T1 L6 Anatomy of the liver Flashcards
How much does the liver weigh?
1.4-1.6kg
Where is the liver?
Below the diaphragm Mostly in right hypochondriac & epigastrium On right w.r.t the stomach Above colon Overlies gallbladder
What are the main functions of the liver?
Detoxification
Protein synthesis
Production of bile - accessory GI organ
Glycogen storage
Where is the falciform ligament?
In the midline & attaches the liver to the anterior abdominal wall
Ligamentum teres is at the lower end
What are the 4 lobes of the liver?
Left lobe
Right lobe
Quadrate
Caudate
What is the round ligament?
Obliterated left umbilical vein
Extends to umbilicus
What is the coronary ligament?
Links diaphragm to liver
What is the lesser omentum?
Links liver to stomach
From lesser curvature of stomach to aorta hepatis
Has a free margin
Close to stomach & encloses gastric arteries & veins
What does the lesser omentum enclose?
Hepatic artery
Portal vein
Bile duct
Lymph vessels
What supplies blood to the liver?
Hepatic artery
Give some hepatic artery variations
Right hepatic artery replaced by superior mesenteric artery
Left hepatic artery replaced by left gastric artery
Trifurcation of common hepatic artery - right hepatic artery, left hepatic artery, gastroduodenal artery
What is the porta hepatis?
At hilum of liver - visceral surface
Deep fissure
What enters/exits through the porta hepatis?
Hepatic portal vein
Hepatic artery proper
Common hepatic duct
Nerves & lymphatics
What is a liver lobule?
Functional unit of the liver Hexagon shaped Contains hepatocytes Hepatocytes secrete bile Portal triad at corners
How are the anatomical lobes divided?
According to how hepatic artery & portal vein subdivides
Branches of hepatic artery & portal vein carry blood into sinusoids
Branches of bile duct accompany those of hepatic artery & portal vein
What do hepatocytes do?
Synthesise & release plasma proteins into blood albumin
Deaminates amino acids - urea into blod
Bilirubin to bile pigments
Bile salts - emulsification of fats
What is the venous drainage of the liver?
Mixed blood from 2 sources (portal & hepatic) into the sinusoids passes through hepatocytes & into central vein
Describe the central vein
Found at centre of hepatic lobule
Drains into sub lobular vein
Sublobular veins drain into hepatic veins
Hepatic veins drain into inferior vena cava
What are portal systemic anastomosis?
Communications between some branches of the portal & systemic systems
Important if portal vein is blocked or the passage via the liver meets resistance - portal hypertension. Allows collateral return of blood to heart
What is the anastomosis of the abdominal part of the oesophagus?
Left gastric tributaries with oesophageal branches azygos
What is the anastomosis of the anal canal?
Superior rectal anastomoses with middle & inferior rectal
What is the anastomosis of the umbilicus?
Paraumbilical veins with epigastric veins
What is portal hypertension?
Common clinical condition
Obstruction of portal vein –> increase in pressure –> hypertension
Anastomoses between portal & systemic means back flow of blood to heart & then lungs
Varicoses
Caput medusa
What is a portacaval shunt?
Reduction of hypertensions
Diverts blood from portal to systemic
Used less frequently since the creation of TIPS
What is bile?
Secreted by hepatocytes into bile canaliculi
40ml/hour
Closed sphincter Oddi to duodenum –> bile flows to gallbladder to be stored & concentrated
Describe the lymphatic drainage
Lymph nodes in porta hepatis
Pass to coeliac nodes
Drain to cisterna chyli
Describe liver trauma
Closely related to lower ribs
Fracture ribs / penetrating wounds
High vascularisation –> severe haemorrhage
