Liver Structure and Function Flashcards
In which quadrant is the liver the located?
- right upper quadrant
Which large muscle sits above the liver?
- the diaphragm
True or False?
The liver has four major lobes.
False
The liver has two major lobes and two minor lobes.
Name the four lobes of the liver.
- right
- left
- caudate
- quadrate
Which main vein and artery supply the liver?
- hepatic artery
- hepatic portal vein
State the lymphatic supply of the liver.
- via left and right hepatic ducts that then drain into the common hepatic duct
Where does nerve supply of the liver originate?
- hepatic nerve plexus
What joins the hepatic duct and which ducts arise from them?
- cystic duct from the gallbladder joins the hepatic duct
- they form the common bile duct and the pancreatic duct
What runs between the right and left lobes of the liver?
- the round ligament
Which ligament surrounds the bare area and what is its function?
- coronary ligament
- where the liver attaches to the underside of the diaphragm
What covers the branching network of septa into the liver? State where this network originates.
- connective tissue capsule
- at the porta
True or False?
The septa divide into hexagonal lobules.
True
What makes up the portal triad?
- hepatic portal vein
- hepatic artery
- hepatic duct
Where are the portal triads located?
- at each corner of the hexagonal lobules
What travels at the centre of each lobule?
- central veins
Where do the central veins drain?
- into the hepatic veins and then into the inferior vena cava
Which structures radiate out from the central vein?
- hepatic cords
What are the hepatic cords composed of?
- hepatocytes
Describe the bile canaliculus and state where you would find them.
- cleft-like lumen
- lie within each hepatic cord
What are the spaces between the hepatic cords called?
- hepatic sinusoids
What are hepatic sinusoids?
- discontinuous capillaries
What is the function of the hepatic sinusoids?
- they allow dead blood cells the filter out of the system
Describe the blood that runs through the portal system.
- low oxygen
- high nutrient
True of False?
The liver can store an unlimited amount of glycogen.
False.
The liver can only store a certain amount of glycogen (around 18miles)
State the alimentary role of the liver.
- the production and secretion of bile
Name the five components of bile.
- bile acids
- lecithin
- cholesterol
- bile pigments
- toxic metals
- bicarbonate
What is the only component of bile that is not secreted by hepatocytes.
- bicarbonate
How are bile pigments formed?
- they are formed from the breakdown products of haemoglobin from old or damaged erythrocytes
Name the predominant bile pigment.
- bilirubin
True or False?
Bilirubin can be extracted from the blood by hepatocytes.
True.
It is then secreted into bile.
What colour of bile does bilirubin produce?
- yellow
Explain why faeces is usually brown.
- bilirubin that is not extracted by hepatocytes continue into the intestines
- here they are modified by bacterial enzymes
- this leads them to form brown pigments
Explain why urine is usually yellow.
- bilirubin that is reabsorbed maintains its yellow pigment and is excreted in urine
How do bile acids become bile salts? How does this affect solubility?
- they are conjugated with glycine or taurine
- this increases solubility
Through which system are bile salts recycled?
- enterohepatic circulation
Describe the gallbladder.
- sac-like structure
- lies of the inferior surface of the liver
- has folded rugae
To reach the common bile duct, through which duct must gallbladder secretions travel?
- the cystic duct
What structure controls bile secretion?
- the sphincter of Oddi
What happens the bile when the sphincter of Oddi contracts?
- the bile is forced back into the gallbladder
True or False?
The gallbladder concentrates all bile 15 times.
False.
The gallbladder concentrates bile between 5 and 20 times. The number of times depends on how long each period of time is between fatty meals.
Explain how bile is secreted.
- presence of fat in the duodenum triggers the release of CCK
- this triggers the relaxation of the sphincter of Oddi
- it also triggers the contraction of the gallbladder
- this forces bile out of the sphincter of Oddi
