Structure and Function of the Liver

Question 1

Names the major and minor lobes of the liver

Answer 1

Right & Left (major)

Caudate & Quadrate (minor)

Question 2

Location of the Liver

Answer 2

Right hypogastrium and epigastric areas, extending into the left hypogastrium

Question 3

Is the liver completely peritonised ?

Answer 3

The posterior aspect of the diaphragmatic surface is not in contact with the peritoneum and makes direct contact with the diaphragm. This is known as the ‘bare area’ of the liver.

The liver is also covered by a connective tissue capsule

Question 4

What is the falciform ligament?

Answer 4

Divides the left and right lobe of the liver and attaches the anterior surface to the anterior abdominal wall.

Question 5

What is the coronary ligament

Answer 5

Attaches the superioir surface of the liver to the inferioir surface of the diaphragm

Question 6

How does the lesser omentum interact with the liver?

Answer 6

The lesser omentum connects the liver to the lesser curvature of the stomach and the first part of the duodenum.

Question 7

How does the liver interact with the vena cava?

Answer 7

The posterior surface of the liver is secured to the inferior vena cava by hepatic veins and fibrous tissue.

Question 8

Describe the Caudate lobe

Answer 8

Located on the upper aspect of the surface

Question 9

Describe the Quadrate

Answer 9

Located on the lower aspect of the visceral surface

Question 10

Porta Hepatis

Answer 10

Transverse fissure separating the caudate and quadrate lobe on the inferior surface

It transmits the left&right hepatic ducts, hepatic arteries and portal vein. (anterior–> posterior). Components of portal triad

Question 11

Arrangement of the Hepatocytes

Answer 11

Hepatocytes are arranged into structural hexagonal units called lobules,

At each corner exists a portal triad

At centre of the hexagonal unit, the central vein drain blood to the hepatic veins => IVC

Question 12

Drainage of the Bile

Answer 12

Bile is drained through the bile canaculi into large collecting ducts of the intrahepatic portal triad.

These merge to porn the left&right hepatic ducts which drain the left and right lobes of the liver and latterly the common hepatic duct.

On it’s right side it forms a union with the cystic duct from the gallbladder to form the bile duct

The bile duct then forms the hepaticpancreatic ampulla with the pancreatic duct.

Question 13

What is the Sphincter of Oddi and it’s action and it’s other name.

Answer 13

Major Duodenal Papilla

The smooth muscle that surround the end portion of the common bile and pancreatic duct. It relaxaes to allow bile and pancreatic juice to flow into the intestine.

Question 14

What are Septa?

Answer 14

The septa is connective tissue that divide’s the liver into their hexagonal lobules

Question 15

Components of the portal triad

Answer 15

Portal Vein & Artery and hepatic duct.

Question 16

Histology of the Liver

Answer 16

Hepatic Cords of hepatocytes radiate from the central vein.

In the space between this space exist the bile canaliculi (cleft like lumen)

and

hepatic sinusoids (blood channels)

Question 17

Hepatic Sinusoids

Answer 17

Vascular channels that recieve blood from the terminal branches of the hepatic artery and portal vein and drain to the central vein

Question 18

Functions of the Liver

Answer 18

Secretion and production of bile.
Nutrient storage (vitamins, glycogen, fat, Cu & Fe)
Nutrient inter conversion
detoxification

Question 19

What are the Six Components of Bile

Answer 19

Bile Acids
Lecuthin
Cholesterol
Bile Pigments (billirubin)
Toxic metals (detoxed in liver)
Bicarboante (secreted by duct cells)

Question 20

Where does the central vein drain to?

Answer 20

The central vein drains to the hepatic veins, into the IVC

Question 21

Components of Bile synthesised in the liver and fat soluble

Answer 21

Bile Acids
Lecithin
Cholesterol
Bile pigment (bilirubin)

Question 22

What is bilirubin composed of?

Answer 22

Made from breakdown products of haemoglobin from erythrocytes.

Question 23

Synthesis of Bile acids

Answer 23

Synthesised from cholesterol. Before secretion, bile acids are conjugated with glycine or taurine.

Question 24

Are bile salts reabsorbed?

Answer 24

Bile salts are recycled via portal circulation once they have carried out their role in micelle formation ( fat absorption)

Question 25

The role of the gallbladder in bile salt concentration

Answer 25

The gallbladder removes water from bile salts to increase concentration

Question 26

Control of Bile secretion

Answer 26

Sphincter of Oddi, relaxation allows bile and pancreatic fluid to enter the duodenum

Fat in duodenum triggers release of CCK. Relaxing the sphincter and contracting the gallbladder and discharges bile into the duodenum.

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Question 27

What does CCK mean?

Answer 27

Cholecytokinin