Liver A+P

Question 1

why is zone 1 of the liver best perfused and first to regenerate?

Answer 1

oxidative metabolism (beta-oxidation, gluconeogenesis, bile formation, amino acid catabolism) – best access to blood and nutrients

Question 2

why is zone III got the lowest perfusion?

Answer 2

due to to distance to portal triad and largest role in detoxification, biotransformation of drugs, ketogenesis, glycolysis, lipogenesis, glutamine formation

Question 3

what does the bile canaliculi do?

Answer 3

more surface area for collection

Question 4

where is the space of disse?

Answer 4

pace between sinusoidal lumen and surrounding basolateral membrane

Question 5

what does the space of disse contain?

Answer 5

• Contains microvilli to communicate with capillary
• Contains collagen and other proteins to maintain scaffolding
  kuppler cells
  stellate cells

Question 6

what do kuppler cells do?

Answer 6

contain macrophages

Question 7

what do Ito or stellate cells do?

Answer 7

fat stores - vit A
can aid in regeneration of liver

Question 8

what roles does the liver have?

Answer 8

• Storage for fat soluble vitamins
• Controls cholesterol homeostasis
• Stores iron and copper
• Iron homeostasis (hepcidin)
• Protein synthesis
• Heme breakdown into unconjugated bilirubin and conjugates it
• Sex hormone metabolism
• Carrier protein reproduction and development
• Kupffer and pit cells – immunological

Question 9

what does bile do to aid kidneys?

Answer 9

helps excrete materials kidneys could not

Question 10

what is the function of bile?

Answer 10

• Aids in absorption and digestion of lipids via secretion of bile salts and acids

Question 11

where can bile end up?

Answer 11

• Bile secreted into bile canaliculi goes into smaller ducts and then ends up in duodenum or being stored in gall bladder for storage and concentration determined by duct and spinchter of Oddi pressures

Question 12

where do fat-soluble vitamins get absorbed?

Answer 12

most fat soluble vitamins reach liver via intestinal absorption in form of chylomicrons of VLDL

Question 13

how is bilirubin metabolised?

Answer 13

liver involved in breakdown of heme. Haemolysis occurs in spleen, liver and bone marrow. Heme is broken down into eventually unconjugated bilirubin. Liver receives unconjugated bilirubin bound to albumin from circulation. The unconjugated bilirubin becomes hydrophilic and then is conjugated – can dissolve in bile and excreted with faeces

Question 14

where is the site of deiodination from T4 to T3?

Answer 14

liver

Question 15

what plasma proteins does the liver synthase?

Answer 15

The liver manages the synthesis of nearly every plasma protein in the body including albumin, binding globulins, protein C, protein S and all clotting factors except factor XIII

Question 16

where does liver receive blood from?

Answer 16

• Hepatic portal vein: (2/3 of total) – carries venous blood form intestine, pancreas and spleen
• Hepatic artery carries remaining 1/3 and brings oxygenated blood to liver

Question 17

what is the portal triad?

Answer 17

common hepatic artery, common bile duct and portal vein

Question 18

what cells are liver parenchyma made up of?

Answer 18

hepatocytes

Question 19

what is the stroma of the liver?

Answer 19

continuation of surrounding capsule of Glisson – contains connective tissue and blood vessels