Bile Secretion and Gall Bladder FXN

Question 1

What is the function of the gall bladder?

Answer 1

It concentrates the bile acid and triggers bile acid secretion.

Question 2

What percent of acids and salts are reabsorbed?
Where are they reabsorbed?
What percent is lost?

Answer 2

40% are reabsorbed
50% are reabsorbed in ileum
10% ar elost

Question 3

What are the two categories of primary bile acids?

Answer 3

Cholic and Deoxycholic

Question 4

How do we alter bile acids to make them more absorbable?

Answer 4

the liver and bacteria dehydroxylate them, making them less h20 soluble and more reabsorbable.

Question 5

What characteristic of bile salts allow them to form micelles?

Answer 5

amphipathic

Question 6

Describe the biliary histology

Answer 6

the central vein lies, surrounded by the be cells, including branches of the portal vein, branch of the heapti artery and bile canaliculi.

Question 7

How many grams of bile acid are there in the human body?

Answer 7

2.5

Question 8

Describe the circulation of the biliary system

Answer 8

Bile acids are released from the liver into the gallbladder. Passing through the sphincter of oddi, they enter the duodenum, and are reabsorbed in the ileum. Once absorbed in the ileum, they return to the liver via the portal blood

Question 9

What is the primary transporter involved in BA secretion?
Secondary?
How are they interrelated?

Answer 9

The primary transport is a Na/K pump, pumping K into the cell and Na back into blood.
The secondary is pumping a BA and a Na into the cell.
They are related because the Na brought in with BA is the Na brought out via active transport

Question 10

What are various chemicals put into bile that are bile acid dependent?

Answer 10

H20, K, Na Cl Ca Hco3

moving from blood to bile via facilitated diffusion

Question 11

What is bilirubin from?

Answer 11

Broken down Hemoglobin

Question 12

Why does bilirubin stain stool?

Answer 12

Bacteria act to reduce it in colon.

Question 13

Is bilirubin present in the micelles?

Answer 13

nope

Question 14

Describe the pathway of bilirubin

Answer 14

Bilirubin is transported to liver and binds with glucuronic acid forming Bilirubin Glucuronide. This travels through intestines where it’s returned to bilirubin by bacteria. Once here, it’s acted on by H2 turning into urobilinogen. Urobilinogen can be eliminated in the feces or ereturn to liver where it is given to kidneys to be excreted as urobilin in urine.

Question 15

What does CCK work on?

Answer 15

Triggers the gallbladder to release bile and causes the sphincter of oddi to relax

Question 16

Why does the ph of bile decrease from the liver to the gallbladder?

Answer 16

because there is a reabsorption of hco3

Question 17

What are the two types of gallstones?

Answer 17

cholesterol stones and pigment stones

Question 18

What are pigment stones saturated with?

Answer 18

unconjugated bilirubin, due to high B-glucoronidase or due to gall bladder wall damaged by bacteria

Question 19

Explain the levels of bile acid secretion with gallbladder intact vs cholecystectomy

Answer 19

With the gallbladder intact, the bile acid peak quickly after food ingestion, reaching 2.5 mmols/hr.
With gallbladder removed, bile acids are secreted to 1.0 mmol/hr, showing that the gallbladder isn’t necessary for bile acid secretion.