament splits in two
- Right side forms the upper layer of the coronary ligament
- Left side form upper layer of left triangular ligament
- Extremity of coronary ligament form the right triangular ligament
- Area devoid of peritoneum is known as the bare area
Extrahepatic biliary apparatus
- Extrahepatic biliary apparatus consists of
- Right and left hepatic ducts
- Common hepatic duct
- Common bile duct
- Gallbladder
- Cystic duct
- Right and left hepatic ducts emerge from right and left lobe in
porta hepatis
- Unite to form common hepatic duct which is about 4 cm long
- Common hepatic duct descends in free edge of less omentum
- Joined by cystic duct to form common bile duct
- Common bile duct is about 8 cm long
- Lies in free edge of lesser omentum
- Then passes behind first part of duodenum and lies in posterior
aspect of pancreas
- Drains into second part of duodenum at the ampulla of Vater
- Terminal part is surrounded by Sphincter of Oddi
Gallbladder
- Lies on visceral surface of liver
- Divided into fundus, body and neck
- Fundus projects from inferior margin of liver
- Comes into contact with abdominal wall at level of tip of 9th costal
cartilage
- Neck is continuous with cystic duct
- Relations include
- Anterior abdominal wall
- Visceral surface of liver
- Transverse colon
- First and second parts of duodenum
- Blood supply is from cystic artery, a branch of the right hepatic
artery
- Cystic vein drains directly into the portal vein
- Cystic duct is about 4 cm long and anatomical variations are common
Pancreas
- The pancreas develops from ventral and dorsal pancreatic buds
- Ventral bud produces the head and the uncinate process and the
accessory duct
- Dorsal bud gives rise to the body and tail
- The pancreas is situated retroperitoneally
- It is a combined endocrine and exocrine gland
- Divided into head, neck, body and tail
- Head lies within the curve of the duodenum
- Uncinate process projects from the head
- Superior mesenteric vessels separate the head from the body
- Tail extends into the lienorenal ligament along with the splenic
artery
- Anterior relations include transverse mesocolon and stomach
- Posterior relations include inferior vena cava, aorta, portal vein,
common bile duct and left kidney
- Superior relations include first part of duodenum and splenic artery
- Pancreatic ducts has two ducts
- Main pancreatic duct
- Accessory pancreatic duct
- The main pancreatic duct begins in the tail
- Drains into the second part of the duodenum together with the common
bile duct
- The main duct is also known as the Duct of Wirsung
- Accessory duct begins in the head
- The accessory duct is also known as the Duct of Santorini
- It usually drains into the main duct but can open separately into
the duodenum
- Blood supply is from the superior and inferior pancreaticoduodenal
arteries
- Superior pancreaticoduodenal artery is an indirect branch of hepatic
artery
- Inferior pancreaticoduodenal artery is a branch of superior
mesenteric artery
- Splenic artery supplies the body and tail
- It is a direct branch of the coeliac trunk
- The venous drainage corresponds to the arterial supply and drain
into the portal system
Histology
- 80 – 90 % of the mass is composed of acinar cells
- These form the exocrine portion of the gland
- Islets of Langerhans are dispersed within the gland
- They form islands of endocrine tissue
- The islets consist of Types A (20%), B (70%) and D (10%) cells
- Type A cells produce glucagons
- Type B produce insulin
- Type D produce somatostatin
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