22 Structure of the liver, gall bladder, biliary tract and pancreas Flashcards
Liver:
• Where does it lie?
• Moves with?
• Surrounded by?
- Largest organ
- Lies in upper abdomen under diaphragm
- Moves with position and respiration
- Surrounded by peritoneum except for bare area (related to diaphragm posteriorly)
- Should not be palpable below costal margin
Bile production vs storage location?
- Production of bile = liver
* Storage and concentration = gallbladder
What is Glisson’s capsule?
Deep to its peritoneal covering, the liver is completely surrounded by Glisson’s capsule that is a thin connective tissue layer sending extensions into the organ in-between the lobules
Liver arterial supply?
Venous drainage?
- (Hepatic) portal vein - brings absorbed nutrients from the stomach/intestine
- Hepatic artery proper - supplies hepatocytes (liver cells) with O2
• Venous drainage - by hepatic veins that enter IVC
Bile drainage of liver?
Bile is drained via canaliculi that lie between the hepatocytes –> bile ductules –> bile ducts –> gall bladder
Functions of liver?
- Synthesis and secretion of bile
- Storage of glucose, glycogen, proteins, vitamins and fats
- Detoxification of metabolic waste
- Synthesis of blood clotting and anticoagulant factors (fibrinogen and prothrombin)
Constituents of bile?
- Bile pigments (chiefly bilirubin)
- Cholesterol
- Phospholipids (lecithin)
- Fatty acids
- Water
- Electrolytes
Where do bile pigments derive from?
Breakdown of haemoglobin
What is the role of Kupffer cells?
- Fixed phagocytes
* Play a role in formation of bile pigments
What are functions of bile salts?
- Responsible for detergent and emulsifying effect of bile on fats
- Increase absorption of fats by the small intestine
What is the structure of a liver lobule?
- Sheets of cells (hepatocytes) radiate outwards from the central vein that forms the central axis of the lobule
- Sinusoids lie between these sheets of cells carrying blood from the hepatic artery + portal vein (mixed oxygenated + de-oxygenated blood) –> central vein
- Bile flow is in opposite direction in the canaliculi between the hepatocytes
What is another name for hepatorenal recess?
Morrison’s pouch
What may collect in hepatorenal recess and result in?
- Blood/pus may collect here
* Pus - forms abscesses particularly if the patient is recumbent
What is the rectovesical pouch?
- Males
* Separate rectum from urinary bladder
What is the rectouterine pouch (of Douglas)?
- Females
* Separate rectum from uterus
What is the vesicouterine pouch?
- Females
* Separate urinary bladder from uterus
What are the lobes of the liver?
• Right lobe
• Left lobe
- Caudate lobe
- Quadrate lobe
What structures make up portal triad?
- Portal vein
- Hepatic artery proper
- Hepatic (biliary) ducts
What is the ligament teres (round ligament of liver)?
Obliterated umbilical vein in the free border of the falciform ligament
What is the ligament venosum?
Obliterated ductus venosus
What is the Couinaud Classification?
- Division of liver into 8 functionally independent segments
- Each segment has its own vascular inflow, vascular outflow and biliary drainage
- Each segments can be surgically removed
What are liver “ligaments”?
Reflections of peritoneum that surround the bare area (which is related to the diaphragm, IVC, right kidney and right suprarenal/adrenal gland on the posterior abdominal wall)
Blood supply and venous drainage of liver?
- Hepatic artery proper, a branch of celiac trunk, divides into right and left terminal branches that enter the portal hepatis
- Portal vein divides into right and left terminal branches that enter the portal hepatic behind the arteries
- Hepatic veins (3 or more) emerge from the posterior surface of the liver and drain into the IVC
Lymphatic drainage of liver?
- Liver produces a large amount of lymph (~1/3 or 1/2 of all body lymph)
- Lymph vessels leave the liver and enter several lymph nodes in the portal hepatis
- Efferent vessels pass –> celiac nodes
- A few vessels pass from the bare are of the liver through the diaphragm
