Excretion, homeostasis and the liver

Question 1

What are the three main waste products in mammals?

Answer 1

1) Carbon dioxide
- Waste product of cellular respiration

2) Bile pigments
- Formed from the breakdown of haemoglobin from old red blood cells in the liver
- Excreted in the bile from the liver into the small intestine through the bile duct

3) Nitrogenous waste products (urea)
- Formed from the breakdown of excess amino acids by the liver

Question 2

What is oxygenated blood supplied to the liver through?

Answer 2

The hepatic artery

The hepatic portal vein

Question 3

What is deoxygenated blood removed from the liver in and returned to the heart?

Answer 3

The hepatic vein

Question 4

What does the hepatic portal vein carry and where from?

Answer 4

Carries blood loaded with nutrients from the intestines

Question 5

What are liver cells called?

Answer 5

Hepatocytes

Question 6

What is blood from the hepatic portal vein and hepatic artery mixed in?

Answer 6

Sinusoids

Question 7

What are sinusoids surrounded by?

Answer 7

Hepatocytes

They get their oxygen from the blood that is being mixed in the sinusoids

Question 8

What do Kupffer cells act as?

Answer 8

Macrophage

Ingesting foreign particles and helping the liver remain free from disease

Question 9

What do hepatocytes secrete and where?

Answer 9

Bile into the canaliculi which takes the bile to the gall bladder

Question 10

What are the three functions of the liver?

Answer 10

1) Carbohydrate metabolism
- Hepatocytes are stimulated by insulin to convert glucose into glycogen
- Glucagon causes hepatocytes to convert glucose into glycogen

2) Deamination of excess amino acids
3) Detoxification

Question 11

Outline the deamination of excess amino acids

Answer 11

1) Remove the amine group converting, it into ammonia then to urea

Question 12

What cells allows transamination to occur?

Answer 12

Hepatocytes