Gastrointestinal Lecture 6 Part 1 Functional Anatomy of the Liver

Question 1

What do we know about the liver already?

Answer 1

Question 2

Functional anatomy of the liver

Answer 2

Question 3

Functional anatomy of the liver: circulation

Answer 3

• The absorptive segments of the gastrointestinal tract drain into the hepatic portal vein
• The liver receives arterial blood supply from the aorta, and venous drainage via the vena cava
• The liver also receives blood supply from the hepatic portal vein, which drains from the stomach and intestines = “hepatic portal system”
• Substances absorbed in the intestine (nutrients, toxins, drugs) must pass through the liver and be processed before entering the general circulation

Question 4

Functional anatomy of the liver: hepatic lobules

Answer 4

• Structure has central veins
• Portal triad
• chords of hepatocytes

Question 5

Parts of the portal triad

Answer 5

• branch of bile duct
• branch of hepatic portal vein
• branch of hepatic artery

Question 6

How does the portal triad of the liver work?

Answer 6

• Arterial blood flows from hepatic artery to central vein oxygenating hepatocytes*
• Blood from the portal vein percolates between hepatocytes, emptying into the central vein*
• Bile produced by hepatocytes drains into the bile duct*

Question 7

What happens to Arterial and portal vein blood

Answer 7

percolates towards the central vein in hepatic sinusoids

Question 8

How does blood interact with hepatocytes

Answer 8

Blood travelling through the hepatic sinusoids can flow through gaps in the endothelial cell layer (fenestrations), entering the space of Disse and coming in direct contact with the hepatocytes.