Biliary Secretion And Enterohepatic Circulation Of Bile

Question 1

Where are bile acids secreted into?

Answer 1

Cannalicular

Question 2

What is bile?

Answer 2

Complex lipid-rich micellar solution
Isosmotic with plasma

Question 3

What is the function of bile?

Answer 3

Lipid digestion and absorption
Cholesterol homeostasis
Excretion of lipid soluble xenobiotics / drug metabolites / heavy metals

Question 4

What are bile acids synthesised from?

Answer 4

Cholesterol in pericentral hepatocytes of the acini

Question 5

What is the definition of amphipathic?

Answer 5

Has hydrophilic and hydrophobic parts

Question 6

What is the advantage of bile acids being amphipathic?

Answer 6

Reduces surface tension
Aids emulsification

Question 7

What is the purpose of emulsification?

Answer 7

It increases surface area for lipolysis

Question 8

What is the name of the amphipathic protein that allows lipase to get into the emulsion droplet?

Answer 8

Colipase

Question 9

What are functions of bile acids?

Answer 9

Induce bile flow & secretion of biliary lipids

Digestion and absorption of dietary fats

Cholesterol homeostasis

Antimicrobial properties

Question 10

What happens in the fasted state of enterohepatic circulation?

Answer 10

Bile acids travel down the biliary tract from liver to gallbladder

Question 11

What happens in enterohepatic circulation?

Answer 11

Bile acids remain intraluminal

Actively transported via the apical sodium bile acid transporter in the terminal ileum

Re-enters liver via portal circulation

Bile acids taken up by hepatocytes and secreted into biliary canaliculi