Bile

Question 1

What is bile made up of?

Answer 1

bile salts
cholesterol
xenobiotics (drugs, alcohol)
electrolytes (HCO3- mainly)
phospholipids (lecithin)
bilirubin

Question 2

What cells is bile secreted by and how often?

Answer 2

in the liver by hepatocytes

continuously

Question 3

What is bile used to do?

Answer 3

emulsify fats

Question 4

Where is bile stored and concentrated?

Answer 4

In the gall bladder since NaCl and water are absorbed into the blood

Question 5

Where does the gall bladder lie?

Answer 5

Lies in the junction of the right mid clavicular line & costal margin

Question 6

How is the liver connected with the GI tract in regards to veins?

Answer 6

superior mesenteric vein drains into the portal vein to liver

Question 7

What is the portal triad?

Answer 7

A hepatic portal vein
Hepatic artery
Bile duct

Question 8

What is in the centre of the hepatic lobule?

Answer 8

Central vein eventually becomes the hepatic vein

Question 9

Where do substances absorbed from the small intestine end up in the liver?

Answer 9

In the hepatic sinusoid (type of BV, with fenestrated discontinuous endothelium)

Question 10

Where does majority of the livers blood supply come from?

Answer 10

Portal vein - 80%

Hepatic artery - 20%

Question 11

What is the pathways of bile?

Answer 11

Bile canaliculi, bile ductules, left & right hepatic duct, common hepatic duct, Cystic duct from gall bladder joins, common bile duct

Question 12

Where does the common bile duct go to?

Answer 12

Ampulla of vater

Opening into duodenum

Question 13

What other duct is found at the ampulla of vater?

Answer 13

Pancreatic duct

Question 14

What sphincter is found at the ampulla of vater and what does it do?

Answer 14

Sphincter of oddi

Regulates entry of bile and pancreatic substances into the duodenum

Question 15

Where do the 2 ducts enter?

Answer 15

Enter the duodenum at the major duodenal papilla (2nd part of duodenum)

Question 16

Where does the hepatic bile enter the gallbladder from?

What does the gall bladder do to it?

Answer 16

Via the cystic ducts

Stores and concentrates it

Question 17

Bile remains in the gall bladder until…. Which is caused by?

Answer 17

Contracts
Under the action of CCK (cholecystokin)
It is released due to the presence of AA and FA in duodenum

Question 18

What blood vessels supply and drain blood from gall bladder?

Answer 18

Cystic artery, blood to gallbladder

No venous drainage

Question 19

What % of bile salts are reabsorbed and are excreted?

Answer 19

95% reabsorbed

5% excreted in faeces

Question 20

Where are bile salts reabsorbed?

Answer 20

In Jejunum (some) and terminal ileum (mostly)

Question 21

What is the pathway of bile salts going from the terminal ileum to the liver, including channels?

Answer 21

using apical Na+ - bile acid transporter
Into the portal vein
Then into the hepatocytes by 2^ active transport coupled to Na+

Question 22

The liver synthesis new bile salts from…. To replace the small amount that escaped

Answer 22

Cholesterol

Question 23

The liver secretes….. extracted from the blood into bile

Answer 23

Cholesterol

Question 24

Cholesterol homeostasis in the blood is controlled by?

Answer 24

Bile secretion

Excretion of cholesterol in the faeces

Question 25

Is bile secretion continuous?

When is it greatest?

Answer 25

Yes

During & after a meal

Question 26

When the sphincter of oddi is closed, where does the bile go?

Answer 26

The dilute bile is shunted into the gallbladder, here it is concentrated as some of the NaCl and water is absorbed into the blood

Question 27

After a meal, what is released due to the presence of what?

Answer 27

After a fatty meal, hormone Cholecystokinin (CCK) is released in response to presence of fat in duodenum

Question 28

What does the CCK cause to happen?

Answer 28

Causes gall bladder to contract
Sphincter of oddi to relax
Therefore bile enters common bile duct and into duodenum for lipid digestion