Liver

Question 1

What are the functions of the liver ?

Answer 1

• manufactures bile
• controls levels of fats, amino acids & glucose
• cholesterol synthesis
• storing iron & vitamins
• neutralising/destorying drugs & toxins

Question 2

Describe bile synthesis & function

Answer 2

• produced in the liver
• stored in the gallbladder
• aids in digestion, absorption of fats & excretion

Question 3

What is the composition of bile?

Answer 3

• bile salts
• phospholipids
• cholesterol
• bile pigments (bilirubin)

Question 4

Describe the role of the liver in metabolism of nutrients

Answer 4

• receives digestive products in the form of glucose, amino acids, fatty acids and glycerol
• metabolic end products are often stored in the liver & utilised at a later stage
• hepatocytes deal with nutrients depending on whether its in abundance or not

Question 5

Describe the role of the liver in cholesterol synthesis

Answer 5

• produces cholesterol
• delivers it to cells around the body that need it
• it also removes cholesterol by converting it to bile salts

Question 6

What are the livers 3 main functions in iron homeostasis ?

Answer 6

1. its the main site of iron storage
2. regulates iron traffic into and around the body through its production of peptide hepcidin
3. site of synthesis of major proteins of iron metabolism

Question 7

Define ferritin

Answer 7

• stores iron, representing iron status

Question 8

Define hepcidin

Answer 8

• binds to ferroportin, thereby inhibiting iron absorption/efflux

Question 9

Where is the liver located ?

Answer 9

• in the upper right hand portion of the abdominal cavity, beneath the diaphragm & on top of the stomach

Question 10

Describe the structure of the liver

Answer 10

• made of 2 lobes - right & left
• each lobe consists of thousands of liver lobules
• in each liver lobule there are several portal triads

Question 11

Describe the structure of a portal triad

Answer 11

• consists of 5 structures
  1. proper hepatic artery
  2. hepatic portal vein
  3.1/2 small bile ductules
  4. lymphatic vessels
  5. branch of the vagus nerve

Question 12

Describe the proper hepatic artery

Answer 12

• an arteriole branch of the hepatic artery that supplies oxygen

Question 13

Describe the hepatic portal vein

Answer 13

a venue branch of the portal vein, with blood rich in nutrients but low in oxygen

Question 14

Describe the ductules found in the portal triad

Answer 14

• 1/2 small ductules from the cuboidal epithelium, branches of the bile conducting system

Question 15

What are the percentages of different liver cells ?

Answer 15

80% = hepatocytes
10% = hepatic stellate cells
10% = rest of cells –> Kuppfer cells, endothelial cells