Liver Structure and Function Flashcards
What are the four lobes of the liver
Riht, left,caudate,quadrate
What is the nerve supply of the liver
The hepatic plexus which contains sympathetic (from the coeliac plexus) and parasympathetic (from the vagus nerve) all via porta on inferior surface
The caudate lobe is located:
on the visceral surface between the IVC and a fossa formed by ligamentum venosum
The quadrate lobe is located:
between gallbladder and a fossa formed by the ligamentum teres
What does the porta hepatis not transmit
Hepatic veins
What is the liver covered by
A connective tissue (Glisson’s) capsule and visceral peritoneum except at the bare area (small area on diaphragmatic surface surrounded by coronary ligament)
What divides liver hepatocytes into hexagonal lobules
Septa
What is the portal triad
The hepatic artery,portal vein and hepatic duct. They’re located at the corner of each hexagonal lobule
What do the central veins branch to
Hepatic veins that branch into the IVC
What are hepatic cords made out of
Hepatocytes
What are the blood channels bw hepatic cords
Hepatic sinusoids
Where do cannaliculi lead to
Hepatic ducts
What is the alimentary role of liver?
Production and secretion of bile
What are the six components of bile
Bile acids Lecithin Cholesterol Bile pigments (Bilrubin) Toxic metals Bicarbonate (Secreted by duct cells) (All of the rest secreted by hepatocytes)
What are bile pigments
Breakdown products of haemoglobin from old/damaged erythrocytes
What gives bile its yellow colour
Bilrubin (extracted from blood by hepatocytes and secreted into bile)
How does bilrubin turn brown?
modified by bacterial enzymes
what colour is reabsorbed bilrubin excreted in urine
yellow
What are bile acids synthesised from?
cholesterol in liver
What happens to bile acids before secretion
Conjugated with glycine or taurine to increase solubility
How are bile salts recycled
via enterohepatic circulation
What are the three layers in the gallbladder
Mucosa (rugae)
Muscularis (smooth muscle)
Serosa (Connective tissue)
What ducts does the gallbladder empty into
Cystic duct then common bile duct
WHen sphincter of oddi is closed, what happens to bile
Forced back to gallbladder where it is concentrated by 5-20 times
What does fat in duodenum trigger
Release of CCK
What does CCK cause
Sphincter of Oddi relaxes Gallbladder contracts
After fat is solubilised in duodenum CCK released even more and this causes?
pancreatic enzyme secretion and bile secretion
