Liver and gall bladder function Flashcards
What are the different functions of the liver
Bile production
Metabolism
Detoxification of the blood
What is the blood supply of the liver
30% of the blood is oxygenated and comes from the hepatic artery which originates from the coeliac artery
70% of the blood is deoxygenated and comes from the superior and inferior mesenteric arteries which supply blood to the intestines and pancreas. The blood from pancreas and intestines then drain into portal vein and that goes to liver
What vein drains the liver
Hepatic vein
How are endothelial cells adapted in the liver
Spaces between endothelial cells that lie hepatic sinusoids are large so in liver, blood that comes into these cells come into contact more easily with liver cells
Where are bile canals in the liver
On other side of hepatocytes there are bile canals and hepatocytes secrete stuff into bile canals
What are the major secretions of hepatocytes into bile ducts
Bile salts Phospholipids (lecithin) Bile pigment (bilirubin) Cholesterol Inorganic ions
What is enterohepatic recycling
Bile salts get recycled
- Some are stored in gallbladder
- Bile salts come into duodenum to emulsify fat. They then pass into small intestine and we actively reabsorb the bile salts in the ilium.
- Travels via portal venous system so it goes back to liver
What are major breakdowns of haemoglobin
Bile salts
How is bilirubin removed from the body
1) RBCs broken down.
2) haemoglobin broken down into bilirubin
3) Albumin transports it to liver where hepatocytes combine it with glucorinic acid to become bilirubin glucuronide
4) Goes into small intestine and ends up in faeces (pale stools indicate a lack of bilirubin)
5) Some bacteria break it back down into bilirubin and forms H2 and urobilinogen
6) Some excreted as urine but some delivered back to liver and goes into hepatic veins and kidney
Under normal conditions, what is the flow to the duodenum prevented by and what does this mean
Closure of the Sphincter of Oddi. Bile enters gall bladder
What relaxes the Sphincter of Oddi
After a meal, CCK is released in response to presence of fat in duodenum. Neural influences also relax it
metabolism role of liver
Liver converts fructose and galactose to glucose
- Large portion of glucose is taken up into liver and converted to glycogen or TAG
- Fats combine with protein fraction and released as lipoproteins
What does the liver synthesise and so what tests can be done to test liver function
Plasma proteins (albumin) Clotting factors
–> protein conc of blood decreased and so can’t hold water and so this causes ascites
–> Bleeding time is also increased so can check the INR
What is the detoxification function of the liver
Generally increases water solubility
What endogenous things does the liver remove and therefore how does this present if they are unable to get removed
INsulin, glucagon, aldosterone, female sex hormones
–> therefore in males, the build up of female sex hormones means they start to display female characteristics
What exogenous things does the liver remove
Drugs
What is a telltale sign of liver failure
Jaundice
Why does jaundice occur and how to treat it
Bilirubin accumulation in plasma
-Treat with light which breaks down pigment
Different causes of jaundice
Haemolytic jaundice
Intrahepatic jaundice
Obstructive jaundice
Physiological jaundice of the new born
What is haemolytic jaundice
Excessive haemolysis of red red blood cells (overwhelms liver capacity for excretion of bilirubin)
What is intrahepatic jaundice
Defect in uptake or conjugation or secretion of bilirubin by hepatic cells (common in acute hepatitis)
What is obstructive jaundice
Blockage of bile ducts
What is physiological jaundice of the newborn
Babies have a poor capacity for conjugating bilirubin
What is hepatitis
Infection/inflammation of the liver
What is the cause of acute hepatitis
Viral infections - Hepatitis A,B,C
Drugs eg paracetamol
Cause of chronic hepatitis
Viral infections - Hepatitis B,C
Cause of cirrhosis and treatment
Necrosis of liver cells
Major causes: alcohol, Hepatitis B,C
–>No reversing treatment. Stop causative effect. Otherwise transplantation
