Hepatic Secretions Flashcards Preview

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Flashcards in Hepatic Secretions Deck (44)
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1

Hepatocyte border

sinusoids (blood), space of Disse (lymph), and bile cancliculi (bile)

2

Discontinuous capillaries

allows passage of proteins into blood

3

Tight junctions

prevent mixing of bile, blood, lymph

4

Bile allows secretion of

organic, high MW, and hydrophobic molecules that annot be excreted in urine

5

Bile is composed of

bile acids, phospholipids, cholesterol, HCO, bilirubin, water

6

Bile acids function

ampipathic, formation of micelle for digestion of fat (phospholipids, choleterol, long chain FFA)

7

Liver synthesizes primary bile acids

cholic acid and chenodeoxycholic acid from cholesterol

8

cholesterol 7alpha-hydroxylase

synthesize cholic acid

9

oxysterol 7alpha-hydroxylase

synthesizes chenodeoxycholic acid

10

Enterohepatic circulation

circulation of bile acids from liver, gall bladder, duodenum, colon, to liver via portal vein

11

During fasting, bile acids in portal venous blood is ______ so rate of syntehesis is

Low, synthesis high

12

During a meal, bile acids in portal venous blood is ______ so rate of syntehesis is

High, synthesis low

13

Passive absorption of bile acids occurs in

colon and proximal small intestine

14

Carrier mediated absorption of bile acids occurs in

ileum and liver

15

Sodium-dependent bile acid transporter (ASBT)

mediated uptake of bile acid in enterocytes of ileum (MAJOR MECHANISM)

16

Sodium-dependent transport proteins (NTCP) and Sodium-independent organic anion transport

mediate uptake of bile acids in the liver

17

ATP-dependent bile salt export (BSEP)

liver secretes bile acid into canaliculi

18

Multi-drug resistant-associated protein 2 (MRP2)

secretion of sulfated or glucuronidated bile acids into canaliculi

19

Secondary bile acids are formed by

bacteria in the colon

20

defect in bile acid formation may be due to

increased bile acid excretion in feces, loss of bile acid flow, decreased cholesterol absorption,

21

defects in membrane transport of bile acid

mutation in transporter protein

22

Defects involving bacterial transformation

bacterial overgrowth depletes bile acids

23

Defects in bile acid circulation

obstruction, crohn's, celiac

24

Bilirubin

RBC death and binding of unconjugated bilirubin to albumin

25

UGT1A1

liver enzyme that conjugates bilirubin to two glucuronic acids

26

Excretion of liver

conjugated bilirubin is excreted into the bile (RATE-limiting step)

27

conjugated bilirubin in the colon is converted to

urobilinogen

28

Urobilinogen can be excreted in urine as ______ or feces as _______

urobilin; stercobilin

29

Jaundice

accumulation of bilirubin in the blood

30

Indirect bilirubin >80-85% of total indicated

unconjugated hyperbilirunemia; hemolysis of RBC, impaired conjugation, impaired hepatic uptake of bilirubin