Week 2.9 - Liver Structure and Function

Question 1

What is the liver? weight? significance?

Answer 1

• largest organ
• endocrine and exocrine
• 2-3% of body weight

Question 2

How many lobes are in the liver and what are their names?

Answer 2

4. 2 major - left and right (largest). 2 minor - Caudate and quadrate lobes

Question 3

How many ligaments are in the liver?

Answer 3

falciform ligament between left and right lobe.
round ligament on inferior margin

Question 4

What and where is the porta?

Answer 4

inferior surface of liver. all connections leave liver - hepatic portal vein, hepatic artery, hepatic duct and hepatic nerve plexus

Question 5

What are hepatocytes?

Answer 5

parenchymal cells in the liver responsible for many major roles

Question 6

Where do we find bile canaliculi? journey of bile?

Answer 6

between the hepatocyte cells, secreted at bile duct through cholangiocytes and into the common hepatic duct

Question 7

What are liver sinusoid endothelial cells?

Answer 7

for sinusoid - capillaries of the liver.

Question 8

what are hepatic stellate cells?

Answer 8

store vitamin A and upon liver damage are responsible for releasing fibrogenic materials like collagen to make the liver fibrous

Question 9

What are kupffer cells and pit cells?

Answer 9

kupffer cells are macrophages of the liver. pit cells are natural killer cells of the liver.
both used to detoxify the blood with sinusoids.

Question 10

What is the dual blood supply of the liver?

Answer 10

hepatic portal vein with rich nutrients but poor O2

hepatic artery with poor nutrients but rich O2

Question 11

How do these blood vessels run through the liver?

Answer 11

start at portal triad in a lobule. hepatic portal vein and hepatic artery run from triad towards central vein. between they mix in the sinusoid (capillaries) where materials are collected and blood is detoxified

Question 12

What is a hepatic functional unit made up of?

Answer 12

hepatic lobule - 6 portal triads of hepatic portal vein, hepatic artery and bile duct. hepatocytes run in cords towards the central vein. sinusoids are between the hepatocytes.

Question 13

Where does bile run in a lobule?

Answer 13

from central vein towards the portal triad bile duct

Question 14

Where does the central vein lead?

Answer 14

toward hepatic veins then to IVC

Question 15

What are hepatocytes used for?

Answer 15

• storage of nutrients
• bile synthesis
• metabolise drugs to make them water soluble so they can enter blood

Question 16

What is the histology of the liver?

Answer 16

• covered by connective tissue capsule and visceral peritoneum. except bare area, which has no connective tissue but instead surrounded by coronary ligament.
• at porta there is connective tissue capsule with septa - divides liver into hexagonal lobules.

Question 17

What are the main functions of the liver?

Answer 17

• regulation of immune system
• removes toxins and pathogens
• metabolism of xenobiotics and biliruben
• synthesis of carbs, lipids, amino acids, proteins, bile acids, hormones, blood clotting factors

Question 18

what is the alimentary role of the liver?

Answer 18

production and secretion of bile