Hepatic 2

Question 1

Basolateral aspect of hepatocytes

Answer 1

faces Space of Disse

Question 2

Apical aspect of hepatocytes

Answer 2

faces canniculi lumen

Question 3

What molecules can be reabsorbed from the bile with Na+ transport?

Answer 3

adenosine and AAs

Question 4

Are transporters in the apical membrae unidirectional?

Answer 4

yes (mostly)

Question 5

icterus

Answer 5

jaundice

Question 6

hyperbilirubinemia

Answer 6

excess bilirubin in blood serum

Question 7

Jaundice

Answer 7

yellowing of the skin and/or whites of the eyes, d/t excess bilirubin

Question 8

3 Possible Causes of Jaundice

Answer 8

1. Obstruction of the Bile Duct
2. Liver Disease
3. Excessive breakdown of RBCs

Question 9

How can the liver get rid of RBCs?

Answer 9

Kupffer cells will phagocytose the dying RBCs and breakdown into hemoglobin, then into heme and globin

Question 10

3 Major Organs that can breakdown RBCs

Answer 10

1. Liver
2. Spleen
3. Bone Marrow

Question 11

What is globin broken down into?

Answer 11

amino acids

Question 12

What happens to the heme of old RBCs?

Answer 12

the iron component of heme can be used by the bone marrow; can also be broken down to bile and go to the gallbladder

Question 13

How does heme become bile?

Answer 13

Heme goes through a redox rxn to become bilirubiin, which is then secreted to the blood where it binds to albumin, then hepatocytes pick up the complex, albumin removed, conjugated by UGT, and goes to gallbladder as bile

Question 14

What makes shells and bird poop green?

Answer 14

biliverdin

Question 15

urobilinogen

Answer 15

when bacteria metabolize bilirubin in the intestine

Question 16

3 Pathways of Urobilinogen

Answer 16

1. 20% reabsorbed by intestine and into the portal vein
2. 20% excreted via the kidneys
3. 60% metabolized into stercobilin

Question 17

What gives urine its yellow color?

Answer 17

urobilin, the oxidized form of urobilinogen when exposed to air

Question 18

What component makes feces brown?

Answer 18

stercobilin

Question 19

3 Types of Hyperbilirubinemia

Answer 19

1. Pre-hepatic
2. Hepatic
3. Post-hepatic

Question 20

Pre-Hepatic Hyperbilirubinemia

Answer 20

increased RBC destruction –> lots of heme –> lots of circulating bilirubin

Question 21

Which types of hyperbilirubinemia would have high unconjugated bilirubin levels in the blood?

Answer 21

pre-hepatic and hepatic

Question 22

Which types of hyperbilirubinemia would have high levels of conjugate bilirubin in the blood?

Answer 22

post-hepatic

Question 23

Hepatic Hyperbilirubinemia

Answer 23

hepatic dysfunction/damage affects liver’s ability to transform the bilirubin so it will “back up” in the blood serum

Question 24

Post-Hepatic Hyperbilirubinemia

Answer 24

blockage of biliary outflow; conjugated bilirubin goes back into systemic ciculation

Question 25

Cholestasis

Answer 25

blockage of biliary outflow

Question 26

Cholelilthiasis

Answer 26

gallstones

Question 27

Which type of hyperbilirubinemia results in dark-colored urine?

Answer 27

post-hepatic (conjugated is more polar so can go through the kidney)

Question 28

Diagnostics to differentiate between pre-hepatic and hepatic?

Answer 28

Pre-hepatic will have dec. RBCs Hepatic will have inc. AST, inc. ALT, and dec. albumin

Question 29

2 Major Functions of Bile

Answer 29

1. Bile is the excretory route for solutes that can't be excreted by the kidney 2. Needed to form micelles for lipid digestion and absorption

Question 30

Constituents of Bile

Answer 30

bile acids/salts, phospholipids, cholesterol, IgA,bile pigments, water, inorganic salts, mucus

Question 31

Which constitueents of bile are amphipathic?

Answer 31

bile acids, bile salts, and phopholipids

Question 32

IgA in bile

Answer 32

inhibits bacterial growth within the bile

Question 33

Bile Acids vs. Bile Salts

Answer 33

Bile Acids are protonated, neutral, not [very] water soluble Bile Salts are deproteonated, negatively charged, more water soluble

Question 34

Which is more water soluble - bile acid or salt?

Answer 34

bile salts

Question 35

Why are bile salts negatively charged?

Answer 35

d/t conjugation with sulfate or glucuronate (or glycine or taurine)

Question 36

Only cell type that can synthesize bile acids?

Answer 36

hepatocytes

Question 37

Primary Bile Acids

Answer 37

synthesized in hepatocytes

Question 38

Secondary Bile Acids

Answer 38

synthesized in intestine by bacteria that dehydroxylates the primaries

Question 39

Do hepatocyte secretions have more bile salts or bile acids?

Answer 39

bile salts

Question 40

How are secondary bile acids reabsorbed in the gut?

Answer 40

enterohepatic recirculation

Question 41

Enterohepatic circulation

Answer 41

95% of bile acids and salts are absorbed in ileum and colon (some throughout entire GI but these are main locations) and enter portal venous system

Question 42

Cholangiocytes

Answer 42

name of biliary epithelial cells

Question 43

3 Ways Bile Secretion is Controlled

Answer 43

1. Positive feedback - increase secretion of bile salts 2. Negative feedback - decrease synthesis of bile salts 3. CCK - secreted by intestine after a meal and inc. release of bile acid from gallbladder