Liver

Question 1

What are the three principal hepatocyte functions?

Answer 1

Transport and biotransformation, Synthesis and storage, and excretion

Question 2

What is bilirubin?

Answer 2

A breakdown product of heme

Question 3

What is the main mechanism by which bilirubin enters the hepatocyte?

Answer 3

Organic Anion Transporting Polypeptide

Question 4

What can enter into the hepatocyte via the organic anion transporting polypeptide?

Answer 4

Bilirubin, organic anions, bile salts

Question 5

What is the hepatic detoxification of bilirubin?

Answer 5

The conjugation process leading to the addition of either glucuronic acid or sulfate

Question 6

What is involved in Phase I of Hepatic biotransformation? What is the primary catalyst? What is the overall effect on the molecule?

Answer 6

Oxidation, reduction, or hydrolysis by cytochrome P450 making the molecule more polar and reactive and a candidate for phase II

Question 7

What is involved in phase II of hepatic biotransformation? What is the overall effect on the molecule?

Answer 7

Conjugation of glucuronate, methyl group, sulfate, acetate, glycine, or glutathione; Increases solubility

Question 8

True or False: A compound must go through both phase I and II before it can be excreted.

Answer 8

False

Question 9

How is bilirubin transported into the canaliculi?

Answer 9

MRP-2 and MDR-3

Question 10

What are the 4 different mechanisms to bring stuff into hepatocytes?

Answer 10

Na-dependent transporters; Na-independent transporter; GLUT-2; Endocytosis

Question 11

What are the Na-dependent hepatocyte transporters?

Answer 11

Na+/K+ ATPase, Na+/HCO3-, Na+/AA symporter, Na+/BS-

Question 12

What are the potential causes of jaundice?

Answer 12

Excess production (increased RBC destruction), decreased transport into the hepatocyte, decreased metabolism (immature conjugation), decreased secretion into canaliculi, bile duct obstruction

Question 13

What are the ATP-dependent transporters out of the hepatocyte?

Answer 13

Bile salt export pump (BSEP) and Multi Drug Resistance (MDR) proteins

Question 14

True or False: The transport of bile salts and conjugated bilirubin requires energy.

Answer 14

True

Question 15

What is the functions of bile?

Answer 15

Lipid (fat) digestion and absorption, lipid soluble vitamin absorption; and elimination of waste

Question 16

Where is cholesterol converted to bile acids? Through what enzyme?

Answer 16

In the hepatocyte by 7alpha hydroxylase

Question 17

What are the 2 principal bile acids?

Answer 17

Cholic and chenodeoxycholic acid

Question 18

What makes a bile acid a bile salt?

Answer 18

Conjugation of glycine or taurine

Question 19

What transforms bile salts into secondary bile acids or salts? What are they?

Answer 19

Intestinal bacteria converts them into deoxycholic and lithocholic acid

Question 20

How is bile formed?

Answer 20

Bile salts are transported into canaliculi and enter ductules and other cells excrete water, glutathione, glucose, AA, urea, bilirubin, and cholesterol, phosphatidyl choline

Question 21

What are the cells that modify bile in the ductules?

Answer 21

Cholangiocytes

Question 22

What is the name of the neurological result of excess bilirubin?

Answer 22

Kernicterus

Question 23

What is the function of the gall bladder?

Answer 23

Concentration and storage of bile, acidification of bile, and mucus secretion

Question 24

How do bile acids recirculate?

Answer 24

Reabsorption of bile salts at terminal ileum

Question 25

What are the specialized macrophages of the liver?

Answer 25

Kupffer cells

Question 26

True or False: C-reactive protein is released from hepatocytes in response to kupffer cell activity

Answer 26

True

Question 27

What are stellate cell and where within the liver can they be found?

Answer 27

Pericytes found in the space of disse

Question 28

What can result from chronic Kupffer cell activity on stellate cells?

Answer 28

LIver fibrosis

Question 29

What type of proteins are synthesized in the liver?

Answer 29

Albumin, globulin, clotting factors, binding/transport proteins, hormone precursors, lipoproteins

Question 30

How can liver dysfunction cause altered mental status?

Answer 30

Inability to eliminate ammonia, bilirubin

Question 31

What is the general process of amino acid breakdown?

Answer 31

Transamination, oxidative deamination, and te urea cycle

Question 32

What enzymes are involved transamination? When would their plasma levels be increased?

Answer 32

Aspartate and alanine aminotransferase- released into circulation when the hepatocytes are damaged

Question 33

How is ethanol metabolized? Through what enzymes? Which enzyme is upregulated with chronic alcohol abuse?

Answer 33

Via alcohol dehydrogenase or cytoP450 into acetaldehyde or via catalase enzymes; CytoP450 phase I upreg

Question 34

Why is acetaminophen with alcohol a bad thing?

Answer 34

Acetaminophen is also metabolized by cyP450 enzymes- the phase I product is v toxic and normally quickly metabolized to phase II non toxic product using glutathione; Chronic alcohol upregulates cP450 and depletes glutathione and so there is too much toxic metabolite that cannot undergo phase II transformation quickly enough because there isn’t enough glutathione

Question 35

What is the treatment of acetaminophen overdose?

Answer 35

Acetylcysteine

Question 36

True or False: Liver makes more cholesterol de novo than it gets from diet?

Answer 36

True