The liver

Question 1

What delivers oxygenated blood to the liver?

Answer 1

The hepatic artery delivers blood from the aorta

Question 2

How does blood leave the liver?

Answer 2

leaves via the hepatic vein which rejoins with the vena cava and return the blood to the bids normal circulation

Question 3

What does the hepatic portal vein do?

Answer 3

delivers deoxygenated blood from the digestive system to the liver

Question 4

what does the bile duct do?

Answer 4

carries bile that has been secreted from the liver into the gall bladder

Question 5

what is the function of bile?

Answer 5

bile is stored in the gall bladder until it is needed to aid the digestion of fats in the small intenstines

Question 6

what is the liver divided in to?

Answer 6

lobes which are divided into lobules which are a cylindrical shape

Question 7

What passes through a sinusoid?

Answer 7

Blood from the hepatic artery and portal vein is mixed and passes along the chamber of the sinusoid

Question 8

What are kupfer cells and what do they do?

Answer 8

these are specialised macrophages which move about within the sinusoids. They engulf foreign particles and recycle old red blood cells

Question 9

What are the 3 functions of the liver?

Answer 9

1. storage of glycogen
2. detoxification
3. formation of urea

Question 10

How is glycogen stored in the liver?

Answer 10

tje liver stores the glycogen in granules in the cytoplasm of the liver cells (hepatocytes). these can be broken down into glucose which can be released into the blood to control blood glucose concentration

Question 11

What is detoxification?

Answer 11

this is the neutralisation and breakdown of unwanted chemical which may cause harm for example hydrogen peroxide and alcohol

Question 12

What are the steps of alcohol detoxification?

Answer 12

1. ethanol (alcohol) is broken down by ethanol dehydrogenase into ethanal
2. further dehydrogenated by the enzyme ethanal dehydrogenase which produced acetate
3. acetate combines with coenzyme A to form acetyl coenzyme A

Question 13

Why can excess amino acids not be stored?

Answer 13

the amino group makes them toxic

Question 14

what is deamination?

Answer 14

this is when the amine group is removed from the amino acid which converts it into ammonia

Question 15

what are the properties of ammonia?

Answer 15

highly soluble and highly toxic so it needs to be converted to urea

Question 16

what cycle converts ammonia to urea?

Answer 16

ornithine cycle

Question 17

Summarise the ornithine cycle?

Answer 17

ammonia and carbon dioxide combine with ornithine to produce citruiline, this is then converted to arginine which is converted to ornithine by the removal of urea

Question 18

What are the properties of urea?

Answer 18

less soluble and less toxic than ammonia, can be passed back into the blood and transported around the body to the kidney