Liver function

Question 1

three blood vessels associated with the liver

Answer 1

portal vein - carries nutrient rich blood from the gut,
- prevents glucose entering the general circulation by converting it to glycogen
-helps maintain osmotic potential of blood
- allows toxins to be removed

It is responsible for the breakdown of red blood cells and the production of bile salts

hepatic artery - receives oxygenated blood
hepatic vein - deoxygentaed blood is carried away from the liver

Question 2

Explain the importance of bilirubin in the onset of jaundice. [4]

Answer 2

• comes from breakdown of red blood cells
• results from the breakdown of the heme group of hemoglobin
• normally excreted with bile

-released into blood when excess is produced or bile duct blocked

• jaundice is a yellowish pigmentation of the skin/whites of eyes caused by high levels of bilirubin in blood/tissues
• it is often observed in newborns as they have an immature liver which does not keep up with excreting bilirubin
• jaundice is often seen in liver disease such as liver cancer/chronic alcoholism

Question 3

compare and contrast the structure of cappilaries and sinusoids

Answer 3

a. sinusoids have open pores/fenestrations and capillary does not contain fenestrations

b. Kupffer cells are located inside sinusoids but not in capillaries

c. sinusoids larger in diameter than capillaries

• both are one cell thick
• both have a basement membrane;

Question 4

what does liver do with excess aminoacids?

Answer 4

it removes toxic amine group (-NH2) from the breakdown of aminoacids
converts it into urea

Question 5

list the functions of the liver

Answer 5

• detoxification (by converting into less harmful substance (alcohol, -NH2) or (making substance water soluble by attaching it to another substance)
• storage of nutrients (vitamin A, D, glycogen, iron)
• control of blood glucose levels
• synthesis of cholesterol
• conversion of cholesterol into bile salts
• production of bile
• breakdown of erythrocytes
• produce plasma proteins ( proteins in the blood such as albumin which regulate osmotic potential of blood)

Question 6

outline the breakdown of erythrocytes in the liver

Answer 6

• Kuppfer cells engulf erythrocytes and break them down into heme group and globin
• globin broken down into aminacids metabolised by the liver
• heme group broken down into bilirubin and iron
• iron either stored in the liver or transported to bone marrow
• bilirubin used to make bile