Liver Flashcards
Where does the falciform ligament attach?
Anterior liver to the abdominal wall; separated by left and right lobes.
What does the coronary ligaments attach?
Superior liver to diaphragm
Which ligaments attach the liver to the duodenum and stomach?
Lesser omentum
Hepatoduodenal
Hepatogastric
What does the hepatic portal vein do?
Takes blood from the GI tract to the liver for processing, before returning blood to systemic circulation
Which veins drain into the hepatic portal vein?
What organs do they carry blood from?
Superior mesenteric vein(small intestine) Splenic vein (short gastric, gastroepiploic, inferior mesenteric and pancreatic veins). Right and left gastric veins (stomach and oesophagus) Superior pancreaticoduodeal veins (pancreas and duodenum) Cystic vein (gallbladder and paraumbilical veins)
What are porto-systemic anastomoses?
Why are they important?
Anastomoses between portal and systemic circulation.
Allow blood to be shunted into the systemic system to bypass the liver, e.g. in portal hypertension.
What veins combine to form the hepatic portal vein?
Superior mesenteric and splenic vein.
Runs upwards, lies behind the common bile duct and hepatic artery, and anterior to the IVC. Penetrates the right border of the lesser omentum, and runs anterior to the epiploic foramen until it gets to the porta hepatis.
What is the structural unit of the liver?
Hepatic lobules
What are sinusoids?
Low pressure vascular channels receiving blood from the terminal branches of the hepatic artery and the portal vein at the periphery of lobules, which is then delivered to a central vein.
What is the functional unit of the liver?
Hepatic acinus
What composes the hepatic acinus?
Ellipsoidal mass of hepatocytes arranged around the hepatic arterioles and portal venules, just as they anastomose into sinusoids.
What is the sinusoidal epithelium like?
Fenestrated, to allow unimpeded flow of plasma from blood into the space of Disse.
What is the space of Disse?
Space between the hepatocytes and the sinusoidal epithelium; plasma collects here and flows back toward the portal tracts to collect in the lymphatics.
What are Kupffer cells?
Phagocytic cells in the hepatic sinusoids
What are stellate cells?
Pericytes in the space of Disse, involved in liver fibrosis. They store vitamin A and will proliferate and contract in liver damage
How does the liver regenerate?
Can lose up to 70% mass and still regenerate in 5-7 days; hepatocyte hyperplasia when needed.
Hepatocyte growth factor is important in promoting hyperplasia, as well as TNF, EGF and IL6 for regeneration.
TGF-beta inhibits liver cell proliferation.
What are the main functions of the liver?
Filtration and storage of blood Metabolism of carbs, fat, protein, hormones and foreign chemicals Storage site for vitamins Coagulation factor synthesis Detoxification Bile formation and bilirubin metabolism.
How does the liver act as a reservoir of blood?
The liver usually holds 450ml of blood but this can increase by 0.5-1L if high pressure in the RA causes backflow of blood, which is then stored in hepatic veins and sinuses.
How does the liver ‘clean’ blood?
The hepatic macrophage system means bacteria in intestinal blood is phagocytosed by Kupffer cells as blood passes through sinuses.
What vitamins are stored in the liver?
Vitamin A: stellate cells, 10 month supply
Vitamin D: 3-4 month supply
Vitamin B12: 12+ month supply
Iron: stored in the liver as ferritin