The liver

Question 1

How is blood supplied to the liver?

Answer 1

via the hepatic artery and hepatic portal vein

Question 2

Which vessel carries blood loaded with products of digestion from the intestine to the liver?

Answer 2

hepatic portal vein

Question 3

What are liver cells called?

Answer 3

hepatocytes

Question 4

What are specific features of hepatocytes?

Answer 4

large nuclei, prominent golgi apparatus and lots of mitochondria

Question 5

What is a sinusoid?

Answer 5

spaces in the liver tissue surrounded by hepatocytes where blood from hepatic artery and hepatic portal vein mix

Question 6

What are sinusoids surrounded by?

Answer 6

hepatocytes

Question 7

What other cells do the sinusoids contain?

Answer 7

kupffer cells

Question 8

What is the role of kupffer cells?

Answer 8

they act as resident macrophages to the liver by ingesting foreign particles and helping protect against disease

Question 9

What do the hepatocytes secrete and where does it go?

Answer 9

bile secreted into spaces called canaliculi where it drains into bile duct which takes it to the gall bladder

Question 10

What is bile made from?

Answer 10

the breakdown of blood

Question 11

What are the three main functions of the liver?

Answer 11

deamination of excess amino acids, detoxification and carbohydrate metabolism

Question 12

How does the liver control blood glucose levels?

Answer 12

rise in insulin levels cause hepatocytes to convert glucose to glycogen to be stored and vice versa with glucagon

Question 13

What is transamination?

Answer 13

the conversion of one amino acid to another

Question 14

Why is transamination important and which cells do it?

Answer 14

important because our diet doesn’t always contain the required balance of amino acids so they can be changed by the hepatocytes

Question 15

What is deamination?

Answer 15

the removal of the amine group from excess amino acids

Question 16

Why is deamination important?

Answer 16

the body cannot store proteins or amino acids so excess is excreted which is a waste

Question 17

What happens to the amine group in deamination?

Answer 17

converted to ammonia then to urea which is excreted by the kidneys

Question 18

Briefly describe the ornithine cycle?

Answer 18

series of reactions converting ammonia to urea. ammonia + CO2 gives citruline. citruline converts to arginine which loses water to turn into urea

Question 19

How is hydrogen peroxide broken down?

Answer 19

hepatocytes contain the enzyme catalase which splits hydrogen peroxide into water and oxygen

Question 20

How does the liver detoxify ethanol?

Answer 20

hepatocytes contain alcohol dehydrogenase which breaks down ethanol into ethanal which is converted into ethanoate which can be used to build up fatty acids or used in respiration

Question 21

Which two important enzymes for detoxification do hepatocytes contain?

Answer 21

alcohol dehydrogenase and catalase