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Flashcards in Liver and Bilirubin Deck (28):
1

Functions of the liver (Several hundred known!) Name a few

Metabolism
Excretion
Hematologic
Immunologic
Detoxification
Storage

2

Bilirubin: Normal metabolism

Old RBC Destroyed --> Heme --> Bilirubin --> +Albumin --> Unconjucated bilirubin --> LIVER
(In liver unconjugated bilirubin is conjugated) --> intestine --> reducded to urobilinogen --> POOP OR --> Enterohepatic Circulation to be recirculated --> Systemic circulation --> kidney --> PEE

3

When bilirubin is REVERSIBLY/IRREVERSIBLY bound to albumin, it is called _________.

REVERSIBLY. UNCONJUGATED bilirubin.

4

Unconjugated bilirubin is:
water (soluble/insoluble)
(toxic/non-toxic) to cells
(passable/too large to pass) glomerular BM

sparingly water soluble
toxic
too large to pass

5

The liver rapidly clears _______ from the bloodstream.

Unconjugated bilirubin

6

In the liver, _____ is conjugated into ______ by the liver enzyme named _______

Bilirubin, conjugated/direct bilirubin, Glucoronyl Transferase

7

Conjugated bilirubin is:
water (soluble/insoluble)
(toxic/non-toxic) to cells
(passable/too large to pass) glomerular BM

relatively water soluble
non-toxic
passable

8

Conjugated bilirubin spills into bloodstream only when

there is injury of the liver cells, which interferes with transfer of bilirubin to bile canaliculi

9

You see conjugated bilirubin in the plasma =

Liver Cell Damage! Arg!

10

What kind of bilirubin is found in the urine?

ONLY conjugated!

11

When will you see both conjugated and unconjugated bilirubin in the plasma?

massive hemolysis

12

In the intestines, bilirubin is reduced by bacteria to ________

urobilinogen (UBG)

13

How much urobilinogen is absorbed from the colon and returned to the liver and re-excreted by liver cells into bile?

20%

14

How much of the urobilinogen is reabsorbed and remains in the plasma and is excreted in the urine?

A small fraction

15

What are the two tests for Lab analysis of bilirubin?

Total bilirubin test: measures conjugated and unconjugated forms
Direct Bilirubin test: measures only conjugated

16

How do you measure Unconjugated Bilirubin?

Total - Direct = Indirect = Unconjugated

17

When would you use bilirubinometers?

To measure total bilirubin ONLY in neonatal populations. Wont work with adults because of lipochromes such as carotene in adult serum that cause a strong pos. interference

18

What are things than can screw with your billirubin specimen collection?

Hemolysis causes falsely decreased results
Want to get a fasting so it is free of lipemia
Light causes falsely decreased results

19

Causes of hyperbilirubinemia

increased bilirubin load on liver cell, distubance in uptake of bilirubin within liver clel, distrubance in transport of bilirubin, defects in conj., defects in excretion, hepatocellular damage, obstruction

20

Inc. in plasma unconjugated bilirubin

Hemolytic disease, Genetic errors (Gilbert's syndrome, grigler-naijar syndrome, lucey-driscoll syndrome) Physiologic jaundice of newborn, ineffective erythropoiesis, drugs competing for glucuronide

21

Inc. in plasma conjugated billirubin

Cholestasis, genetic errors, biliary atresia, hepator cellular damage

22

Prehepatic disease:

Inc. Unconjegated bili
Normal Conjugated bili
Inc. Urine UBG
NO Urine bilirubin

23

Posthepatic disease

Inc. Conjugated bili
Normal Unconjugated bili
Inc Urine bilirubin
NO Urine UBG
FECES: Chalky white

24

Hepatic disease (Post-conjugation transport defect)

Inc. Conjugated bili
Normal unconjugated bili
Inc Urine bilirubin
Urine UBG normal or increased?

25

Hepatic disease (Bilirubin conjugation failure)

Inc. Unconjugated bili
Normal Conjugated
Neg. urine results
Chalky white feces

26

Aminotransferases

AST=SGOT and ALT=SGPT

27

1. AST measurement:
2. ALT measurement:

1. MI, hepatocellular disorders, skeletal muscle involvement
2. hepatic disorders only

28

5 isoenzymes of LD that have tissue specificity

LD-1 and 2 - Heart, RBC (renal cortex)
LD-3 - non-specific, lung, lymphocytes, spleen, pancreas
LD-4 and 5 - Liver, skeletal muscle