D3 Liver

Question 1

Where does the liver recieve oxygenated blood from?

Answer 1

Hepatic artery

Question 2

Where does the liver send deoxygenated blood from?

Answer 2

Hepatic artery

Question 3

Where does the liver send deoxygenated blood back to the heart through?

Answer 3

Hepatic vein

Question 4

What is the function of the liver?

Answer 4

Responsible for storage and release of key nutrients
Responsible for detoxification of harmful substances
Produces plasma proteins to maintain stable osmotic conditions in the blood
Breakdown of red blood cells
Produces bile salts

Question 5

What hexagonal histological structures is the liver made of?

Answer 5

Lobules

Question 6

Describe different elements of a lobule

Answer 6

Has a central vein which feeds into the hepatic vein
Contains hepatocytes throughout
Has bile ducts
Has hepatic artery branches
Has branches of the portal vein

Question 7

Where do the hepatic artery and portal vein branches in the lobules drain towards?

Answer 7

Sinusoids which exchange materials with the hepatocytes and drain into the central vein

Question 8

What effect does glucagon have on the liver?

Answer 8

Causes the liver to breakdown glycogen into glucose and export it to the body

Question 9

What effect does insulin have on the liver?

Answer 9

Causes the liver to take up glucose and store it as glycogen

Question 10

What happens if the hepatic glucagon stores are depleted?

Answer 10

Liver synthesises glucose from other sources

Question 11

What is the role of the liver in amino acid metabolism?

Answer 11

Removes the potentially toxic amine group and converts it into a harmless product (urea) which is excreted via the kidneys

Question 12

Define transaminiation

Answer 12

The process by which the liver synthesises non-essential amino acids from surplus stock

Question 13

What is the role of the liver in fat metabolism?

Answer 13

Converts excess carbohydrates and proteins into fatty acids and triglycerides and synthesises phospholipids and cholesterol

Question 14

What is LDL?

Answer 14

Low density lipoprotein which transports cholesterol to body cells

Question 15

What is HDL?

Answer 15

High density lipoprotein which transports cholesterol back to the liver wither for storage or conversion

Question 16

What are bile salts made from?

Answer 16

Surplus cholesterol

Question 17

Where is excess bile stored?

Answer 17

Gall bladder

Question 18

What are the two steps of detoxification by the liver?

Answer 18

Toxins converted into less harmful chemical
Converted chemical attached to another substance

Question 19

What enzyme aids in the detoxification of harmful chemicals in the liver?

Answer 19

Cytochrome P450

Question 20

Why are compounds of converted chemicals which are no longer toxic usually attached to another system by the liver?

Answer 20

To increase the solubility to allow excretion through the kidney

Question 21

What are plasma proteins?

Answer 21

Proteins present in the bloodstream and produced by the liver (except immunoglobulins)

Question 22

What produces plasma proteins?

Answer 22

The rough ER of hepatocytes (they are then exported by the Golgi complex)

Question 23

What is the function of albumin?

Answer 23

Regulate osmotic pressure

Question 24

What is the function of globulins?

Answer 24

Participate in the immune system and can act as transport proteins

Question 25

What is the function of fibrinogens?

Answer 25

Involved in clotting

Question 26

Why is the lifespan of erythrocytes short?

Answer 26

Lack of nucleus

Question 27

Describe the breakdown of erythrocytes and haemoglobin recycling

Answer 27

Kupffer cells engulf red blood cells via phagocytosis and break down the haemoglobin into the globin and heme groups
Globin is digested to produce amino acids (for recycling or metabolism)
Heme group is broken down into bile pigment

Question 28

What happens to the iron in the heme group during recycling?

Answer 28

It can either be stored in the liver as ferritin or be transported to the bone marrow for new erythrocytes

Question 29

What causes jaundice?

Answer 29

Bilirubin excess in the body which leaks into the body

Question 30

What can cause bilirubin excess?

Answer 30

Liver disease (impaired removal)
Obstruction of the gall bladder (prevents the secretion of bile)
Damage to red blood cells (increased erythrocyte destruction)