The Liver Flashcards
How many supplies of blood does the liver have? (1 mark)
2
What does the hepatic vein do? (2 marks)
Returns deoxygenated blood from the liver to the heart,
through the inferior vena cava.
What are the two blood supplies of the liver? (2 marks)
Hepatic portal vein
Hepatic artery
What does the hepatic artery do? (2 marks)
Supplies oxygenated blood to the liver from the aorta.
What does the hepatic portal vein do? (2 marks)
Supplies deoxygenated blood to the liver from the digestive system.
Why does the liver have two supplies of blood? (5 marks)
One from the aorta- provides oxygen
One form the digestive system- to allow the liver to remove excess or unwanted substances from the blood and return substances to the blood to ensure concentrations are maintained.
State two differences between the blood carried in the hepatic artery and the blood carried in the hepatic portal vein. (4 marks)
Pressure:
High pressure in the hepatic artery.
Low pressure in the hepatic portal vein.
Concentrations:
High concentration of oxygen in the hepatic artery.
High concentration of products of digestion in the hepatic portal vein.
What are liver cells called? (1 mark)
Hepatocytes
What happens in the sinusoids? (2 marks)
Blood from the hepatic artery and hepatic portal vein mix.
Describe 5 adaptations of sinusoids. (5 marks)
Lined with hepatocytes
Walls are very porous/ many pores between cells
One layer of very thin cells
No basement membrane
Wider than capillaries (slower blood flow)
How is bile discharged into the small intestine? (1 mark)
Via the bile duct
Name three things that bile contains. (3 marks)
Hydrogen carbonate ions
Bile salts
Pigments
Name two pigments that bile contains (2 marks)
Bilirubin
Biliverdin
Describe the pathway that bile goes through to be stored in the gall bladder. (3 marks)
Secreted by the hepatocytes
into the canaliculi
And drains into the gall bladder
How does the gall bladder make bile more concentrated? (1 mark)
By water reabsorption
What is cirrhosis? (1 mark)
The scarring of the liver caused by excessive alcohol consumption.
What do kupffer cells do? (1 mark)
They break down blood cells to release haemoglobin for recycling.
What is haem broken down into? (2 marks)
Bilirubin and biliverdin, which are excepted as part of bile.
State 7 functions of the liver. (7 marks)
- Control of blood glucose
- Synthesis of bile
- Synthesis of red blood cells in the fetus
- Storage of vitamins
- Detoxification of alcohol and drugs
- Break down of hormones
- Destruction of red blood cells
What enzyme converts hydrogen peroxide into water and oxygen? (1 mark)
Catalase
What does catalase break down, and what into? (3 marks)
Hydrogen peroxide into water and oxygen.
What enzyme breaks down drugs? (1 mark)
Cytochrome P450
What does Cytochrome P450 break down? (1 mark)
Drugs
What enzyme breaks down ethanol? (1 mark)
Ethanol dehydrogenase
What enzyme breaks down ethanal? (1 mark)
Ethanal dehydrogenase
What does ethanol dehydrogenase break down ethanol into? (1 mark)
Ethanal and two hydrogens
What does ethanal dehydrogenase break down ethanal into? (1 mark)
Ethanoic acid and two hydrogens
When alcohol is broken down, hydrogen atoms are released, what happens to these? (1 mark)
They get combined with NAD to produce NADH.
How can drinking too much alcohol lead to a fatty liver? (4 marks)
NAD combines with the hydrogen released, meaning it cannot be used to breakdown fatty acids to use in respiration. This results in the fatty acids being converted back into lipids and being stored in hepatocytes.
What is the ornithine cycle? (1 mark)
The way the liver processes amino acids.
