Liver structure and function Flashcards
how many lobes does the liver have and what are they?
2 major - right and left
2 minor - caudate and quadrate
where do the vessels and nerves enter the liver?
at the porta which is on the inferior surface
what all enters the liver at the porta?
blood vessels - hepatic artery and hepatic portal vein
ducts - right/left hepatic ducts –> common hepatic duct)
lymphatic vessels
nerves - hepatic nerve plexus
the common hepatic duct joins which duct from the gallbladder?
cystic duct
what is at the junction of the common bile duct and pancreatic duct?
sphincter of Oddi
major duodenal papilla
what is the name of the ligament which within the liver and separates the right from the left lobe?
falciform ligament
how is the liver peritonised?
intraperitoneal
where is the bare area of the liver located and what is it surrounded by?
the diaphragmatic surface
covered by coronary ligament
at the porta, what is the function of the connective tissue capsule ?
the connective tissue capsule branches throughout the liver forming a network of septa (wall) to provide support
what is involved in the portal triad and where is it located?
hepatic artery, vein and duct
located at the corner of each hexagonal lobe
where are the central veins located in the liver?
the centre of each lobe
describe the structure of the central veins in the liver.
hepatic cords radiate out from the central veins
cords are composed of hepatocytes
between the cells lie bile canaliculus
the gaps between each hepatic cord are fenestrated blood vessels called sinusoids
what are the 6 components of bile?
bile acids
lecithin
cholesterol
(top 3 solubilise fat and are synthesised in the liver)
bile pigments (bilirubin from haemoglobin)
toxic metals (detoxification in the liver)
bicarbonate for neutralisation
what are the 5 components of bile secreted from?
bicarbonate is secreted from duct cells
hepatocytes
what are bile pigments?
breakdown products of haemoglobin from old/damaged RBC (erythrocytes)
what makes bile yellow?
bilirubin from erythrocytes is extracted from the blood by hepatocytes and secreted in bile
what makes faeces brown?
bilirubin is modified by bacterial enzymes making brown pigments
what makes urine yellow?
reabsorbed bilirubin from the intestine causes it to be extracted in our urine
what are bile acids synthesised in our liver from?
cholesterol
before bile acids can be secreted what happens and why?
binds with glycine or taurine to increase solubility
secreted bile salts are recycled via what circulation?
the enterohepatic circulation
what is the difference between bile acids and bile salts?
bile acids is produced from the liver but bile salts are bile acids + glycine or taurine because it cannot be excreted as bile acid as it is insoluble
the gallbladder only has 3 layers, what are these?
mucosa
muscularis
serosa
what is the main controller of bile secretion into the duodenum?
sphincter of oddi
by how many times does the gallbladder concentrate bile?
5-20 times
fat in the duodenum causes the release of what?
CCK
when CCK is released what happens?
the sphincter of Oddi relaxes and the gallbladder contracts (releasing bile)
what does CCK control?
pancreatic enzyme and bile secretion
what triggers the secretion of secretin?
acid in the duodenum
what affects does secretin have?
decreases acid secretion
decreases gastric emptying
increase duodenal, pancreatic and bile duct HC03 secretion
= neutralisation
what affects does CCK have?
decreases gastric emptying increases pancreatic enzyme secretion from acing cells gallbladder contraction relaxation of sphincter of oddi = digestion
