Liver Structure and Function

Question 1

Which lobe of the liver is larger and why?

Answer 1

Right

Question 2

What are the names of the two minor lobes?

Answer 2

Caudate and quadrate

Question 3

What is the aorta of the liver?

Answer 3

Entry and exit of blood vessels, lymphatic vessels, ducts and nerves (it is surrounded by ligamentous tissue)

Question 4

What is the falciform ligament?

Answer 4

Attaches liver to anterior body wall (becomes round ligament)

Question 5

What is the liver covered by?

Answer 5

Connective tissue capsule and visceral peritoneum except for the bare area

Question 6

What is the bare area of the liver?

Answer 6

Small area on diaphragmatic surface surrounded by coronary ligament

Question 7

What is the name of the part of the connective tissue capsule that extends into the liver?

Answer 7

Septa - branching network of septa (walls) that go in-between the hepatocytes and then divides them into hexagonal lobules

Question 8

What structures follow the septa?

Answer 8

Vessels, lymphatic ducts and nerves

Question 9

What is the portal triad?

Answer 9

At the corner of each hexagonal lobule which consists of the hepatic portal artery, hepatic duct and hepatic vein

Question 10

How does blood drain back through the liver to the main circulation?

Answer 10

Blood from the portal triad -> sinusoids -> central vein (middle of each lobule) -> hepatic veins -> IVC

Question 11

What are hepatic cords and what lies between them?

Answer 11

Radiate out from central veins, which are composed of hepatocytes and have bile canaliculi and sinusoids between cells

Question 12

What are hepatic sinusoids?

Answer 12

Spaces between the hepatic cords which are discontinued (fenestrated) capillaries

Question 13

What is the role of the hepatocytes?

Answer 13

Bile synthesis (travel through bile canaliculi -> hepatic ducts)
Nutrient storage (glycogen, fats, Vits (B12, A, D, E, K), Cu, Fe)
Nutrient interconversion
Detoxification

Question 14

What type of blood travels through the hepatic portal vein?

Answer 14

Deoxygenated, nutrient rich blood from the gut

Question 15

What type of blood travels through the hepatic artery?

Answer 15

Well oxygenated blood from the coeliac branch of the aorta

Question 16

What are the 6 components of bile?

Answer 16

1. Bile acids
2. Lecithin
3. Cholesterol
4. Bile pigments (bilirubin)
5. Toxic metals (detoxified in liver)
6. Bicarbonate

Question 17

What 2 of the 6 components of bile are amphiphatic molecules for emulsification?

Answer 17

Bile acids and lecithin - solubilise fat

Question 18

How are bile pigments formed?

Answer 18

Bilirubin formed through the breakdown products of haemoglobin from old/damaged erythrocytes

Question 19

Where is bile synthesised?

Answer 19

In the liver from cholesterol: before secretion into the hepatic duct, bile acids conjugate with glycine or tourine -> bile salts

Question 20

How are bile salts recycled?

Answer 20

Enterohepatic circulation

Question 21

What are the three layers of the gallbladder wall?

Answer 21

Mucosa (with rugae for expansion)
Muscularis (smooth muscle) -> contraction
Serosa (connective tissue)

Question 22

What is the function of the sphincter of oddi?

Answer 22

Controls release of bile and pancreatic juice into the duodenum

Fat in duodenum -> CCK from intestinal cells released -> stimulates sphincter of oddi to relax and gallbladder to contract (to release bile)

Question 23

What is the role of the gallbladder?

Answer 23

Stores bile and concentrates bile 5-20 times by absorbing Na and H2O