Bilirubin Metabolism Flashcards Preview

My NBCE - GI Physiology > Bilirubin Metabolism > Flashcards

Flashcards in Bilirubin Metabolism Deck (18)
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1
Q

Bilirubin is a by product of what?

A

Red blood cell breakdown in the spleen

2
Q

Old red blood cells >? days are broken down to release what two things?

A

120

Heme and globin

3
Q

The heme is further broken down the release what?

A

Iron and biliverdin

4
Q

Biliverdin is converted into what? How is it carried in the blood?

A

Bilirubin

Attached to albumin

5
Q

Bilirubin attached to albumin is insoluble to what? Soluble in what?

A

Water (indirect) - insoluble

Lipids - soluble

6
Q

The Bilirubin is transported to the liver where it is conjugated with a __________ by _______?

A

glucuronide

UDPG transferase

7
Q

Conjugation of the Bilirubin does what to it?

A

Renders it into a water-soluble state

8
Q

Conjugated (direct) bilirubin is secreted into what and stored where?

A

biliary tract

gallbladder

9
Q

Bile is bilirubin plus what?

A

Bile salts

10
Q

Bile does what to fat?

A

saponifies it (like soap) rendering it more easily digested by pancreatic lipase

11
Q

The bilirubin in the gut is converted to what by bacteria?

A

urobilinogen

12
Q

What happens to 90% of the urobilinogen?

A

Absorbed into the blood stream

13
Q

5% of the urobilinogen does what?

A

Is excreted in the urine where it is covered to urobilin

14
Q

What colors the urine yellow?

A

urobilin

15
Q

10% of the urobilinogen in the gut is converted into what?

A

stercobilinogen

16
Q

Stercobilinogen is oxidized into what?

A

Stercobilin

17
Q

What colors the stool brown?

A

stercobilin

18
Q

What percentage of the bile salts are reabsorbed and sent back to the liver (enterohepatic circulation)?

A

95%