Liver structure and function Flashcards
How much does the liver weigh?
around 1.4kg
How many lobes and sizes?
2 major lobes - right and left, right bigger.
2 smaller lobes: Quadrate and Caudate
What is the porta?
Entry and exit point for pretty much everything into and out of liver
ducts into duodenum - liver to duodenum
common hepatic duct (liver) joins with cystic duct (gall bladder) to form common bile duct. Joins pancreatc duct to open at sphincter of oddi (Major duodenal papilla)
What separates r and l lilobe?
Falciform ligament
Quadrate/ caudate lobe where?
Posterior surface of the liver: caudate superiourly and quadrate inferiorly around the middle.
What is the bare area? What is that bit attached by?
Superior posterior area of the liver (right lobe) which doens’t have any peritoneum but instead attaches directly to the diaphragm. Coronary ligaments surround the bare area and attach to the diaohargm
what does the septa do?
Separate the individual hepatic lobules (hexagons)
what to the central veins drain into?
hepatic veins -> IVC
What is and where is the portal triad?
corner of hexagonal lobules, cont. hepatic portal vein (nutrient rich, oxygen low), hepatic artery (oxygen rich and nutrient low) and hepatic duct (takes bile away, bile travels in canaliculus)
hepatic portal vein and hepatic artery join to drain into what?
CENTRAL VEIN
Are the blood vessels in the liver continuous?
no, they’re discontinuous, so liver is bloody (great ;))
what are the hepatic sinusoids?
hepatic cords (hepatocyes in lines) run out from central vein, the spaces between the cords are the blood channels (HEPATIC SINUSOIDS)
Journey of blood through liver
portal vein and hepatic artery join in hepatic sinusoids. drain through central veins into hepatic veins into ivc
Hepatocyte functions
bile production,
nutrient storage
nutrient interconversion
detox
which vits stored in liver? Which minerals?
ADEK Copper and Fe
What happens to txic metals in the liver?
They get surrounded by proteins, sent off into the bile duct and will eventully be excreted
What are the components of bile?
Bile salts
Lecithin
Cholesterol
^ all synthesized in the liver, help solubilise fat
Bile Pigments (bilirubin - from haemoglobin)
Toxic metals (detoxified)
Bicarbonate
Wat secretes which part?
Bile acids, lecithin, cholesterol, Bile pigments and detoxified toxic metala, all by the hepatocytes
HCO3 by duct cells
Why is poo bronw?
Because of the bilirubin! It is mad efrom broken down dead red blood cells and the modification by bacterial enzymes makes the poop brown
Why is wee yellow?
Reabsorbed bilirubin excreted in urine
What are bile acids made from?
Cholesterol
What is conjucation of bile acids?
acids + glycine/taurine = bile salts (increased solubility)
Where are bile salts get picked up out of duodenum?
illium
What are the 3 layers in the gall bladder?
mucosa, muscularis externa, serous
(NO submucosa)
What happens if sphincter of oddi is closed?
bile etc goes back up into the gall bladder where it is stored and concentrated (Na pumped out and H2O goes with it)
What stimulates the realse of CCK? What happens after CCK is released?
Fats and amino acids in the duodenum
What is the effect of secretin?
Neutralisation of acid!
Secretin released when pH drops, causes:
-slower gastric emptying
-inhibition of parietal cells
-increased HCO3 secretion (duodenal, pancreatic, bile duct)
What is the effect of CCK? What causes its release?
Digestion!
Released in response to fat in duodenum.
Causes:
-release of pancreatic enzymes
-gall bladder contraction
-decreased gastric emptying
-relaxation of the sphincter of Oddi
