Liver Structure and Function Flashcards
What is the largest internal organ of the body?
Liver
Funny that
What is the largest gland of the body?
Liver
Is the liver an endocrine or exocrine gland?
Mixed
What does the liver sit under?
The diaphragm
How many loops does the liver have?
4
Name the four loops of the liver.
Right loop
Left loop
Caudate loop
Quadrate loop
What makes up the bile system?
Bile ducts and gall bladder which all extend from the liver
What does the pancreatic duct merge with?
Bile duct
What is the main artery for the liver?
Hepatic artery
What is the main vein for the liver?
Hepatic portal vein
What are the common hepatic ducts joined to?
Cystic duct from the gallbladder
What is the duct called when the cystic and hepatic duct merge?
Common bile duct
Which loop of the liver is the largest?
Right loop
What is found in the liver porta?
Hepatic artery
Hepatic portal Wvein
Hepatic duct
What are most of the tissues of the liver encapsulated by?
Glason capsule
What us glason capsule made of?
Connective tissue
What is the role of glason capsule?
Protects the liver and keeps the position of the liver stable
Which are the cells which do most in the liver?
Hepatocytes
Are hepatocytes polar or non-polar?
Polar
What are sinusoids?
Capillaries of the liver
What are the parenchymal cells of the liver?
*Parachymal=take up most volume
Hepatocytes
What are the non-parenchymal cells of the liver?
Pit cells
Kupffer cells
Liver sinusoidal endothelial cells
Hepatic stellate cells
What are found between hepatocytes?
Bile canaliculi
Which organ stores bile?
Gallbladder
What do hepatic stellate cells do?
Store vitamin A
When do hepatic stellate cells become activated?
If there is any virus or infection
What do hepatic stellate cells secrete?
Fibrogenic material, like collagen
What happens if the hepatic stellate cells continuously produce fibrogenic material?
May lead to fibrosis or cirrhosis of the liver
What are Kupffer cells?
Macrophages of the liver
What are the pit cells?
Natural killer cells of the liver
How many supplies of blood come to the liver?
Two
Describe where the two supplies of blood for the liver come from.
One comes from the portal vein which brings blood from the alimentary tract.
The other comes from the hepatic artery from the aorta.
Describe the blood which comes from the portal vein compared to the blood which comes from the hepatic artery.
Portal vein- rich in nutrients but deoxygenated
Hepatic artery- rich in oxygen
Where in the liver will the two blood supplies mix?
Sinusoid
How will the blood leave the liver?
By the central vein
How does the liver act as a sieve?
Filters the blood from any toxins that come from the portal vein
What are changliocytes?
Biliary epithelial cells
What is septa?
Branches of connective tissue which help support the liver
What do the septa divide the liver into?
Hexagonol lobules
What is located at each corner of a hexagonal lobule?
Portal triad (hepatic portal vein, hepatic artery, hepatic duct) as well as nerves and lymph vessels
What is at the centre of each lobule?
Central vein
What does the central vein do?
Drains the blood to the hepatic vein and then to the IVC
Which structures radiate out from the central veins?
Hepatic cords
What are hepatic cords composed of?
Hepatocytes
What do bile canaliculus do?
Transport bile from liver to bile ducts
Which direction does blood move compared to bile?
Blood moves from the portal triad to the central vein.
Bile moves from the central vein to the portal triad.
What are the main functions of the liver?
hehe there’s a lot, have fun x
-Metabolism of xenobiotics
-Metabolism of bilirubin
-Synthesis of carbs/lipids/amino acids/proteins/bile acids/hormones/blood clotting factors
-Clearance of toxins and pathogens
-Immune response regulation
What is the alimentary role of the liver?
To produce and secrete bile
What are the six components of bile?
- Bile acids
- Lecithin
- Cholesterol
- Bile pigments
- Toxic metals
- Bicarbonate
What happens to the toxic metals in bile?
Detoxified in liver
What is the bile pigment?
Bilirubin from haemoglobin
Which three components are synthesised in the liver and have the role of solubilising fat?
Bile acids
Lecithin
Cholesterol
What is the role of bicarbonate in bile?
Neutralisation of acidic chyme
Five of the components of bile are secreted by hepatocytes. Which one is secreted by duct cells?
Bicarbonate
What is bilirubin?
Breakdown product of haemoglobin from old/damaged erythrocytes (RBC’s)
What colour does bilirubin turn bile?
Yellow
When bilirubin is in the intestine, it is modified by a bacterial enzyme. What colour pigment does this form?
Brown
What does the brown pigment do?
Makes faeces brown
Some bilirubin can be reabsorbed back into blood. What does this do?
Turns urine yellow
What helps with the synthesis of bile in the liver?
Cholesterol
Which molecules could bile acids be joined to before secreion?
Glycine or taurine
What are bile acids known as before secretion when they are conjugated with taurine or glycine?
Bile salts
Why are bile salts conjugated to something else?
To increase solubility
How are secreted bile salts recylced?
Via enteropatic circulation
When bile salts are secreted into the hepatic duct, it has two options. Explain them.
- Go through common bile duct and get secreted into the duodenum
- If sphincter is closed, go back to the gallbladder where it will be stored and concentrated
When happens when bile salts get into the intestine?
Bacteria degrade the bile salts
What % of bile salts are recycled?
95%
Remaining 5% excreted in faeces
Where is the gallbladder located?
Inferior surface of liver
What are the three layers of the gallbladder?
Mucosa
Muscularis
Serosa
Describe the mucosa layer of the gallbladder.
Folded and has rugae which allows for expansion
Describe the muscularis layer of the gallbladder.
Smooth muscle which is responsible for contraction
What type of tissue is the serosa?
Connective tissue
Explain the pathway of bile.
Gallbladder -> cystic duct -> common bile duct
What controls the secretion of bile and pancreatic juice into the duodenum?
Sphincter of Oddi
What happens when the sphincter of Oddi is closed?
Bile forced back to gallbladder
How much does the gallbladder concentrate bile?
5-20 times
How does the gallbladder make the bile more concentrated?
Absorbs sodium and water
What gets released if there is fat in the duodenum?
CCK
What does CCK do to the sphincter of Oddi?
Relaxes it, allowing it to release more bile and pancreatic juices
RECAP- what gets released if there is acid in the duodenum?
Secretin
RECAP- what does secretin do?
Decrease gastric acid secretion and emptying rate
Increase bicarbonate secretion.
RECAP- what does CCK do?
Decreases gastric acid emptying
Increases pancreatic enzyme secretion to digest fat
