Structure and function of then liver

Question 1

Blood supply

Answer 1

Input: portal vein:75% hepatic artey: 25%

output= hepatic vein

Question 2

Bile formation

Answer 2

libver: from cholesterol- hydroxylation, then conjugated glycine or taurine–> hydrophillic tail –> ampipathic 4 ringed structure

Question 3

Cholestryamine

Answer 3

prevents recirculation bile salts –> decreases blood cholesterol as more salts are made

Question 4

Detoxification xenobiotics

Answer 4

Phase1: oxidation, hydroxylation, hydrolysis and reduction = catabolic –> more reactive hydrophillic substances. By cytochrome P450 enzymes (CYP1,CYP2,CYP3} non-specific) in SER
Phase 2: conjugation

Question 5

Haem breakdown

Answer 5

Haem –> billiverdin (kupffer cells) –> bilirubin (hepatocytes), conjufated and attached to albumin –> urobilinogen in gut. Excreted as urobilin and sterocobilin

Question 6

Pre-hepatic jaundice

Answer 6

before haem broken down- haemolytic anaemia e.g. sickle cell

Question 7

intrahepatic jaundice

Answer 7

liver damage, inherited Gilbert’s syndrome

Question 8

extra hepatic jaundice

Answer 8

blockage e.g. gallstones

Question 9

Alcohol metabolism

Answer 9

If levels V high then P450 enzymes
if not: ethanol –> acetaldehyde (alcohol dehydrogenase, cytosol) –> acetate (acetaldehyde dehyrdrogenase, mitochondria)
Acetate –> acetyl CoA–> krebs cycle –> ATP} explains calories
Lots NADH produced